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塩澤 大輝大学院工学研究科 機械工学専攻准教授
研究活動情報
■ 受賞- 2014年05月 日本材料学会, 平成25年度日本材料学会学術奨励賞, 放射光μCTイメージングおよび散逸エネルギを用いた疲労損傷の非破壊評価に関する研究国内学会・会議・シンポジウム等の賞
- 2013年04月 日本機械学会, 2012年度 日本機械学会奨励賞(研究), 高輝度放射光μCTイメージングを用いた疲労損傷評価の研究その他の賞
- MDPI, 2024年02月, The 17th International Workshop on Advanced Infrared Technology and Applications研究論文(国際会議プロシーディングス)
- MDPI, 2023年12月, The 17th International Workshop on Advanced Infrared Technology and Applications研究論文(国際会議プロシーディングス)
- MDPI, 2023年12月, The 17th International Workshop on Advanced Infrared Technology and Applications研究論文(国際会議プロシーディングス)
- MDPI, 2023年10月, AITA 2023研究論文(国際会議プロシーディングス)
- MDPI, 2023年10月, 土木学会全国大会年次学術講演会(Web), 78th
- MDPI, 2023年10月, AITA 2023研究論文(国際会議プロシーディングス)
- Elsevier BV, 2023年09月, NDT & E International, 138, 102893 - 102893研究論文(学術雑誌)
- Austenitic stainless steels with a bimodal harmonic structure, in which the fine grain structure (Shell) exists around the coarse grain structure (Core), are prepared by powder metallurgy to improve both strength and ductility. Herein, X-ray diffraction contrast tomography, a 3D grain mapping technique for polycrystalline materials using ultrabright synchrotron radiation X-rays, is used to reconstruct the grain shape and location and to evaluate the average excess dislocation density of the Core and Shell structures. This technique allows one to evaluate the excess dislocation density not only on the surface, but also inside the sample where damage occurs in tensile tests. The results show that the excess dislocation density of the Shell structure is higher than that of the Core structure. The excess dislocation density of homogeneous austenitic stainless steels with grain sizes similar to the Core structure of the harmonic structured stainless steel is higher than that at comparable stresses, indicating that the deformation of the bimodal harmonic structured alloy is localized in the fine grain structure. This is consistent with the results obtained from electron backscatter diffraction analysis, in which the surface grains are evaluated.WILEY-V C H VERLAG GMBH, 2023年02月, ADVANCED ENGINEERING MATERIALS, 英語研究論文(学術雑誌)
- Elsevier BV, 2022年12月, NDT & E International, 132, 102708 - 102708研究論文(学術雑誌)
- Elsevier BV, 2022年09月, 日本材料学会学術講演会講演論文集(CD-ROM), 125, 104288 - 104288
- The formation and propagation of cracks in rolling contact fatigue were observed by synchrotron radiation computed laminography, and the effect of stringer-type inclusion orientation was examined. For longitudinal inclusions, cracks started forming at their tips. After cracks propagated toward the rolling direction, a longitudinal crack was kinked simultaneously at both its tips, and propagated toward the direction perpendicular to the rolling direction to form lateral cracks. After kinking, horizontal cracks were formed from the deepest point of a lateral crack, leading to flaking. On the other hand, for specimens with lateral inclusions, cracks propagated to the lateral direction without the formation of longitudinal cracks. Since the propagation life of lateral cracks and that of horizontal cracks were unrelated to the inclusion orientation, the rolling contact fatigue life of specimens with longitudinal inclusions was considerably longer than that of specimens with lateral inclusions.WILEY, 2022年08月, FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES, 45(8) (8), 2200 - 2214, 英語研究論文(学術雑誌)
- Background: The false apparent temperature change caused by moving objects generates noise components in thermoelastic stress analysis (TSA) and rapid fatigue limit estimation based on energy dissipation. Objective: This paper proposes a motion compensation system using visible-infrared synchronous measurements to remove apparent temperature changes. A new dissipative energy evaluation method that combines visible and infrared measurements is proposed. Methods: The displacement information is obtained using digital image correlation (DIC) in visible images. Visible and infrared measurements are performed on the same surface simultaneously. The displacement information obtained from the visible image is reflected in the infrared image by applying image processing for spatial synchronization. A white speckle pattern required for DIC is applied to black paint, and this white paint does not affect the infrared measurement. Results: In the new method, the time series of strain obtained from the visible image is used to calculate the thermoelastic temperature change, which is then compared with the actual temperature change obtained via infrared thermography to evaluate the temperature change due to energy dissipation. Motion compensation systems have been applied to TSA and dissipative energy measurements. It is confirmed that the edge effect and false apparent dissipated energy can be removed using the developed system. It is discovered that the energy dissipation behavior within one cycle of the load, which cannot be evaluated via conventional frequency analysis, can be observed comprehensively. Conclusions: This synchronous measurement system is useful for enhancing the accuracy of TSA and dissipated energy measurement.2022年03月, Experimental Mechanics, 62(3) (3), 459 - 470研究論文(学術雑誌)
- Currently, gas leakage source detection is conducted by the human senses and experience. The development of a remote gas leakage source detection system is required. In this research, an infrared camera was used to detect gas leakage. The gas can be detected by the absorption of infrared rays by the gas and the infrared rays emitted from the gas itself. A three-dimensional reconstruction of a leaked gas cloud was performed to identify the gas leakage source and the flow direction of the gas. The so-called four-dimensional reconstruction of the leaked gas cloud, i.e., reconstruction of three-dimensional images of a gas cloud varying with time, was successfully performed by applying the ART (Algebraic Reconstruction Techniques) method to the multiple optical paths of infrared measurement.MDPI AG, 2021年12月, Engineering Proceedings, 8(1) (1), 33 - 33研究論文(学術雑誌)
- Heavy-duty anticorrosion coatings are applied on the surface of steel bridges for protecting against corrosion. By aging deterioration, the coating is worn from the surface year by year. Appropriate re-painting construction programs should be adopted for the maintenance of the bridges according to the evaluation of wear extent. Experimental studies were conducted with the aim of quantitative estimation of the degree of abrasion of the top coat thickness. It was found that there was a correlation between the top coat thickness and the observed infrared intensity and that this calibration relationship could be used to estimate the top coat thickness.MDPI AG, 2021年11月, Engineering Proceedings, 8(1) (1), 26 - 26研究論文(学術雑誌)
- To optimize welding conditions that ensure the safety and reliability of laser welds, this study established an evaluation method of the fatigue strength for the laser welds of steel sheets over a short period of time. This study focuses on a fatigue limit estimation based on dissipated energy which is caused by micro plastic deformation. As a result, the area at which the temperature changes, due to dissipated energy, is locally high is the fracture origin of the laser welds. The fatigue limit of the laser welds is almost the same as the stress amplitude at which a temperature change occurs due to dissipated energy.MDPI AG, 2021年11月, 破壊力学シンポジウム講演論文集, 8(1) (1), 6 - 6
- Short fiber reinforced plastics (SFRPs) have excellent moldability and productivity compared to continuous fiber composites. In this study, thermoelastic stress analysis (TSA) was applied to detect delamination defects in short carbon fiber reinforced plastics (SCFRPs). The thermoelastic temperature change Delta T-E, phase of thermal signal theta(E), and second harmonic temperature component Delta T-D were measured. In the fatigue test of SCFRP, it was confirmed that changes in Delta T-E, theta(E), and Delta T-D appeared in the damaged regions. A staircase-like stress level test for a SCFRP specimen was conducted to investigate the generation mechanism of the Delta T-D. The distortion of the temperature change appeared at the maximum tension stress of the sinusoidal load-and when the stress level decreased, the temperature change returned to the original sinusoidal waveform. Delta T-D changed according to the change in the maximum stress during the staircase-like stress level test, and a large value of Delta T-D was observed in the final ruptured region. A distortion of the temperature change and Delta T-D was considered to be caused by the change in stress sharing condition between the fiber and resin due to delamination damage. Therefore, Delta T-D can be applied to the detection of delamination defects and the evaluation of damage propagation.MDPI, 2021年09月, MATERIALS, 14(17) (17), 英語, 国際誌研究論文(学術雑誌)
- Laser welding has many advantages, such as the ability to achieve high-quality welds with low deformation, but it has been confirmed that welding defects occur depending on the welding conditions. The welding defects are likely to be the initiation point of damage, it is necessary to optimize the welding conditions and evaluate the fatigue characteristics to ensure the safety and reliability of welding joint. This study focused on evaluation of fatigue strength based on dissipated energy. This evaluation method can evaluate the fatigue strength in a short period of time. So, this study investigated the applicability of this evaluation method to laser welding joint by SPCC. As a result, evaluation of fatigue strength based on dissipated energy of SPCC base metal and laser welding joint was realized, and it was clarified that evaluation of fatigue property based on dissipated energy for laser welding joint was effective. The fatigue fracture origin of laser welding joint was the area of base metal, and it is found that the fatigue strength in the welded area is higher than that in the area of the base metal. As a result of evaluating the fatigue strength of the laser welding joint based on the dissipated energy, it is found that the fatigue strength of the laser welding joint is almost the same as the fatigue limit obtained from the fatigue test.一般社団法人 日本機械学会, 2021年, M&M材料力学カンファレンス, 2021, OS0827, 日本語
- 鉄道台車枠の重点検査箇所以外の場所に対しても,より高い頻度でき裂検査が行うことができればより有用である.そこでき裂を迅速かつ正確に検出可能な検査方法として,アクティブ温度ギャップ法に着目した.材料を局所的に加熱することで熱の移動を生じさせると,き裂部で大きな温度差が生じる.この温度差を赤外線カメラで計測することでき裂部を検出できる.本手法は,構造物に発生したき裂を面計測で遠隔から迅速に検出することが可能であり,目視検査の代替検査となりうると考えられている.本研究では,鉄道台車枠に発生したき裂の検出性を評価した.初めに検査対象の塗装の影響を検討するため,熱湯滴下による加熱実験および有限要素解析を用いた非定常熱伝導解析を行った.その結果,膜厚が100㎛程度では,表面で計測される熱伝導挙動への塗装の影響が小さいことが分かった.次に鉄道台車に用いられる厚さ9mmのSM490Y材に対して,半楕円き裂を模した各種き裂パラメータを用いることで,本手法によるき裂の検出性を検討した.モデルには加熱源に平行なき裂を用いた.その結果,加熱源に平行なき裂に対して,き裂深さ3mmの半楕円き裂に対しては,き裂端部以外のき裂幅を検知することができ,き裂深さの検出限界は1mm程度であった.温度微分値を用いた2次元画像により,材料表面のき裂形状を特定することが出来た.一般社団法人 日本機械学会, 2021年, 関西支部講演会講演論文集, 2021.96, 3107, 日本語
- 近年,赤外線サーモグラフィを用いた散逸エネルギ計測に基づく疲労限度推定法が注目されている.本手法は,応力振幅を階段状に増加させる試験を行い,散逸エネルギが急増する応力振幅が,疲労限度とよく一致するという経験則のもとで予測を行う.本手法を用いることで試験対象の疲労限度および疲労破壊箇所を迅速に推定できるため,様々な材料への適用が検討されているが,接合継手を対象とした事例は僅少である. そこで本研究では,摩擦攪拌接合(FSW)継手の疲労強度評価に対して,散逸エネルギ計測に基づく疲労限度推定法を検討した.FSWは固相接合で,溶融溶接と比較して接合部のひずみが少なく強度低下が小さくなり,欠陥が生じにくいという特徴を有する接合法である.FSWは主にアルミニウム合金などの軽合金材料を対象としており,航空宇宙関係や自動車など様々な産業分野で実用化されている.また近年では,異種材料接合継手へのFSW適用も進められており,FSWの適用範囲拡大と溶接部の品質向上の点においては,接合継手の疲労強度を簡易かつ迅速に評価する手法が求められている. 本研究は,アルミニウム合金A5052Oを母材としたFSWの接合部に対する散逸エネルギ計測に基づいた疲労限度評価を実施した.材,FSWの表面に研磨処理を施したFSW研磨処理材および受入材に対して散逸エネルギ計測を行った.計測結果から得られた,散逸エネルギの発生タイミングを示す位相情報から,ノイズを分離し高精度化する位相ロックイン処理を行った.その結果を用いて,散逸エネルギを用いた疲労限度推定法を適用し,FSW材と受入材の推定値は疲労限度と近い値を示した.FSW研磨処理材の疲労限度推定値は危険側に得られたため,散逸エネルギの増加率を用いて疲労限度推定を行った.その結果,FSW研磨処理材の推定値は疲労限度と比較的近い値を示し,散逸エネルギの急増する応力振幅でFSW材の疲労強度が評価できる可能性が示された.一般社団法人 日本機械学会, 2021年, 関西支部講演会講演論文集, 2021.96, 3108, 日本語
- In this study, new energy dissipation evaluation method using visible-infrared hybrid measurement was developed. The dissipated energy is the temperature change due to plastic deformation. In this evaluation method, the temperature change and deformation of specimen which is subjected to the cyclic or random loading are measured by infrared thermography and visible camera. The deformation of specimen is obtained by the digital image correlation (DIC) from visible image, and the change of strain was calculated from the deformation of specimen. The temperature change due to energy dissipation was obtained by comparison between the temperature change measured by infrared thermography and calculated temperature change from time series of strain measured by visible camera and DIC. It is possible to observe the behavior of energy dissipation in detail. This new energy dissipation evaluation method was applied to austenitic stainless steel. From the results, temperature change with double frequency of load signal could be observed. It was found that the amplitude of differential temperature change obtained by new method was coincide with the double frequency component obtained by frequency analysis.一般社団法人 日本機械学会, 2021年, M&M材料力学カンファレンス, 2021, OS0710, 日本語
- The current gas leakage source detection was conducted by the human senses and experience. The development of remote gas leakage source detection system is required. In this research, infrared camera was used to detect gas leakage. The gas can be detected by the absorption of infrared rays by the gas, and the infrared rays are emitted from the gas itself. Three-dimensional reconstruction of leaked gas cloud was performed to identify the gas leakage source. The 3D reconstruction of leaked gas cloud was performed by the multiple optical paths of infrared measurement and inverse tomography analysis. Algebraic reconstruction techniques (ART) method was applied to reconstruction. In the experiments, the gas concentration distribution was simulated by the arrangement of gas cells. It was found that the gas concentration distribution composed by gas cell could be estimated by infrared images obtained with few optical path and ART method.2021年, Lecture Notes in Mechanical Engineering, 751 - 756研究論文(国際会議プロシーディングス)
- © 2019, The Author(s). Recently, a technique for rapidly determining a material’s fatigue limit by measuring energy dissipation using infrared thermography has received increasing interest. Measuring the energy dissipation of a material under fatigue loading allows the rapid determination of a stress level that empirically coincides with its fatigue limit. To clarify the physical implications of the rapid fatigue limit determination, the relationship between energy dissipation and fatigue damage initiation process was investigated. To discuss the fatigue damage initiation process at grain size scale, we performed high-spatial-resolution dissipated energy measurements on type 316L austenitic stainless steel, and observed the slip bands on the same side of the specimen. The preprocessing of dissipated energy measurement such as motion compensation and a smoothing filter was applied. It was found that the distribution of dissipated energy obtained by improved spatial resolution measurement pinpointed the location of fatigue crack initiation. Owing to the positive correlation between the magnitude of dissipated energy and number of slip bands, it was suggested that the dissipated energy was associated with the behavior of slip bands, with regions of high dissipated energy predicting the location of fatigue crack initiation.2020年02月, Experimental Mechanics, 60(2) (2), 181 - 189[査読有り]研究論文(学術雑誌)
- 公益社団法人 土木学会, 2020年, 構造工学論文集 A, 66(0) (0), 895 - 903, 日本語
Steel-concrete composite decks are increasingly applied for highway bridges to reduce the initial cost of construction. In Robinson type, steel plate and concrete are integrated with studs, but that studs should be careful of fatigue damage due to repeated loading of traffic wheel loads. Because the studs subjected with rotating shear force by running wheel loads, fatigue crack occurs at welding toe of the stud. In this paper, the authors experimentally investigated the progress of fatigue cracking in composite deck using infrared thermography. From the results of infrared stress measurement, the tendency of fatigue crack progress was made clear.
- © Society for Experimental Mechanics, Inc. 2020. Evaluation of fatigue damage propagation is necessary to ensure safety and to estimate the remaining life of the aging steel bridges. In this study, thermoelastic stress analysis (TSA) was applied for on-site measurement of stress distributions around fatigue cracks, and the future crack propagation behavior was estimated by the fracture mechanics approach. Experimental studies were conducted for laboratory specimens which modeled a part of welded structure in steel bridges. The stress intensity factors were calculated from stress distributions measured by TSA technique. Further TSA technique was applied to evaluate the effectiveness of repair works for defective portions. Severity reduction in stress distribution around the fatigue crack after treatment was confirmed for actual steel bridge members by TSA.2020年, Conference Proceedings of the Society for Experimental Mechanics Series, 119 - 122[査読有り]研究論文(国際会議プロシーディングス)
- © Society for Experimental Mechanics, Inc. 2020. On the infrared thermography image, an apparent temperature change caused by the relative displacement between moving object and infrared camera is obtained. This paper shows the motion compensation system with the optical-infrared synchronous measurement. Displacement information of the specimen is calculated from the series of optical image using the digital image correlation method. The displacement information on the optical image is reflected to the infrared image by the homography conversion. For obtaining the displacement information by digital image correlation method, random pattern on the surface of measured object is required. In this study, white random pattern was drowned by the sputtering painting method. The motion compensation system was applied to the thermoelastic stress analysis and dissipated energy measurement. It was confirmed that the apparent temperature change and edge effect can be removed by using developed motion compensation system.2020年, Conference Proceedings of the Society for Experimental Mechanics Series, 163 - 169[査読有り]研究論文(国際会議プロシーディングス)
- Elsevier, 2020年01月, Procedia Structural Integrity, 英語Observations of Twinning and Detwinning in Magnesium Alloy by Synchrotron Radiation DCT and EBSD[査読有り]研究論文(学術雑誌)
- The aim of this paper is to evaluate the Mode II interfacial fracture toughness and interfacial shear strength of Typha spp. fiber/PLLA and Typha spp. fiber/epoxy composite by using a double shear stress method with 3 fibers model composite. The surface condition of the fiber and crack propagation at the interface between the fiber and the matrix are observed by scanning electron microscope (SEM). Alkali treatment on Typha spp. fiber can make the fiber surface coarser, thus increasing the value of interfacial fracture toughness and interfacial shear strength. Typha spp. fiber/epoxy has a higher interfacial fracture value than that of Typha spp. fiber/PLLA. Interfacial fracture toughness on Typha spp. fiber/PLLA and Typha spp. fiber/epoxy composite model specimens were influenced by the matrix length, fiber spacing, fiber diameter and bonding area. Furthermore, the interfacial fracture toughness and the interfacial fracture shear stress of the composite model increased with the increasing duration of the surface treatment.EDPI, 2019年06月, Materials (17pages), 12(14) (14), 2225, 英語, 国際誌[査読有り]研究論文(学術雑誌)
- 高輝度光科学研究センター, 2019年03月, 平成30年度Spring-8放射光施設横断産業利用課題.一般課題(産業分野)実施報告書, 日本語[査読有り][招待有り]研究論文(大学,研究機関等紀要)
- 日本非破壊検査協会, 2019年03月, 非破壊検査, 68(3) (3), 132 - 136, 日本語
In recent years, numerous damages in the RC slabs of road bridges due to increasing traffic volume, over-weight vehicles and salt damage caused by anti-freezing agent have been reported. Therefore, development of an effective non-destructive inspection method for detecting such damages in concrete slabs beneath asphalt pavement is essential. Among various methods, the infrared thermography method enables non-contact and traveling investigations to be conducted for wide area of road bridges in a short time. Using this advantage, we developed a detection system for damages in RC slabs beneath asphalt pavement utilizing infrared thermography. The developed system can prevent degradation of thermography data based on extended exposure time by overlapped capturing of ten images from high-speed moving vehicles and can automatically generate a highly comprehensive panoramic image. Visible images of the road surface can also be acquired at the same time, making it possible to more accurately determine obstacles in the RC slabs beneath asphalt pavement.
[査読有り]研究論文(学術雑誌) - 高輝度光科学研究センター, 2019年03月, 平成30年度Spring-8放射光施設横断産業利用課題.一般課題(産業分野)実施報告書, 日本語[査読有り][招待有り]研究論文(大学,研究機関等紀要)
- The flaking failure in rolling contact fatigue (RCF) has been believed to originate from nonmetallic inclusions located beneath the surface. With conventional microscopies, however, damage process in the internal region of materials could not be observed, then they were observed by computed laminography using ultra-bright synchrotron radiation X-ray, and the effects of the shape and the orientation on the RCF crack initiation and propagation behaviors were examined. In every case, cracks were first initiated from surface inclusion, and they propagated to the surface and the thickness direction. After the crack reached a critical distance, horizontal cracks were formed from the vertical cracks, where the normal of the horizontal cracks were perpendicular to the surface, and those of the vertical cracks were parallel to the surface. However, the propagation direction just after the initiation from inclusions depended on the orientation of inclusions relative to the rolling direction.Materials Science and Technology, 2019年, MS and T 2019 - Materials Science and Technology 2019, 822 - 829, 英語研究論文(国際会議プロシーディングス)
- 一般社団法人 日本機械学会, 2019年, 関西支部講演会講演論文集, 2019(0) (0), 209 - 209, 日本語
The dissipated energy was measured for FSW and FSW with polishing during fatigue tests and the relationship between fatigue strength and dissipated energy was investigated. Compared with FSW, the dissipated energy of FSW with polishing was lowered due to surface roughness of the welding zone. The increase in dissipated energy of FSW was related to fatigue strength.
- 一般社団法人 日本機械学会, 2019年, 年次大会, 2019(0) (0), J40135P, 日本語
When the material is subjected to cyclic load, temperature changes due to the thermoelastic effect is observed. The stress distribution can be evaluated by thermoelastic temperature change. Temperature change due to the energy dissipation caused by plastic slip deformation is measured by infrared camera. Anticorrosion coating is applied to a lot of mechanical structures. When the temperature change is measured over the coating, thermoelastic stress analysis and dissipated energy measurement are affected by the anticorrosion coating. In this study, the effect of the anticorrosion coating on the temperature measurement over the coating was investigated by numerical simulation and experiment. It was found from numerical simulation and experiments that the ratio of the temperature amplitude on coating to that on the metal surface decreases with increasing in load frequency, and the time delay of the temperature change on the coating relative to the metal surface increases with increasing in load frequency.
- 一般社団法人 日本機械学会, 2019年, M&M材料力学カンファレンス, 2019(0) (0), OS1203, 日本語
In steel structures, fatigue cracks may initiate due to long-term use or unexpected excessive loads. A thermoelastic temperature change based on thermoelastic effects is measured under dynamic loading. It is possible to evaluate stresses on the wide surface of structure, and the stress intensity factor can be calculated from the obtained stress distribution. For the evaluation of stress intensity factor, crack length is required. It is difficult to identify the location of crack tip from infrared image. The fake temperature change due to the rigid displacement of cracked body is measured. To improve the accuracy of thermoelastic stress measurement and crack tip identification, the motion compensation using an optical camera and the measurement of the energy dissipation at crack tip were applied to the evaluation of stress intensity factor. It was found that the fake temperature change can be removed by the motion compensation using DIC with an optical camera, and the size and location of highly dissipation energy area coincide with the plastic zone at crack tip.
- 一般社団法人 日本機械学会, 2019年, M&M材料力学カンファレンス, 2019(0) (0), OS1207, 日本語
In recent years, the solution for challenge that car body weight reduction compatible with rigidity improvement is required. Weld bonding is one of the methods to solve the problem. This method is based on a combination of bonding at the car body and spot welding, and this makes it possible to improve rigidity of the body structure even if the thickness of steel plate is reduced. For applying weld bond method, inspection of the adhesion region is important. Therefore, developing a new nondestructive testing technique which enables in-line inspection for all car bodies is required. In this research, we examined the applicability of the active pulse heating infrared thermography for the inspection of adhesion region. We tested two kinds of specimen in this research. One is a hat type specimen which was simulated car body frame parts, the other is a plate specimen for examining the effect of thickness of steel sheet on the accuracy of adhesion region identification. Further for simulating the actual in-line production process, applicability of the active infrared thermography was tested for plate specimen heated to high temperature. Experimental results show the applicability of the proposed technique for the in-line nondestructive testing for car body frame parts under production process.
- 一般社団法人 日本機械学会, 2019年, M&M材料力学カンファレンス, 2019(0) (0), OS1208, 日本語
With the retirement of skilled workers and the aging deterioration of gas plant facilities, interest in the development of automated and remote gas detection methods is increasing. Therefore, a gas leak detection method using infrared camera has been proposed. Invisible gas can be detected from spectrum infrared absorption of the target gas and the emitted infrared ray from the gas itself. The piping of a gas plant is very complicated, so it is very useful that the gas leak source can be identified. In this study, the gas-leak source identification is performed by the inverse problem analysis using the gas-signal image created based on the infrared measurement data. The gas-signal image is obtained by applying a data processing scheme that excludes background temperature change and high frequency noise, and it extracts only the temperature change due to the influence of gas from infrared measurement data. The least residual method, one of the typical inverse problem analysis methods, is employed to estimate the location of the gas leak source from the sequential infrared images of the gas cloud distribution and flow. It was found from numerical simulation and laboratory experiments that it was possible to estimate the location of the gas leak source, even when the leak source was hidden by obstacles such as piping in infrared images.
- 2019年, Yosetsu Gakkai Shi/Journal of the Japan Welding Society, 88(3) (3), 160 - 164[査読有り]研究論文(学術雑誌)
- © The Society for Experimental Mechanics, Inc. 2019. The fatigue limit estimation method based on the dissipated energy measurement was applied to the single bead-on-plate weld. The stair-case-like stress level test was conducted to the bead-on-plate specimen. The local concentration of dissipated energy was observed in the weld toe. The change in dissipated energy at this local high dissipated energy point showed sharp increase from the certain stress amplitude, and this stress amplitude coincided with the fatigue limit for the bead-on-plate specimen obtained from S-N curves.SEM, 2019年, Conference Proceedings of the Society for Experimental Mechanics Series, 7, 119 - 123, 英語[査読有り]研究論文(国際会議プロシーディングス)
- © The Society for Experimental Mechanics, Inc. 2019. Short carbon fiber composite materials are receiving a lot of attentions because of their excellent moldability and productivity, however they show complicated behaviors in fatigue fracture due to the random fibers orientation. In this study, thermoelastic stress analysis (TSA) using an infrared thermography was applied to the evaluation of fatigue damage in short carbon fiber composites. Second harmonic component of thermoelastic temperature change that is obtained by lock-in processing based on double-frequency against loading frequency was conducted to identify the turbulence in thermoelastic waveform due to fatigue damage evolution. It was found that the portions showing high second harmonic component values coincided with the portions where delamination damages were detected.SEM, 2019年, Conference Proceedings of the Society for Experimental Mechanics Series, 7, 109 - 113, 英語[査読有り]研究論文(国際会議プロシーディングス)
- 日本材料学会, 2018年12月, 材料, 67(12) (12), 1036 - 1041, 日本語[査読有り]研究論文(学術雑誌)
- 高輝度光科学研究センター, 2018年09月, 平成29年度 Spring-8産業新分野支援課題・一般課題(産業分野)実施報告書, 209 - 212, 日本語[査読有り][招待有り]研究論文(大学,研究機関等紀要)
- 高輝度光科学研究センター, 2018年09月, 平成29年度 Spring-8産業新分野支援課題・一般課題(産業分野)実施報告書, pp.60-64, 2018, 60 - 64, 日本語[査読有り][招待有り]研究論文(大学,研究機関等紀要)
- 高輝度光科学研究センター, 2018年09月, 平成29年度 Spring-8産業新分野支援課題・一般課題(産業分野)実施報告書, pp.121-124, 2018, 121 - 124, 日本語[査読有り][招待有り]研究論文(大学,研究機関等紀要)
- JSNDI and ASNT, 2018年07月, Proc. Of the Sixth Japan-US NDT Symposium Emerging NDE Capabilities for a Safer World, Paper No. 501044, 英語Fatigue crack evaluation for steel bridge maintenance by infrared thermography研究論文(国際会議プロシーディングス)
- EDP Sciences, 2018年06月, MATEC Web of Conferences, 165(11002) (11002), 1 - 8, 英語[査読有り]研究論文(国際会議プロシーディングス)
- MDPI, 2018年06月, Proceedings, 2(380) (380), 1 - 7, 英語[査読有り]研究論文(国際会議プロシーディングス)
- The flaking failure in rolling contact fatigue (RCF) results from crack initiation and propagation has been believed to originate from non-metallic inclusions located beneath the surface. With conventional microscopies, however, damage process in the internal region of materials could not be observed, then RCF crack initiation and propagation behaviours were observed by using synchrotron radiation computed laminography (SRCL) in the brightest synchrotron facility in Japan, and the effect of the inclusion orientation on the RCF property was examined. In our previous studies, crack initiation and propagation behaviours caused by extended MnS inclusions distributed in depth or transverse (width) direction was observed by the SRCL. In the present study, the fracture mechanism under RCF was discussed on specimens with MnS inclusions distributed in the rolling direction. As a result, vertical cracks were initiated on the surface, parallel to the ball-rolling direction in specimens. The crack propagation direction was then changed perpendicular to the rolling direction. Thereafter, similar with our previous studies, vertical cracks caused the horizontal cracks beneath the surface, when the vertical cracks reached to a critical length. The ratio of the vertical crack initiation life to the flaking life was higher than specimens with other inclusion orientation.EDP Sciences, 2018年05月, MATEC Web of Conferences, 165, 英語[査読有り]研究論文(国際会議プロシーディングス)
- Heavy-duty anticorrosion coating with multiple-layered paints is applied to long-span steel bridge members on the sea. By aging deterioration, the coating is worn from surface year by year. Appropriate repainting programs should be adopted for the maintenance of the bridges according to the evaluation of wear extent. In this study a new nondestructive evaluation technique using short wavelength infrared (SWIR) camera, that enables us to easily detect the wear loss of surface fluororesin coating layer, is developed based on the difference in spectral absorptance between surface fluororesin coating and inner-layer epoxy resin coating.SPIE, 2018年05月, Proc. SPIE, 10661, paper#106610T, 英語[査読有り]研究論文(国際会議プロシーディングス)
- 高輝度光科学研究センター, 2018年04月, 平成29年度 Spring-8産業新分野支援課題・一般課題(産業分野)実施報告書, 70 - 73, 日本語[査読有り][招待有り]研究論文(大学,研究機関等紀要)
- 高輝度光科学研究センター, 2018年04月, 平成29年度 Spring-8産業新分野支援課題・一般課題(産業分野)実施報告書, 108 - 110, 日本語[査読有り][招待有り]研究論文(大学,研究機関等紀要)
- 一般社団法人 日本機械学会, 2018年, M&M材料力学カンファレンス, 2018(0) (0), OS0405, 日本語
In order to maintain the safety of infrastructures such as steel bridges, it is important to detect fatigue cracks by nondestructive evaluation, to evaluate crack propagation rate, and to verify the effectiveness of crack repair.One of the effective non-destructive evaluation methods for these purposes is thermoelastic stress measurement by infrared thermography.In this method, stress distribution is measured based on the temperature fluctuation due to the thermoelastic effect. It enables us to conduct remote nondestructive and noncontact measurement of stress distribution.In this study, a plate bending fatigue test was carried out using specimens simulating steel members with fatigue cracks in actual bridges. The relationship between crack propagation rate and stress intensity factor range were obtained from measured stress data. It is found that obtained relation agrees well with the Paris law. Based on the experimental result, the reduction of crack propagation rate by the repair works in the actual bridge is estimated.
- 一般社団法人 日本機械学会, 2018年, M&M材料力学カンファレンス, 2018(0) (0), OS0401, 日本語
Nondestructive inspection methods using infrared thermography for detecting delamination of surface finishing material such as tiles or mortal on concrete structures have been employed for a long time due to their advantages of effectiveness being able to measure a wide area at once. However in the case of using infrared thermography having a sensitivity in 8-14μm spectrum band used in ordinary building inspection, there is a problem that infrared images are influenced by the reflection of surrounding infrared emitting sources such as solar radiation or high temperature heat sources. In this study, infrared ray in 5-8μm spectrum band is utilized its low reflectivity on shiny white tile surface and high spectrum absorbance of atmosphere for avoiding the reflection. Infrared thermography having a sensitivity in 5-8μm spectrum band is developed based on microbolometer infrared camera to make it possible to reduce the reflection on building surface. We measure the temperature distribution on the surface of the building using the infrared cameras having sensitivity in 5-8μm and 8-14μm spectrum bands. From experimental results, we found that 5-8μm spectrum band infrared camera has the ability of reducing the influence of solar reflection as well as the defect detectability.
- 一般社団法人 日本機械学会, 2018年, M&M材料力学カンファレンス, 2018(0) (0), OS0402, 日本語
Heavy anticorrosion paint is applied on the surface of steel bridges for protecting corrosion. The heavy anticorrosion coating is composed of multiple paint layers such as zinc rich paint undercoating for electric corrosion protection, epoxy resin middle coat paint for protecting the zinc rich paint, and weather proof fluorine resin top coat. In the maintenance program of steel bridge anticorrosion coating, it is important to decide the timing of repainting repair, and in general the timing is set when the weather proof fluorine resin top coat is lost. However it is difficult to detect the loss of top coat by visual testing. Therefore it is beneficial for the preventive maintenance to determine the wear of top coat quantitatively before the top coat is completely lost. In this study, experiments were conducted with the aim of quantitative estimation of the degree of abrasion of the top coat thickness. It was found that it is possible to estimate the topcoat thickness based on the infrared luminance value.
- 一般社団法人 日本機械学会, 2018年, M&M材料力学カンファレンス, 2018(0) (0), PS16, 日本語
The fatigue limit estimation based on the dissipated energy measurement has been developed and the applicability of this technique for some steels has been investigated. However, there have been no reports on high-strength materials such as Ni-base high-strength alloys. Establishment of a simple and rapid fatigue limit estimation method for materials used under high load environment like this material is expected to greatly contribute to improvement of machine safety and reliability. In this study, we investigated the applicability of fatigue limit estimation method based on dissipated energy measurement for Ni-based alloy Inconel718.
- Carbon fiber-reinforced plastic (CFRP) is widely used for structural members of transportation vehicles such as automobile, aircraft, or spacecraft, utilizing its excellent specific strength and specific rigidity in contrast with the metal. Short carbon fiber composite materials are receiving a lot of attentions because of their excellent moldability and productivity, however they show complicated behaviors in fatigue fracture due to the random fibers orientation. In this study, thermoelastic stress analysis (TSA) using an infrared thermography was applied to evaluate fatigue damage in short carbon fiber composites. The distribution of the thermoelastic temperature change was measured during the fatigue test, as well as the phase difference between the thermoelastic temperature change and applied loading signal. Evolution of fatigue damage was detected from thedistribution of thermoelastic temperature change according to the thermoelastic damage analysis(TDA) procedure. It was also found that fatigue damage evolution was more clearly detected than before by the newly developed thermoelastic phase damage analysis (TPDA) in which damaged area was emphasized in the differential phase delay images utilizing the property that carbon fiber shows opposite phase thermoelastic temperature change.MDPI AG, 2017年12月, Sensors (Switzerland), 17(12) (12), 2824 - 2824, 英語, 国際誌[査読有り]研究論文(学術雑誌)
- Since rolling contact fatigue (RCF) is known to be affected by non-metallic inclusions, the RCF crack initiation and propagation mechanisms in high-strength steels were observed using ultrabright synchrotron radiation laminography. The material of the sample was a high-carbon chromium bearing steel, which intentionally contained a high concentration of sulfur to enable the observation of crack initiation from MnS inclusions. To conduct an RCF test nearby the experimental hatch of a beam line of a synchrotron radiation facility, a special RCF testing machine was developed. Fatigue tests were interrupted to conduct laminography. The fatigue life for flaking depended on the length, width, and orientation of inclusions. For every length and orientation of inclusions, vertical cracks, whose faces were perpendicular to the rolling direction, first appeared, then horizontal cracks, whose faces were parallel to the sample surface, were formed after the vertical cracks reached a critical length. The initiation life of the vertical cracks and horizontal cracks depended on the length, width, and orientation of the MnS inclusions. The depth of horizontal crack initiation site, however, was almost independent of these parameters. The mechanism of the flaking process, which was directly observed by laminography using synchrotron radiation, was completely different from that previously supposed from observations by conventional microscopy. (C) 2017 Elsevier Ltd. All rights reserved.PERGAMON-ELSEVIER SCIENCE LTD, 2017年10月, ENGINEERING FRACTURE MECHANICS, 183, 180 - 189, 英語[査読有り]研究論文(学術雑誌)
- Ageing steel bridges suffer fatigue cracks thereby necessitating immediate inspection, structural integrity evaluation or repair in the life cycle of steel bridges. We propose non-destructive evaluation techniques employing infrared thermography enabling us to remotely inspect the fatigue cracks in steel bridges and evaluate the structural integrity on the basis of thermoelastic stress measurement. This study presents a structural integrity assessment of steel bridges using remote measurement of the stress field around the fatigue cracks. We focus upon experimental results confirming reduction in the severity of the stress distribution around the fatigue cracks after the repair or reinforcement of members in steel bridges. (C) 2017 Elsevier Ltd. All rights reserved.PERGAMON-ELSEVIER SCIENCE LTD, 2017年10月, ENGINEERING FRACTURE MECHANICS, 183, 1 - 12, 英語[査読有り]研究論文(学術雑誌)
- Elsevier, 2017年10月, Procedia Structural Integrity, 7, 468 - 475, 英語[査読有り]研究論文(学術雑誌)
- 高輝度光科学研究センター, 2017年09月, 2016B期産業新分野支援課題・一般課題(産業分野)実施報告書, 82 - 85, 日本語[査読有り][招待有り]研究論文(大学,研究機関等紀要)
- 高輝度光科学研究センター, 2017年09月, 2016B期産業新分野支援課題・一般課題(産業分野)実施報告書, 135 - 138, 日本語[査読有り][招待有り]研究論文(大学,研究機関等紀要)
- Fatigue crack propagation in aging steel bridges has become a serious problem. Nondestructive evaluation of fatigue damage propagation is necessary to ensure safety and to estimate the remaining life of the bridges. Conventionally employed nondestructive testing (NDT) techniques such as visual testing, magnetic particle testing and ultrasonic testing are time-and labor- consuming techniques, further these NDT techniques cannot be used to directly evaluate the remaining strength of the bridges. Thermoelastic stress analysis (TSA) using infrared thermography has been widely used as an effective full-field experimental stress measurement technique. In this study, TSA was applied for on-site measurement of stress distributions around fatigue cracks, and the future crack propagation behavior was estimated by the fracture mechanics approach. Experimental studies were conducted for laboratory specimens which modeled a part of welded structure in steel bridges. The stress intensity factors were calculated from stress distributions measured by TSA technique. Relationship between stress intensity factor ranges and crack propagation rates was obtained. It is found that the obtained relationship shows a good correspondence with the Paris law. Further TSA technique was applied to evaluate the effectiveness of repair or reinforcement for defective portions. Severity reduction in stress distribution around the fatigue crack after treatment was confirmed for actual steel bridge members by TSA. Crack propagation rate was estimated from the stress intensity factor calculated from on-site stress measurement data. As the result, 55% reduction in crack propagation rate was ascertained indicating the positive effect of the crack repair. (c) 2017 The Authors. Published by Elsevier B.V.Elsevier, 2017年09月, Procedia Structural Integrity, 5, 1370 - 1376, 英語[査読有り]研究論文(国際会議プロシーディングス)
- AITA, 2017年09月, Abstract Booklet of the 14th edition of the International Workshop on Advanced Infrared Technology and Applications, AITA 2017, 183 - 186, 英語Effect of mean stress on phase difference of dissipated energy[査読有り]研究論文(国際会議プロシーディングス)
- AITA, 2017年09月, Abstract Booklet of the 14th edition of the International Workshop on Advanced Infrared Technology and Applications, AITA 2017, 168 - 171, 英語Detection of fatigue damage in short carbon fiber reinforced plastics using thermoelasticity[査読有り]研究論文(国際会議プロシーディングス)
- 日本材料学会, 2017年08月, 材料, 66(8) (8), 621 - 626, 日本語[査読有り][招待有り]
- In this paper, a technique for improving the accuracy of a dissipated energy measurement based on the phase information-called the phase 2f lock-in infrared method-is proposed. In the conventional 2f lock-in infrared method, the dissipated energy is obtained as the double frequency component of the measured temperature change. In this work, a phase analysis of the double frequency component has been conducted. It is found that the double frequency component includes the influence of the energy dissipation and harmonic vibration of the fatigue testing machine, and the phase difference between the thermoelastic temperature change and the double frequency component is a specific value. The phase 2f lock-in method utilizes a specific phase of the dissipated energy and is effective for removing the noise component such as the thermoelastic temperature change due to the harmonic vibration of fatigue testing machine. This method provides an improvement in the accuracy of the fatigue-limit estimate and the detection of future crack initiation points based on the dissipated energy.IOP PUBLISHING LTD, 2017年04月, MEASUREMENT SCIENCE AND TECHNOLOGY, 28(4) (4), 英語[査読有り]研究論文(学術雑誌)
- Crack initiation and propagation behaviors under rolling contact fatigue observed by laminography using synchrotron radiation X-rayThe rolling contact fatigue (RCF) crack initiation and propagation behaviors in high strength steels were observed using ultra-bright synchrotron radiation laminography. The fatigue life for flaking depended on the length, width, and orientation of inclusions. In either case, vertical cracks, whose faces were perpendicular to the rolling direction, were first appeared, then horizontal cracks, those faces were parallel to the sample surface were formed after the vertical cracks reached a critical length. The initiation life of the vertical cracks and horizontal cracks depended on the length, width, and orientation of the MnS inclusions. The depth of the horizontal crack initiation, however, was almost independent of these parameters.International Conference on Fracture, 2017年, ICF 2017 - 14th International Conference on Fracture, 1, 191 - 192, 英語研究論文(国際会議プロシーディングス)
- 一般社団法人 日本機械学会, 2017年, 日本機械学会論文集, 日本語
The initiation and growth of internal small fatigue cracks with around ten or several dozen μm in Ti-6Al-4V were nondestructively examined by using synchrotron radiation μCT at the large synchrotron radiation facility SPring-8. Lots of grain-sized internal cracks were observed roughly evenly in the observation volume in the specimen; in contrast, only one surface crack was detected. The initiation lives of the internal cracks were widely different for each crack and had no significant correlation with the crack initiation site nor the initial crack size. The internal cracks propagated microstructure-sensitively with several crack deflections, and the growth rates were very small, less than 10-10 m/cycle. The crack growth rates just after facet formations showed large variability and had no apparent relationship with the crack initiation life nor the initial crack size. This variability can likely be attributed to microstructural inhomogeneities around the crack initiation facets. The estimated facet formation rate indicated that most facets formed rapidly compared with the following internal crack growth rate.
- 一般社団法人 日本機械学会, 2017年, M&M材料力学カンファレンス, 2017(0) (0), OS0210, 日本語
The fatigue limit estimation based on the dissipated energy measurement has been developed and the applicability of this technique for some steels has been investigated. The coating was applied to the component of the industrial structures. It is useful to measure the dissipated energy and apply the fatigue limit estimation for the industrial component without removing the coating. In this study, the effect of the coating on the dissipated energy measurement was investigated. The black body treatment is required for the infrared thermography measurement because of the metallic reflection. The sanding of coating is enough for the measurement of dissipated energy without the black body treatment of the coating. The dissipated energy measurement in the stair case like stress level test was applied to the specimen having various coating thickness. It was found that the temperature change due to the dissipated energy can be obtained even though the temperature change was attenuated by the coating with 200μm thickness.
- 一般社団法人 日本機械学会, 2017年, 関西支部講演会講演論文集, 2017(0) (0), P080, 日本語
- A three dimensional grain mapping technique for polycrystalline materials, called X-ray diffraction contrast tomography (DCT), was developed at SPring-8, which is the brightest synchrotron radiation facility in Japan. The developed technique was applied to a commercially pure iron and austenitic stainless steel. The shape and location of grains could be determined by DCT using the apparatus in a beam line of SPring-8. To evaluate the dislocation structure in fatigue, the total misorientation of individual grains was measured by DCT. The average value of the total misorientation over one sample was increased with the number of cycles. In a grain, the change of the total misorientation was largest for primary slip plane. For austenitic stainless steel (fcc), the change of the total misorientation in fatigue was larger for planes with larger Schmid factor, while it was not depended on the Schmid factor for commercially pure iron (bcc). This different behavior must come from planer slip in fcc structure and wavy slip in bcc structure.Trans Tech Publications Ltd, 2017年, Materials Science Forum, 879, 1355 - 1360, 英語[査読有り]研究論文(国際会議プロシーディングス)
- A three-dimensional grain mapping technique for polycrystalline materials, called X-ray diffraction contrast tomography (DCT), was developed at SPring-8, which is the brightest synchrotron radiation facility in Japan. The developed technique was applied to an austenitic stainless steel. The shape and location of grains could be determined by DCT using the apparatus in a beam line of SPring-8. To evaluate the dislocation structure in fatigue, the total misorientation of individual grains was measured by DCT. The average value of the total misorientation over one sample was increased with the number of cycles. In a grain, the change of the total misorientation was largest for the primary slip plane. The maximum change of the total misorientation in fatigue was larger for planes with larger Schmid factor, and the first fatigue crack initiation was occurred in a grain, which had the greatest change of the total misorientation. Copyright (C) 2017 The Authors. Published by Elsevier B.V.ELSEVIER SCIENCE BV, 2017年, XXIV ITALIAN GROUP OF FRACTURE CONFERENCE, 2017, 3, 402 - 410, 英語[査読有り]研究論文(国際会議プロシーディングス)
- Fatigue limit estimation using infrared thermography has recently received attention as a method for reducing the time required for product design. In this study, the applicability of a method based on mean temperature and dissipated energy measurements was experimentally investigated on a titanium alloy fatigue plate specimens were fabricated from the titanium alloy Ti-6Al-4V ELI. The fatigue limit of these specimens obtained from conventional fatigue testing was found to be 620 MPa. The estimated fatigue limit obtained from mean temperature measurements was found to be 600 MPa, although estimating the fatigue limit using dissipated energy measurements was difficult because little significant change in dissipated energy values with the stress amplitude was observed. These tendencies are probably attributed to the crystal structure displaying different deformation properties and high vibration absorption properties. The resonance components from the fatigue testing instruments (noise components) were calculated from the frequency analysis of the time-series temperature fluctuation data measured by infrared thermography. The increase in the dissipated energy values (with the noise components subtracted) against the stress amplitude changed at a certain stress amplitude and the fatigue limit could be estimated to be 565 MPa. Therefore, the relative error between the fatigue limit value obtained from conventional fatigue testing and the estimated values was within 10%. The fatigue limit could be estimated more accurately by considering the influence of different deformation properties between tensile and compressive loading due to the crystal structure differences in the dissipated energy measurement.SPIE, 2017年, Proceedings of SPIE - The International Society for Optical Engineering, 10214, 102140J - 1, 英語[査読有り]研究論文(国際会議プロシーディングス)
- Carbon fiber-reinforced plastic (CFRP) is widely used for structural members of transportation vehicles such as automobile, aircraft or spacecraft, utilizing its excellent specific strength and specific rigidity in contrast with the metal. Short carbon fiber composite materials are receiving a lot of attentions because of their excellent moldability and productivity, however they show complicated behaviors in fatigue fracture due to the random fibers orientation. In this study, thermoelastic stress analysis (TSA) using an infrared thermography was applied to the evaluation of fatigue damage in short carbon fiber composites. The distributions of the thermoelastic temperature change was measured during the fatigue test, as well as the phase difference between the thermoelastic temperature change and applied loading signal. Evolution of fatigue damages was detected from distributions of thermoelastic temperature change according to the thermoelastic damage analysis (TDA) procedure. It was also found that fatigue damage evolution was clearly detected than ever by the newly developed thermoelastic phase damage analysis (TPDA) in which damaged area was emphasized in the differential phase delay images utilizing the nature that carbon fiber show opposite phase thermoelastic temperature change.SPIE, 2017年, Proceedings of SPIE - The International Society for Optical Engineering, 10214, 102140M - 1, 英語[査読有り]研究論文(国際会議プロシーディングス)
- 2017年, 3RD INTERNATIONAL SYMPOSIUM ON FATIGUE DESIGN AND MATERIAL DEFECTS (FDMD 2017), 7, 468 - 475[査読有り]
- The objective of the present paper is to clarify the effect of shapes of circular hole defects, orientated perpendicular to the surface, on rolling contact fatigue (RCF) crack initiation and propagation in high strength steel. RCF test and synchrotron radiation micro computed tomography (SR micro CT) imaging were conducted. In the case of a 15-mu m-diameter defect, the number of cycles of rolling contact to flaking occurring (flaking life) decreased with increasing defect length. In a comparison of the CT image and the SEM view, the shapes of defects and the locations of the horizontal cracks were almost the same respectively. The mechanism of RCF crack propagation was discussed by finite element (FE) analysis. Defects led to higher tensile residual stress than that without defects in the region where the defect exists. The shear stress range at 0.1 mm in depth on the middle line of the defect and the range of mode II stress intensity factor at the bottom of a vertical crack increased with increasing defect length. In the case of a defect 50 gm in diameter, defect length does not affect flaking life. The reason for this is probably that the horizontal cracks form and propagate before vertical cracks grow to an effective size. (C) 2016 Elsevier Ltd. All rights reserved.ELSEVIER SCI LTD, 2016年11月, INTERNATIONAL JOURNAL OF FATIGUE, 92, 507 - 516, 英語[査読有り][招待有り]研究論文(学術雑誌)
- 高輝度光科学研究センター, 2016年09月, 平成27年度 Spring-8産業新分野支援課題・一般課題(産業分野)実施報告書, 43 - 46, 日本語放射光X線ラミノグラフィによる水平方向介在物配向材における転動疲労はく離起点介在物の特定-介在物形状・分布の評価[査読有り][招待有り]研究論文(大学,研究機関等紀要)
- 高輝度光科学研究センター, 2016年09月, 平成27年度 Spring-8産業新分野支援課題・一般課題(産業分野)実施報告書, 132 - 133, 日本語回折コントラストトモグラフィを用いた疲労における結晶ミスオリエンテーション挙動のその場観察[査読有り][招待有り]研究論文(大学,研究機関等紀要)
- 2016年09月, Proc. of Asia-Pacific Conference on Fracture and Strength 2016, 223 - 224, 英語Relationship between dissipated energy and growth behavior of slip bands in austenitic stainless steel[査読有り]研究論文(国際会議プロシーディングス)
- 2016年09月, Proc. of Asia-Pacific Conference on Fracture and Strength 2016, 225 - 226, 英語Influence of extension tubes on thermoelastic temperature measurement with infrared thermography[査読有り]研究論文(国際会議プロシーディングス)
- 2016年07月, International Journal of Fatigue, 93, 397 - 405, 英語Non-destructive observation of internal fatigue crack growth in Ti-6Al-4V by using synchrotron radiation μCT imaging[査読有り]研究論文(学術雑誌)
- 高輝度光科学研究センター, 2016年03月, 平成26年度 SPring-8 産業新分野支援課題・一般課題(産業分野)実施報告書(2015A), 24 - 27, 日本語放射光X線ラミノグラフィによる転動疲労き裂発生および進展挙動のその場観察-異なる配向形態観察の試行[査読有り][招待有り]研究論文(大学,研究機関等紀要)
- 高輝度光科学研究センター, 2016年03月, 平成26年度 SPring-8 産業新分野支援課題・一般課題(産業分野)実施報告書(2015A), 124 - 125, 日本語回折コントラストトモグラフィを用いたき裂発生過程の結晶ミスオリエンテーションの観察[査読有り][招待有り]研究論文(大学,研究機関等紀要)
- The initial process of internal fracture in Ti-6Al-4V was non-destructively observed by synchrotron radiation μCT imaging to clarify the crack initiation and initial growth behavior in very high cycle fatigue. As a result, a number of cracks were detected all over the observation volume. The internal crack firstly initiated at around 5.0 × 106 cycles, however, the initiation lives of these cracks varied widely. The just initiated crack propagated microstructure-sensitively at significantly low growth rate. Some cracks initiated so early and propagated so slowly, but others initiated so lately and propagated so rapidly. As above, the crack initiation sites and lives widely varied, and the crack growth rate just after the initiation has a large scatter. These results let us to conclude that the local microstructural conditions and the effect of environment around the crack are indispensable factors to fully understand the initial process of internal fracture in very high cycle fatigue.一般社団法人 日本機械学会, 2016年, M&M材料力学カンファレンス, 2016, OS02-26, 日本語
- Inclusion orientation effect on rolling contact fatigue crack paths observed by laminography using synchrotron radiation x-raySince rolling contact fatigue (RCF) property are known to be influenced by non-metallic inclusions, the RCF crack initiation and propagation mechanisms in high strength steels were observed using ultra-bright synchrotron radiation laminography. The material of the sample and ball were high carbon-chromium bearing steel. The material had intentionally contains a high concentration of sulfur to enable the observation of crack initiation from MnS inclusions. To conduct rolling contact fatigue test for thin plate nearby the experimental hatch of a beam-line of the synchrotron radiation facility, a special RCF test machine was developed. Fatigue tests were interrupted to conduct laminography. The fatigue life for flaking depended on the length, width, and orientation of inclusions. In either case, vertical cracks, whose faces were perpendicular to the rolling direction, were first appeared, then horizontal cracks, those faces were parallel to the sample surface were formed after the vertical cracks reached a critical length. The initiation life of the vertical cracks and horizontal cracks depended on the length, width, and orientation of the MnS inclusions. The depth of the horizontal crack initiation, however, was almost independent of these parameters. These mechanism of flaking process, which was directly observed by laminography using synchrotron radiation, was completely different from that previously supposed from the surface observations by conventional microscopies.Association for Iron and Steel Technology, AISTECH, 2016年, Materials Science and Technology Conference and Exhibition 2016, MS and T 2016, 2, 975 - 982, 英語研究論文(国際会議プロシーディングス)
- Recently there are concerns about maintenance of aging infrastructures built in the period of high economic growth. In order to maintain the safety of the steel structures, periodic inspection and proper repair are required. In addition, it is also important to confirm the effectiveness of the repair. Thermoelastic stress measurement using infrared thermography is one of the effective non-destructive evaluation techniques. In the present study, thermoelastic stress measurement is conducted for cracked members in the cable-stayed bridge in the Seto Ohashi Bridge, for the verification of repair effect. Several repair methods were investigated by experimental studies at the site. Effectiveness of the employed repair methods, i.e., the reduction of the applied stress, were verified by the thermoelastic stress measurement.一般社団法人 日本機械学会, 2016年, M&M材料力学カンファレンス, 2016, PS-32, 日本語
- 高輝度光科学研究センター, 2016年, 平成27年度 Spring-8産業新分野支援課題・一般課題(産業分野)実施報告書, 日本語放射光X線ラミノグラフィによる転動疲労き裂発生および進展挙動のその場観察ー異なる配向形態観察の試行ー[査読有り]研究論文(大学,研究機関等紀要)
- 高輝度光科学研究センター, 2016年, 平成27年度 Spring-8産業新分野支援課題・一般課題(産業分野)実施報告書, 日本語回折コントラストトモグラフィを用いた疲労き裂発生過程の結晶ミスオリエンテーションの観察[査読有り]研究論文(大学,研究機関等紀要)
- The purpose of this study is to develop a method for detecting small internal fatigue cracks in Ti-6Al-4V by using synchrotron radiation provided at SPring-8. An electro-hydraulic fatigue testing machine was carried into the facility and a combination of uniaxial fatigue tests and micro computed tomography (μCT) imagings were conducted. The small specimen without size effect was newly designed for μCT imaging. The conditions of the fatigue tests were determined to observe internal crack initiations within the available time at the facility. To obtain a clear and accurate image of internal cracks, several important parameters for μCT imaging such as the crack opening load, the distance between detector and specimen, were optimized. As a result, multiple internal fatigue cracks sized around 30 μm or below were successfully detected.日本機械学会, 2016年, Bulletin of the JSME, Mechanical Engineering Letters, 2(16) (16), 00233 - 00233-16-00233, 英語[査読有り]研究論文(学術雑誌)
- A three dimensional grain mapping technique for polycrystalline materials, called X-ray diffraction contrast tomography (DOT), was developed at SPring-8 (Super Photon ring - 8 GeV), which is the brightest synchrotron radiation facility in Japan, and the measurement conditions and data acquisition procedure are discussed. The developed technique was applied to a commercially pure aluminum, commercially pure iron, and austenitic stainless steel. The shape and location of grains could be determined by Da using the apparatus in a bending beam line of SPring-8. To evaluate the dislocation structure in tensile tests and fatigue tests, the rotation angle spread of individual grains was measured. The rotation angle spread is caused by mosaicity, which is related to the dislocation structure in a grain. The rotation angle spread was found to increase with increasing plastic strain. Fatigue damage could also be evaluated from the rotation angle spread obtained by Da measurement. (C) 2015 Elsevier Ltd. All rights reserved.ELSEVIER SCI LTD, 2016年01月, INTERNATIONAL JOURNAL OF FATIGUE, 82, 247 - 255, 英語[査読有り]研究論文(学術雑誌)
- Nondestructive testing (NDT) techniques using pulse heating infrared thermography and terahertz (THz) imaging were developed for detecting deterioration of oil tank floor, such as blister and delamination of corrosion protection coating, or corrosion of the bottom steel plate under coating. Experimental studies were conducted to demonstrate the practicability of developed techniques. It was found that the pulse heating infrared thermography was utilized for effective screening inspection and THz-TDS imaging technique performed well for the detailed inspection of coating deterioration and steel corrosion.SPIE-INT SOC OPTICAL ENGINEERING, 2016年, THERMOSENSE: THERMAL INFRARED APPLICATIONS XXXVIII, 9861, 98611B, 英語[査読有り]研究論文(国際会議プロシーディングス)
- Long-standing steel bridges suffer fatigue cracks, which necessitate immediate inspection, structural integrity evaluation or repair in the life cycle of steel bridges. The authors proposed NDT and NDE techniques employing infrared thermography at certain stage in the life cycle of steel bridges. This paper presents remote measurement of stress field around fatigue cracks in steel bridges for their structural integrity assessments. Further this paper shows experimental results confirming the severity reduction of stress distribution around fatigue cracks after the repair or reinforcement of steel bridges. Copyright (C) 2016 The Authors. Published by Elsevier B.V.ELSEVIER SCIENCE BV, 2016年, 21ST EUROPEAN CONFERENCE ON FRACTURE, (ECF21), 2, 2132 - 2139, 英語[査読有り]研究論文(国際会議プロシーディングス)
- In this paper, a new fatigue limit estimation scheme for austenitic stainless steel based on the dissipated energy is proposed. The new scheme utilizes the phase 2f lock-in infrared method which is a technique for improving the accuracy of a dissipated energy measurement, and evaluates the fatigue limit based on the increasing rate of dissipated energy. This scheme is applied to the pre-strained austenitic stainless steel specimen. The fatigue limit of austenitic stainless steel specimen is increased by the plastic forming process. The phase 2f lock-in infrared method can remove the apparent dissipated energy which is caused by thermoelastic temperature change due to harmonic vibration of fatigue testing machine. The estimation scheme based on the increasing rate of dissipated energy against the stress level can evaluate the fatigue limit of the pre-strained specimen with greater accuracy than the conventional scheme. Copyright (C) 2016 The Authors. Published by Elsevier B.V.ELSEVIER SCIENCE BV, 2016年, 21ST EUROPEAN CONFERENCE ON FRACTURE, (ECF21), 2, 2091 - 2096, 英語[査読有り]研究論文(国際会議プロシーディングス)
- The rolling contact fatigue (RCF) tests were performed on a high-strength steel by a newly developed compact rolling contact fatigue test machine, and the formation and propagation of cracks were observed by the synchrotron radiation computed laminography (SRCL). An increase in the sulfur concentration, i.e., increase in inclusion length, resulted in an increase in the variation of flaking life, and materials with horizontal inclusion showed large variation compared to those with vertical inclusion although average flaking lives are almost identical. In the flaking process, cracks, those were perpendicular to the rolling surface and rolling direction, first formed from an inclusion that was adjacent to the rolling surface. Then, the crack propagated in the depth direction. After the vertical crack propagated to a critical depth, a horizontal crack formed, whose face was parallel to the rolling surface. Finally, the horizontal crack propagated to form flaking. Copyright (C) 2016 The Authors. Published by Elsevier B.V.ELSEVIER SCIENCE BV, 2016年, 21ST EUROPEAN CONFERENCE ON FRACTURE, (ECF21), 2, 3117 - 3124, 英語研究論文(国際会議プロシーディングス)
- In rolling contact fatigue (RCF), cracks usually initiate from inclusions beneath the surface and propagate to the contact surface. In the present study, synchrotron radiation computed laminography (SRCL) imaging was performed to observe flaking defects during the RCF of a high-strength steel. Specially fabricated inclusion-rich steel plate specimens were employed in the experiments. For the in situ observation of crack propagation, a compact RCF testing machine was developed, and a 4D analysis scheme was applied to the data obtained by SRCL. RCF tests were carried out near the measurement hatch of the beam line used SRCL to enable the successive observation of crack initiation and growth behaviors. Specimens before and after the occurrence of flaking were observed by SRCL, and flaking defects and cracks under the surface were successfully detected. As a result, details of the crack initiation and flaking process in RCF could be discussed. Shear-type horizontal cracks were found to initiate after the initiation and propagation of tensile-type vertical cracks along inclusions, where the face of the vertical cracks was perpendicular to the rolling direction and rolling surface. Therefore, the formation of vertical cracks is considered to affect shear-type crack formation and flaking, where the shape and length of inclusions also affect the initiation and propagation of vertical cracks.Gruppo Italiano Frattura, 2015年10月, Frattura ed Integrita Strutturale, 9(34) (34), 246 - 254, 英語[査読有り]研究論文(学術雑誌)
- 2015年10月, Proceedings of ICFD2015 International conference on Flow Dynamics, 644 - 645, 英語Fatigue strength Evaluation Based on Dissipated Energy Measurement for Cavitation Peening Material[査読有り][招待有り]研究論文(国際会議プロシーディングス)
- The objective of the present paper is to clarify the effect of defect length in depth direction on rolling contact fatigue (RCF) crack propagation in high strength steel. RCF test and synchrotron radiation micro computed tomography (SR micro CT) imaging were conducted. In the case of the defect with the 15 μm diameter, flaking life decreased with increasing defect length. In a comparison of the CT image and the SEM view, the shapes of defects and the locations of the horizontal cracks were almost the same respectively. The mechanism of RCF crack propagation was discussed by finite element (FE) analysis. Defects led to higher tensile residual stress than that without defects in the region where the defect exists. The shear stress range at 0.1 mm in depth on the middle line of the defect and the range of mode II stress intensity factor at the bottom of a vertical crack increased with increasing defect length.Gruppo Italiano Frattura, 2015年10月, Frattura ed Integrita Strutturale, 9(34) (34), 334 - 340, 英語[査読有り]研究論文(学術雑誌)
- 2015年09月, Proceedings of 13th International Workshop on Advanced Infrared Technology & Applications, 229 - 233, 英語Nondestructive detection of corrosion damage under corrosion protection coating using infrared thermography and terahertz imaging[査読有り][招待有り]研究論文(国際会議プロシーディングス)
- 2015年09月, Proceedings of 13th International Workshop on Advanced Infrared Technology & Applications, 36 - 40, 英語Accuracy improvement of dissipated energy measurement and fatigue limit estimation by using phase information[査読有り][招待有り]研究論文(国際会議プロシーディングス)
- The evaluation of fatigue limit is important in designing products. The fatigue limit estimation based on dissipated energy has been getting considerable attentions. In this method, the temperature change due to irreversible energy dissipation is measured by infrared thermography for various levels of stress amplitude. It is known that the dissipated energy increases with increasing stress levels, and a certain stress level, where the change in dissipated energy shows the sharp increase, coincides with the fatigue limit of the material. In this study, the dissipated energy measurement was applied to the estimation of the crack initiation location. The fatigue limit estimation was carried out for the specimen that had multiple notches. The estimated fatigue limit showed similar value at each notch and that gave close agreement with the fatigue limit obtained from conventional fatigue tests. On the other hand, the magnitude and change of dissipated energy at each notch were different. In experiments of fatigue limit estimation, the notch, where the maximum value of dissipated energy was measured, was different from the notch where the maximum sum of principal stress was measured. To investigate the location of the crack initiation, the same specimen was carried out in the constant stress amplitude fatigue test. It was found that the notch where the largest dissipated energy was observed coincided with the crack initiated notch. Therefore, it was considered that the location of crack initiation could be estimated at the early period of fatigue by using the dissipated energy measurement.Society of Materials Science Japan, 2015年08月, Zairyo/Journal of the Society of Materials Science, Japan, 64(8) (8), 668 - 674, 日本語[査読有り]研究論文(学術雑誌)
- 高輝度光科学研究センター, 2015年08月, 平成26年度 SPring-8 新産業分野支援課題・一般課題(産業分野)実施報告書(2014A), 38 - 41, 日本語放射光X線ラミノグラフィによる転動疲労き裂発生・進展挙動のその場観察-介在物寸法・形状の影響[査読有り][招待有り]研究論文(大学,研究機関等紀要)
- 高輝度光科学研究センター, 2015年08月, 平成26年度 SPring-8 新産業分野支援課題・一般課題(産業分野)実施報告書(2014A), 149 - 152, 日本語回折コントラストトモグラフィを用いた結晶粒内の転位密度評価[査読有り][招待有り]研究論文(大学,研究機関等紀要)
- 日本材料学会 疲労部門委員会, 2015年07月, 第321回疲労部門委員会研究討論会資料, 8 - 12, 日本語高輝度放射光の回折コントラストトモグラフィーによる疲労すべりの3D観察[招待有り]研究論文(研究会,シンポジウム資料等)
- 高輝度光科学研究センター, 2015年07月, Spring-8/SACRA利用研究成果集, 3(2) (2), 457 - 460, 日本語結晶3Dマッピング法を用いた多結晶金属材料の塑性ひずみの測定[査読有り]研究論文(大学,研究機関等紀要)
- 高輝度光科学研究センター, 2015年03月, 平成26年度 SPring-8 産業分野支援課題・一般課題(産業分野)実施報告書(2014A), 日本語放射光ラミノグラフィによる介在物からの転動き裂発生およびはく離形態挙動のその場観察[査読有り][招待有り]研究論文(大学,研究機関等紀要)
- 高輝度光科学研究センター, 2015年03月, 平成26年度 SPring-8 産業分野支援課題・一般課題(産業分野)実施報告書(2014A), 日本語回折コントラストトモグラフィを用いた多結晶金属材料における高サイクル疲労損傷評価[査読有り][招待有り]研究論文(大学,研究機関等紀要)
- 高輝度光科学研究センター, 2015年03月, 平成26年度 SPring-8 産業分野支援課題・一般課題(産業分野)実施報告書(2014A), 日本語ラミノグラフィによる介在物を起点とした転動疲労き裂の進展およびはく離形態挙動のその場観察[査読有り][招待有り]研究論文(大学,研究機関等紀要)
- Fatigue limit estimation based on dissipated energy measurement was applied to the evaluation of shot peening effect on fatigue limit improvement. It was found that estimated fatigue limit based on dissipated energy for the shot peened material showed conservative value, compared with that obtained by conventional fatigue tests. In the constant stress amplitude fatigue test, dissipated energy for unbroken specimens with shot peening treatment was larger than that for broken as-received specimen. SEM observation for unbroken specimens with shot peening treatment showed that some micro cracks existed inside of dents. These facts indicated that dissipated energy caused by structure change leading to crack initiation was observed at stress amplitude above the estimated fatigue limit for unbroken specimens with shot peening treatment, however crack propagation was inhibited by compressive residual stress field around initiated micro cracks. Therefore, it was considered that fatigue limit estimated by dissipated energy measurement indicated crack initiation limit in total fatigue life.Society of Materials Science Japan, 2014年12月, Zairyo/Journal of the Society of Materials Science, Japan, 63(12) (12), 850 - 856, 日本語[査読有り]研究論文(学術雑誌)
- 日本材料学会, 2014年12月, 材料, 63(12) (12), 850 - 856, 日本語[査読有り]研究論文(学術雑誌)
- 2014年12月, Recent Advances in Structural Integrity Analysis: Proceedings of the International Congress (APCF SIF 2014), 47 - 51, 英語A new approach for evaluating stress intensity factor based on thermoelastic stress analysis[査読有り]研究論文(国際会議プロシーディングス)
- The objectives of the present paper are to clarify the rolling contact fatigue (RCF) crack path in high strength steel with artificial defects using synchrotron radiation micro-computed tomography (SR micro CT) imaging and to discuss the mechanism of RCF crack propagation by finite element (FE) analysis. Two crack types, a vertical crack and a horizontal crack, were observed around the artificial defect by SR micro CT. The stress intensity factor (SIF) of horizontal cracks, calculated by FE analysis, increased by the existence of vertical cracks. The interaction between these two crack types dominates RCF crack propagation originating from artificial defects. (C) 2014 Elsevier Ltd. All rights reserved.ELSEVIER SCI LTD, 2014年11月, INTERNATIONAL JOURNAL OF FATIGUE, 68, 168 - 177, 英語[査読有り]研究論文(学術雑誌)
- 高輝度光科学研究センター, 2014年09月, 平成25年度 SPring-8 重点産業化促進課題・一般課題(産業分野)実施報告書(2013B), 日本語放射光ラミノグラフィによる介在物起点の転動疲労き裂の観察[査読有り][招待有り]研究論文(大学,研究機関等紀要)
- 高輝度光科学研究センター, 2014年09月, 平成25年度 SPring-8 重点産業化促進課題・一般課題(産業分野)実施報告書(2013B), 日本語多結晶金属材料における回折コントラストトモグラフィによる金属組織評価の高精度化[査読有り][招待有り]研究論文(大学,研究機関等紀要)
- 2014年07月, Proceedings of 16th International Conference on Experimental Mechanics, 英語Fatigue Limit Estimation Based on Dissipated Energy Measurement for Surface Modified Materials[査読有り]研究論文(国際会議プロシーディングス)
- 2014年07月, Proceedings of 16th International Conference on Experimental Mechanics, 英語Experimental Study of Relationship Between Energy Dissipation and Fatigue Damage Initiation Based on Observation of Slip Band by Atomic Force Microscope[査読有り]研究論文(国際会議プロシーディングス)
- In this work, interfacial fracture toughness between treated fiber and matrix was investigated by using double shear test method. Susrface treatment on the oil palm empty fruit bunch (OPEFB) fibers was performed to improve the interfacial bosnding properties of natural fiber reinforced Poly(L-lactide acid) composites. Three fibers model composite and four fibers model compositeScientific Research, 2014年04月, Open Journal of Composite Material, 4, 97 - 105, 英語[査読有り]研究論文(学術雑誌)
- The three dimensional grain mapping technique for polycrystalline material, which is called X-ray diffraction contrast tomography (DCT) has proposed. In the present study, the measurement of DCT was conducted in SPring-8, which is the brightest synchrotron radiation facility in Japan, and the condition of measurement and data procedure are discussed. Developed technique was appTrans. Tech. Pub., 2014年04月, Materials Science Forum, 783-786, 2359 - 2364, 英語[査読有り]研究論文(学術雑誌)
- The fatigue limit estimation method based on energy dissipation measured by infrared thermography has been introduced in various industries in recent years because of its time and cost effectiveness. In this method, the temperature change due to irreversible energy dissipation during one loading cycle is measured for different levels of applied stress amplitude. The obtained relationship between temperature change and stress amplitude shows a significant inflection at a certain stress level where temperature change due to energy dissipation shows a steep increase. It is known that this stress level coincides with the fatigue limit. In this study, the measurement conditions for appropriate fatigue limit determination based on the energy dissipation are discussed experimentally in conjunction with: (i) the required number of loading cycles in each stress level, (ii) the appropriate number of loading cycles, (iii) the influence of loading history and fatigue damage accumulation, and (iv) the influence of loading frequency.非破壊検査協会, 2014年03月, 非破壊検査, 63(3) (3), 153 - 160, 日本語[査読有り]研究論文(学術雑誌)
- Oil palm fiber (OPF) extracted from empty fruit bunches is proven as a good raw material for bio-composites. The statistical variability in single fiber strength was observed due to the randomly distributed flaws along the fiber. In this study, the effect of gauge length on tensile strength of OPFs has been investigated. The Weibull weakest link distribution model was applied t2014年03月, Open Journal of Composite Materials, 2014, Vol. 4, pp. 72-77., 4, 72 - 77, 英語[査読有り]研究論文(学術雑誌)
- 2014年, 平成26 年度SPring-8 成果公開優先利用課題実験報告書, 2014A1020Ti-6Al-4V 合金における内部起点型微小疲労き裂の発生および進展初期過程のμCT イメージングによる観察研究論文(学術雑誌)
- 2014年, 平成26 年度SPring-8 一般課題実験報告書, 2014A1459Ti-6Al-4V 合金における材料内部組織の放射光μCT イメージングによる非破壊観察研究論文(学術雑誌)
- In the present study, micro computed tomography (mu CT) imaging by using ultra-bright synchrotron radiation X-ray (SR mu CT), which is generated at a facility located in Japan and called SPring-8 (Super Photon ring-8 GeV), is used to observe torsion fatigue crack propagation behavior in round bars. It is well known that the transition of crack propagation from the shear mode to the tensile mode takes place in the above case. The transition condition, however, was not discussed in detail in the past, since the crack growth behavior under the surface cannot be provided precisely by the conventional techniques, such as optical microscope, scanning electron microscope, and atomic force microscope. A compact torsion fatigue-testing machine has been recently developed to conduct fatigue tests and measurements of SR mu CT concurrently at Spring-8. Therefore, the shape of torsion fatigue cracks can be evaluated quantitatively and nondestructively, and the transition of crack propagation from the shear mode to the tensile mode can be observed three-dimensionally. The condition of the transition of crack propagation is discussed by considering the three-dimensional shape of cracks. (C) 2013 Elsevier Ltd. All rights reserved.ELSEVIER SCI LTD, 2014年01月, INTERNATIONAL JOURNAL OF FATIGUE, 58, 158 - 165, 英語[査読有り][招待有り]研究論文(学術雑誌)
- Combined methods to obtain ultra-fine grain (UFG) α-brass samples are proposed. Severe plastic deformation followed by recrystallization was conducted, where multiple rolling and equal channel angular pressing (ECAP) were employed. Recrystallization was accomplished by heat-treatment after the severe plastic deformation, and the grain size after the severe plastic deformation wTRANS TECH PUBLICATIONS LTD, 2014年, Advanced Materials Research, Vols. 891-892, pp.1125-1130, 2014, 891-892, 1125 - 1130, 英語[査読有り]研究論文(国際会議プロシーディングス)
- In recent years, fatigue limit estimation based on dissipated energy has been introduced in various industries because of its time and cost effectiveness. However, the mechanism of energy dissipation and the relationship between energy dissipation and fatigue damage have not been investigated well. In this study, mechanism of energy dissipation is investigated in relation with formulation of slip bands for JIS type 316L stainless steel through observation of slip bands by optical microscope and atomic force microscope.TRANS TECH PUBLICATIONS LTD, 2014年, 11TH INTERNATIONAL FATIGUE CONGRESS, PTS 1 AND 2, 891-892, 606 - +, 英語[査読有り]研究論文(国際会議プロシーディングス)
- The three dimensional grain mapping technique for polycrystalline material, which is called X-ray diffraction contrast tomography (DCT) has proposed. In the present study, the measurement of DCT was conducted in SPring-8, which is the brightest synchrotron radiation facility in Japan, and the condition of measurement and data procedure are discussed. Developed technique was applied to aluminium alloy and stainless steel. The shape and location of grain could be determined by the developed three-dimensional mapping technique using the apparatus in a bending beam line of SPring-8. To evaluate plastic deformation, the grain orientation spreads of individual grains were measured. The grain orientation spread is caused by the mosaicity, which relates to the dislocation structure in a grain. The grain orientation spread was found to increase with increasing plastic strain. Fatigue damage also could be evaluated by the grain orientation spread in the DCT measurement.TRANS TECH PUBLICATIONS LTD, 2014年, 11TH INTERNATIONAL FATIGUE CONGRESS, PTS 1 AND 2, 891-892, 600 - 605, 英語[査読有り]研究論文(国際会議プロシーディングス)
- Micro computed laminography imaging using ultra -bright synchrotron radiation (SRCL) was applied to the observation of flaking defects under rolling contact fatigue (RCF) of a high strength steel. Specially fabricated inclusion rich steel plate specimens were employed for the experiments. RCF fatigue tests were carried out near the measurement hatch of SRCL for successive observation of crack initiation and growth behaviors. Specimens before and after the initiation of flaking were observed by SRCL, and the flaking defects and cracks under the surface were successfully detected. The shape and location of RCF crack obtained by SRCL imaging were almost coincident with those obtained by SEM, and detail process of crack initiation and flaking in RCF process can be discussed. (C) 2014 Elsevier Ltd.ELSEVIER SCIENCE BV, 2014年, 20TH EUROPEAN CONFERENCE ON FRACTURE, 3, 159 - 164, 英語[査読有り]研究論文(国際会議プロシーディングス)
- It is difficult to evaluate the corrosion pit using normal observation methods because of the complex shape of the pit and its passive film. In this study, measurements of pit and crack formation in corrosion fatigue tests of highstrength aluminum alloy, 7075-T651 were conducted by synchrotron radiation CT imaging. 3D/4D analysis was applied to the observation of corrosion pit growth and crack initiation in corrosion fatigue tests. Pits and inclusions were recognized individually in 3D/4D analysis. The corrosion pits showed complex shapes, and parts of pits grew under the surface of specimens along inclusions. It was found that the behavior of the corrosion pit under the surface was affected by the inclusions distribution. The stress intensity factor range ΔK was calculated based on the measured shape and dimensions of the corrosion pit. The value of ΔK increased with increasing loading cycles, and the value of Δ K at the location of crack initiation indicated larger than 0.9 MPa m1/2, which was similar to the threshold stress intensity factor range ΔKth for corrosion fatigue of A7075-T651.軽金属学会, 2014年, 軽金属, 64(11) (11), 564 - 569, 日本語[査読有り]研究論文(学術雑誌)
- In recent years, fatigue limit estimation based on dissipated energy is being introduced in various industries because of its time and cost effectiveness. However, the energy dissipation mechanism and the relationship between energy dissipation and fatigue damage have not been well investigated. In the 1st report, the present authors conducted fatigue limit estimation based on dissipated energy measurement and conventional fatigue test for JIS type 304 and 316L austenitic stainless steel. We found that the fatigue limit of the type 316L steel could be precisely estimated, although estimated fatigue limit of the type 304 steel was conservative values compared with that obtained by conventional fatigue tests. It was considered that the fatigue limit estimation method based on dissipated energy could not evaluate the microstructure change, such as dislocation and phase transformation during short cyclic loading. In this study, fatigue tests under the constant stress amplitude were conducted for austenitic stainless steel to investigate the relationship between dissipated energy and microstructure change during fatigue tests. It was found for the type 316L steel that tendency of the observed dissipated energy during the fatigue tests was similar as that of plastic strain energy. On the other hand, for the type 304 steel, the dissipated energy decreased in spite of increasing plastic strain energy around N = 105cycles, when the applied stress amplitude was close to the actual fatigue limit. It is considered from the observation of the change in martensitic volume fraction, the decrease of dissipated energy was caused by the martensitic transformation some amount of irreversible plastic strain energy was consumed for phase transformation. It was found from the experimental studies that dissipated energy reflects the microstructure changes, such as material softening, hardening and martensitic phase transformation. Therefore, the condition of the number of cycles in the fatigue limit estimation based on the dissipated energy should be changed depending on the behavior of microstructure change in material under cyclic loading. © 2013 The Society of Materials Science, Japan.日本材料学会, 2013年09月, 材料, 62(9) (9), 554 - 561, 日本語[査読有り]研究論文(学術雑誌)
- 2013年06月, 平成25年度 SPring-8 重点産業利用課題・一般課題(産業分野)実施報告書(2013A), 2013A, 1645, 日本語回折コントラストトモグラフィによる多結晶金属材料の疲労損傷評価[査読有り][招待有り]研究論文(大学,研究機関等紀要)
- 2013年02月, 平成24年度 SPring-8 重点産業利用課題・一般課題(産業分野)実績報告書(2012A), 56 - 59, 日本語結晶粒3Dマッピング法を用いた塑性ひずみの評価[査読有り]研究論文(その他学術会議資料等)
- In recent years, fatigue limit estimation based on dissipated energy is getting an increasing attention in various industries because of its time and cost effectiveness. Heat treatment is applied to the material and machine components for the improvement of the mechanical properties. In this study, fatigue limit estimation based on dissipated energy measurement was applied to t日本機械学会, 2013年, 日本機械学会論文集A編, 79(807) (807), 1581 - 1592, 日本語[査読有り]研究論文(学術雑誌)
- In recent years, fatigue limit estimation based on energy dissipation has been getting considerable attentions. In this method, temperature change due to irreversible energy dissipation is measured by infrared thermography for various levels of stress amplitude. It is known that the dissipated energy increases with increasing stress levels, and a certain stress level where the change in dissipated energy shows sharp increase coincides with fatigue limit. However, cause and effect relationship between energy dissipating mechanism and fatigue damage has not been investigated well. In this study, effect of phase transformation on fatigue limit estimation based on dissipated energy is investigated for austenitic stainless steel. Fatigue limit estimation based on dissipated energy and conventional fatigue test were conducted for JIS type 304 and type 316L austenitic stainless steel. It was found from experimental studies that fatigue limit of 316L stainless steel obtained from dissipated energy coincided with that by conventional fatigue test on the other hand fatigue limit of type 304 stainless steel estimated by dissipated energy measurement gave conservative value compared with that by conventional fatigue test. In the case of type 304 stainless steel, plastic deformation led to a phase transformation from austenite into martensite. As the result, amount of emitted dissipated energy decreased since some amount of irreversible plastic strain energy was consumed for phase transformation, and this affected on the fatigue limit estimation based on energy dissipation. © 2012 The Society of Materials Science, Japan.2012年12月, Zairyo/Journal of the Society of Materials Science, Japan, 61(12) (12), 953 - 959, 日本語[査読有り]研究論文(学術雑誌)
- 2012年12月, 材料, 61(12) (12), 953 - 959, 日本語オーステナイト系ステンレス鋼の疲労限度評価[査読有り]研究論文(学術雑誌)
- 2012年09月, Proceedings of the 4th International Conference on Crack Paths (CD-ROM), 035, 英語Observation of Fatigue Crack Propagation Mode Transition under Cyclic Torsion Using Micro-CT Imaging with Ultra-Bright Synchrotron Radiation[査読有り]研究論文(国際会議プロシーディングス)
- RELATIONSHIP BETWEEN DISSIPATED ENERGY AND FATIGUE LIMIT FOR AUSTENITIC STAINLESS STEELRecently, rapid prototype modeling is required in industry due to accelerated production cycles. Therefore, effective fatigue life design method is required taking the place of conventional laboratory fatigue test based on 10 million stress cycles. Therefore, fatigue limit estimation based on energy dissipation measured by infrared thermography has been getting an increasing attention, because of its time and cost effectiveness. This technique has been welcomed mainly in automotive industries for evaluating fatigue limit of steel for automobile bodies. However the fundamental principle of this method has not been clarified yet. In this study, fatigue test is conducted for austenitic stainless steel. Temperature change due to dissipated energy, martensite fraction and strain are continuously measured to discuss energy dissipation mechanism related to plastic strain and transformation of microstructure during fatigue test.INEGI-INST ENGENHARIA MECANICA E GESTAO INDUSTRIAL, 2012年, ICEM15: 15TH INTERNATIONAL CONFERENCE ON EXPERIMENTAL MECHANICS, PAPER REF 2600, pp.1 - 9, 英語[査読有り]研究論文(国際会議プロシーディングス)
- OBSERVATION OF CRACKS IN CARBON STEEL UNDER CONTACT ROLLING FATIGUE BY MICRO CT IMAGING USING ULTRA-BRIGHT SYNCHROTRON RADIATIONMicro computed tomography imaging using ultra-bright synchrotron radiation (SR mu CT) was applied to the observation of flaking defects under rolling contact fatigue (RCF) of a carbon steels. The specimens with artificial defects, which simulated inclusions, were employed for the fatigue tests. Samples before and after the initiations of flaking were observed by the SR mu CT, and the flaking defects and cracks were successfully detected. The shape and location of RCF crack obtained by SR mu CT imaging were almost consistent with those obtained by SEM. It was found that the detail process of crack initiation and flaking in the rolling contact fatigue process could be discussed from the results obtained by SR mu CT.INEGI-INST ENGENHARIA MECANICA E GESTAO INDUSTRIAL, 2012年, ICEM15: 15TH INTERNATIONAL CONFERENCE ON EXPERIMENTAL MECHANICS, 2635, 英語[査読有り]研究論文(国際会議プロシーディングス)
- DEVELOPMENT OF THREE-DIMENSIONAL GRAIN MAPPING TECHNIQUE IN SPRING-8 AND EVALUATION OF PLASTIC STRAINThe three dimensional grain mapping technique for polycrystalline material, that is termed Xray diffraction contrast tomography (DCT) has proposed. In the present study, the measurement of DCT were conducted in SPring-8 and the condition of measurement and data procedure were discussed. Developed technique was applied to aluminium alloy and stainless steel. It was found that the shape and location of grain can be determined by three-dimensional mapping technique using the apparatus in SPring-8, BL19B2 bending beam line. Next, for evaluation of plastic deformation, the internal grain orientation spread of the individual grain was counted. The grain orientation spread is caused by the mosaicity, which related to the change of microstructure. The grain orientation spread increased with increased in the tension stress in the plastic deformation region. It is possible to evaluate fatigue damage in microstructure, such as crack initiation, by the DCT technique and using the grain orientation spread as one of the fatigue damage parameters.INEGI-INST ENGENHARIA MECANICA E GESTAO INDUSTRIAL, 2012年, ICEM15: 15TH INTERNATIONAL CONFERENCE ON EXPERIMENTAL MECHANICS, CD-ROM(2772) (2772), 英語[査読有り]研究論文(国際会議プロシーディングス)
- DEVELOPMENT OF THREE-DIMENSIONAL GRAIN MAPPING TECHNIQUE IN SPRING-8 AND EVALUATION OF PLASTIC STRAINThe three dimensional grain mapping technique for polycrystalline material, that is termed Xray diffraction contrast tomography (DCT) has proposed. In the present study, the measurement of DCT were conducted in SPring-8 and the condition of measurement and data procedure were discussed. Developed technique was applied to aluminium alloy and stainless steel. It was found that the shape and location of grain can be determined by three-dimensional mapping technique using the apparatus in SPring-8, BL19B2 bending beam line. Next, for evaluation of plastic deformation, the internal grain orientation spread of the individual grain was counted. The grain orientation spread is caused by the mosaicity, which related to the change of microstructure. The grain orientation spread increased with increased in the tension stress in the plastic deformation region. It is possible to evaluate fatigue damage in microstructure, such as crack initiation, by the DCT technique and using the grain orientation spread as one of the fatigue damage parameters.INEGI-INST ENGENHARIA MECANICA E GESTAO INDUSTRIAL, 2012年, ICEM15: 15TH INTERNATIONAL CONFERENCE ON EXPERIMENTAL MECHANICS, 2772, 英語[査読有り]研究論文(国際会議プロシーディングス)
- 日本材料学会, 2011年09月, Proc. of ATEM’11 International Conference on Advanced Technology in Experimental Mechanics 2011, CD-ROM, 121 - 122, 英語Dissipated energy evaluation during fatigue test for austenitic stainless steel with thermography研究論文(国際会議プロシーディングス)
- In the present study, synchrotron radiation micro computed tomography (SR mu CT) imaging of SPring-8 was applied to the observation of the torsion fatigue crack propagation behavior. The transition of crack propagation from Mode II to I occurs under torsion fatigue. The conventional technique, such as optical microscope and scanning microscope, cannot give us the crack growth behavior under the surface. Therefore, the transition of crack propagation could not be discussed in detail. The compact torsion fatigue-testing machine was developed for fatigue testing at SPring-8, and the torsion fatigue tests and measurements of SR micro-CT were carried out alternately. The shape of torsion fatigue cracks could be evaluated quantitatively and nondestructively. Transition of crack propagation from Mode II to Mode I under the surface could be observed. The condition of transition of crack propagation was discussed by using three-dimensional shape of cracks. (C) 2011 Published by Elsevier Ltd. Selection and peer-review under responsibility of ICM11ELSEVIER SCIENCE BV, 2011年, 11TH INTERNATIONAL CONFERENCE ON THE MECHANICAL BEHAVIOR OF MATERIALS (ICM11), 10, 1479 - 1484, 英語[査読有り]研究論文(国際会議プロシーディングス)
- Measurement of shape and dimension of pits and cracks formed in corrosion fatigue tests of a high-strength aluminium alloy, 7075-T651 were conducted by computed-tomography using ultra bright synchrotron radiation X-ray. Complex corrosion process could be observed and detail shapes of corrosion pits could be identified. Sometimes, corrosion pit and corroded area were formed under passive film, and those were not observed from the surface.TRANS TECH PUBLICATIONS LTD, 2011年, EXPERIMENTAL MECHANICS AND MATERIALS, 83, 162 - 167, 英語[査読有り]研究論文(国際会議プロシーディングス)
- The Society of Materials Science, Japan, 2010年, 材料, 59(10) (10), 814 - 814
- Micro computer-tomography (mu CT) using ultrabright synchrotron radiation was applied to observe the shape of fretting fatigue cracks in a titanium alloy. Three dimensional shape and coalescence of fretting fatigue cracks could be observed, and the shapes of the cracks obtained by the imaging agreed well with that obtained by the stereogram analysis of fracture surface using scanning electron microscopy. Transition of crack propagation mode inside specimen in fretting fatigue also could be observed nondestructively.SPIE-INT SOC OPTICAL ENGINEERING, 2010年, FOURTH INTERNATIONAL CONFERENCE ON EXPERIMENTAL MECHANICS, 7522, 英語[査読有り]研究論文(国際会議プロシーディングス)
- In the present study, synchrotron radiation micro computed tomography (SR mu CT) imaging of SPring-8 was applied to the observation of the torsion fatigue crack propagation behavior. The transition of crack propagation from Mode II to I occurs under torsion fatigue. The conventional technique, such as optical microscope and scanning microscope, cannot give us the crack growth behavior under the surface. Therefore, the transition of crack propagation could not be discussed in detail. The compact torsion fatigue-testing machine was developed for fatigue testing at SPring-8, and the torsion fatigue tests and measurements of SR micro-CT were carried out alternately. The shape of torsion fatigue cracks could be evaluated quantitatively and nondestructively. Transition of crack propagation from Mode II to Mode I under the surface could be observed. The condition of transition of crack propagation was discussed by using three-dimensional shape of cracks. (C) 2010 Published by Elsevier Ltd.ELSEVIER SCIENCE BV, 2010年, Procedia Engineering, 2(1) (1), 1413 - 1419, 英語[査読有り]研究論文(国際会議プロシーディングス)
- Measurements of the shape and dimensions of the pits and cracks formed in corrosion fatigue tests of a high-strength aluminium alloy, 7075-T651 were conducted by computed-tomography using ultra bright synchrotron radiation X-ray. Complex corrosion process could be observed and detail shape of corrosion pits could be identified. Sometimes, corrosion pit was formed under passive film, and those were not observed from the surface.E D P SCIENCES, 2010年, ICEM 14: 14TH INTERNATIONAL CONFERENCE ON EXPERIMENTAL MECHANICS, VOL 6, 6, 英語[査読有り]研究論文(国際会議プロシーディングス)
- SQUID (Superconducting Quantum Interface Device) has high magnetic sensitivity and high magnetic resolution. In this study, high-temperature SQUID microscope was applied to the detection of defects in printed wire. SQUID microscope with high permeability needle (flux guide) showed high spatial resolution measurement of the sample in air at room temperature. The distribution of magnetic field around printed wires that subjected to DC current was measured. The results of measuring magnetic field for 0.7mm line and spacing meander lines showed the effect of flux guide on spatial resolution improvement. The distribution of magnetic field around the printed wire with defects has been analyzed numerically. It was found that the magnetic field distribution and magnetic field gradient showed that changes according to the parameters of defect such as defect width and location. SQUID microscope was applied to inspect the imperfections in the width and thickness of the printed wire. It was found from these measurements that the SQUID microscope could measure the changes in magnetic field distribution induced by the imperfection in the width and thickness. The shape of measured magnetic field distribution for printed wire having the defect in width was similar to that of calculated distribution. Defect in small sized wires with the width of 200μm also could be detected by the measured magnetic field gradient distribution. © 2009 The Society of Materials Science.2009年10月, 材料, 58(10) (10), 808 - 814, 日本語[査読有り]研究論文(学術雑誌)
- 2009年05月, Proceedings of the 12th International Conference on Fracture (ICF-12), CD-ROM, 英語Observation of Fretting Fatigue Cracks by Micro Computed Tomography with Synchrotron Radiation[査読有り]研究論文(学術雑誌)
- In the present study, the ultra-bright synchrotron radiation X-ray was applied to the observation of small cracks in steels. It is important to investigate the applicability of synchrotron radiation X-ray and several parameters for the observation of defects in steels, which is widely used in industrial structures. The Synchrotron radiation X-ray micro computed tomography (SR-μCT) was applied to the three-dimensional observation of small cracks which were initiated either in fretting or in torsion fatigue test. It was found that phase contrast imaging technique has enabled the reconstruction of clear crack images with small opening displacement of about 1μm or submicron scale. The shapes of surface and inside cracks obtained by SR-μCT were agreed well with those by the scanning electronic microscopy. SR-μCT can also display characteristic inside shape of fretting fatigue cracks those were not perpendicular to the body axis and coalesced each other under surface. Torsion fatigue cracks of 10-15μm in depth can be also observed in high-strength steel using SR-μCT. © 2007 The Society of Materials Science.2007年10月, 材料, 56(10) (10), 951 - 957, 日本語[査読有り]研究論文(学術雑誌)
- 2007年09月, Proceedings of ATEM'07, CD-ROM, 英語Fatigue Damage Evaluation of SUS304 Steel Using Magnetism Change in Fatigue Process[査読有り]研究論文(学術雑誌)
- 2007年08月, Fourth International Conference on Very High Cycle Fatigue, Edited by John E. Allison, J. Wayne Jones, James M. Larsen, and Robert O. Ritchie, TMS, Warendale, Pennsylvania, pp.67-72, 英語Observation of Inclusions and Defects in Steels by Micro Computed-tomography using Ultrabright Synchrotron Radiation[査読有り]研究論文(国際会議プロシーディングス)
- SQUID (Super conducting Quantum interference device) has high magnetic sensitivity and high magnetic resolution. Minute magnetic fields up to 10^-8 gauss can be detected by SQUID. Therefore, Nondestructive Testing (NDT) using SQUID can detect the change in magnetic field distribution due to the small defect that cannot be detected by conventional NDT method. The measurement system using SQUID was developed and applied to detect the current path by the measured magnetic field distribution when DC current was applied. It was found that the location of current path and size of line spacing could be identified by measured magnetic field. The measurement system using SQUID could measure the change in the magnetic filed distribution due to the notch in current path. It was considered from these results that the small defect in current path could be detected and evaluated from the magnetic field distribution measured by SQUID.一般社団法人日本機械学会, 2007年, 年次大会講演論文集, 2007, 283 - 284, 日本語
- For the detection of fatigue damage before crack initiation in an austenitic stainless steel,SUS304, we investigated the possibility of the fatigue damage detection and evaluation from the change in the magnetization. Fatigue tests and measurements of magnetization conducted under the stress ration, R, of -1. The experimental results showed that the location, where the maximum changes in the value of the changes in the leakage magnetic flux density B_z observed, coincided with the location of the stress concentration, where the crack was formed, and the value of B_z rapidly increased before crack initiation. When no crack was found, increasing rate of B_z decreased with increasing the number of cycles, and the value of B_z was saturated to a certain value. It was found that fatigue damage before crack initiation can be detected from the change in the magnetization in SUS304 steel.一般社団法人日本機械学会, 2007年, 年次大会講演論文集, 2007, 295 - 296, 日本語
- When a piezoelectric film is glued on the surface of a structure member subjected to mechanical load, a distribution of electric potential is induced. In the existence of defects in the member, a characteristic variation of electric potential is observed. Based on this phenomenon, the passive electric potential CT (computed tomography) method is developed for detecting and identifying defects in a structure. In this study, the applicability of the passive electric potential CT method to the identification of a delamination in a CFRP laminate was experimentally examined. CFRP laminate specimens, which have an artificial interlaminer delamination, with a piezoelectric film on their surface were subjected to three-point bending. The electric potential distribution on the piezoelectric film was measured by a non-contact voltmeter. Characteristic variation reflecting the location and the size of the delamination is observed in the measured electric potential distributions. To identify the delamination, an inverse method was constructed based on the least-squares residual evaluated between the measured and computed electric potential distributions. The location and size of the delamination were estimated accurately. It was shown that the passive electric potential CT method using a piezoelectric film was useful for the quantitative identification of interlaminar delamination in laminated composite materials. © 2007 IOP Publishing Ltd.Institute of Physics Publishing, 2007年01月, Measurement Science and Technology, 18(1) (1), 49 - 56, 英語[査読有り]研究論文(国際会議プロシーディングス)
- The observation of internal microstructures in materials is important to elucidate the mechanisms of ultra-long life fatigue of high-strength steels, and to ensure the integrity of structures. By conventional techniques, such as laboratory X-ray and ultrasonic imaging, the size and shape of subsurface non-metallic inclusions and cracks, those are smaller than 100μm, cannot be measured. Then, in the present study, the ultra-bright synchrotron radiation X-ray was applied to the imaging of subsurface inclusion. To obtain basic data for the measurement, the penetration depth of synchrotron radiation wave in a free-cutting steel was examined. It was found that the depths where the transmitted wave cannot be observed are 100μm for 15 keV, 200μm for 20 keV, 600μm for 25 keV, and 800μm for 30 keV. For the measurement of size and shape of inclusion, synchrotron radiation computed tomography method (SR-CT) was employed. Metallographic structures can be observed in a free-cutting steel, and the diameter of these structures is about 7-10μm. They are considered to be inclusions, which mainly contain manganese sulfide (MnS) or pearlitic phase. To investigate the possibility of detection of pearlitic phase, SR-CT was applied to observe the metallographic structures in carbon steel (S35C), which contains a lot of pearlitic phase and a little inclusion. In this case, no metallographic structure was observed inside specimen. These results indicate that the microstructures those were observed by SR-CT method was inclusions, not pearlitic phase.一般社団法人日本機械学会, 2006年12月, 日本機械学会論文集, 72巻724号1846-1852(724) (724), 1846 - 1852, 日本語[査読有り]研究論文(学術雑誌)
- 2006年09月, New Methods of Damage and Failure Analysis of Structural Parts, pp.277-286, 英語Quantitative Analysis of Inclusions and Fatigue Cracks in Steel by X-ray Computed Tomography Using Ultra-bright Synchrotron Radiation[査読有り]研究論文(学術雑誌)
- In this paper, we examine the applicability of the passive electric potential CT (computed tomography) method to the quantitative identification of three-dimensional cracks in structures. In this method, a piezoelectric film is glued on the surface of structures. The electric potential values on the piezoelectric film change due to the strain distribution on the surface of the structures, when the structures are subjected to an external load. The strain distribution induces an electric potential distribution on the piezoelectric film. Then, this method does not require electric current application, and passively observed electric potential values on piezoelectric film can be used for crack identification. The electric potential distribution on piezoelectric film was investigated numerically and experimentally. It was found that the electric potential distribution shows a characteristic change corresponding to the shape of the surface crack. An inverse method based on the least residual method was applied to crack identification from the electric potential distribution. In this inverse method, the square sum of residuals is evaluated between the measured electric potential distributions and those computed from the electric potential distribution of the piezoelectric film. Three-dimensional surface cracks were identified from the measured electric potential distribution. It was found that the location and size of the crack can be quantitatively estimated using a two-dimensional distribution of electric potential.JAPAN SOC MECHANICAL ENGINEERS, 2006年07月, JSME INTERNATIONAL JOURNAL SERIES A-SOLID MECHANICS AND MATERIAL ENGINEERING, 49(3) (3), 426 - 435, 英語[査読有り]研究論文(学術雑誌)
- Passive electric potential CT method using piezoelectric material for identification of plural cracksThe passive electric potential CT (computed tomography) method using piezoelectric film was applied to the identification Of Plural through cracks. The use of piezoelectric material made it possible to obtain electric potential field without applying electric current. For identification of cracks ail inverse analysis scheme based on the least residual method was applied, in which square sum of residuals is evaluated between the measured electric potential distributions and those computed by using the finite element method. The Akaike information criterion (AIC) was used to estimate the number of cracks. Numerical simulations were carried out oil the identification of plural cracks and a single crack. The location and size of these cracks were quantitatively estimated by the present method. The number of cracks was correctly estimated, even when the plural cracks were closely located and the measured electric potential distribution was similar to that for a single crack.TECH SCIENCE PRESS, 2006年01月, CMES-COMPUTER MODELING IN ENGINEERING & SCIENCES, 11(1) (1), 27 - 36, 英語[査読有り]研究論文(学術雑誌)
- 2005年07月, 日本機械学会論文集A編, 第71巻707号pp. 1038-1045, 日本語受動型電気ポテンシャルCT法を用いた三次元表面き裂の同定に関する実験的検討[査読有り]研究論文(学術雑誌)
- Active and passive electric potential ct methods incorporating inverse analysis schemes for crack and defect identificationThe active and passive electric potential CT (Computed Tomography) methods incorporating inverse analysis schemes for crack identification using the inverse analyses are described. The active method uses the electric potential distribution observed on the surface of the body under electric current application to identify the cracks and defects. The inverse analysis methods were constructed based on comparison between the measured electric potential and that calculated using the boundary element method. The passive electric potential CT method, which does not require the application of the electric current, can be constructed by gluing piezoelectric film on the surface of a cracked structure subjected to mechanical load. The electric potential incurred by mechanical load was used to identify cracks and defects. The electric filed was calculated by applying the finite element method, which takes into account the coupled effect of the strain field and the electric field. The applicability of the passive electric potential CT method was examined numerically and experimentally for a two-dimensional through-crack model. It was found that a characteristic electric potential distribution appeared on the piezoelectric film. The crack can be identified from the electric potential distribution.2005年, 11th International Conference on Fracture 2005, ICF11, 5, 3727 - 3732, 英語研究論文(国際会議プロシーディングス)
- 一般社団法人日本機械学会, 2005年, 材料力学部門講演会講演論文集, 2005, 479 - 480, 日本語
- An experimental study on applicability of passive electric potential CT method to crack identificationThis paper describes the applicability of passive electric potential CT (computed tomography) method which does not require electric current application for damage detection. In this method, piezoelectric film is glued on the surface of structures as a sensor. Electric potential values on the piezoelectric film change due to the strain distribution on the structure, when the structure is subjected to external load. The strain distribution of the cracked body induces a characteristic electric potential distribution on the piezoelectric film. Therefore passively observed electric potential values on piezoelectric film can be used for the defect identification. An inverse method based on the least residual method was applied to the crack identification from the electric potential distribution. In this inverse method, square sum of residuals is evaluated between the measured electric potential distributions and those computed by using the finite element method. This method may be applied to develop an intelligent structure with a function of self-monitoring of flaws and defects. The electric potential on piezoelectric film was measured by the contact type and the non-contact type methods. The measured electric potential distribution was used to identify a crack by using the present inverse method. It was found that the location, size and depth of the crack can be quantitatively identified by the passive electric potential CT method.JAPAN SOC MECHANICAL ENGINEERS, 2004年07月, JSME INTERNATIONAL JOURNAL SERIES A-SOLID MECHANICS AND MATERIAL ENGINEERING, 47(3) (3), 419 - 425, 英語[査読有り]研究論文(学術雑誌)
- When the piezoelectric film is glued on the surface of a cracked material subjected to mechanical load, change in electric potential distribution is observed on the surface of the film. Based on this phenomenon, the passive electric potential CT ( computed tomography) method can be developed, which does not require electric current application for identifying cracks. This method may be applied to develop an intelligent structure with a function of self-monitoring of flaws and defects. For the crack identification from electric potential distribution, an inverse method based on the least residual method was applied, in which square sum of residuals are evaluated between the measured electric potential distributions and those computed by using the finite element method. Numerical simulations were carried out on identification of a through-thickness transverse crack. It was found that the location and size of the crack can be quantitatively identified by the proposed passive electric potential CT method.TAYLOR & FRANCIS LTD, 2004年02月, INVERSE PROBLEMS IN SCIENCE AND ENGINEERING, 12(1) (1), 71 - 79, 英語[査読有り]研究論文(学術雑誌)
- 一般社団法人日本機械学会, 2004年, 材料力学部門講演会講演論文集, 2004, 291 - 292, 日本語
- 一般社団法人日本機械学会, 2004年, 材料力学部門講演会講演論文集, 2004, 299 - 300, 日本語
- 一般社団法人日本機械学会, 2003年, 材料力学部門講演会講演論文集, 2003, 1041 - 1042, 日本語
- When a piezoelectric film is glued on the surface of a cracked structure subjected to mechanical load, change in distribution of electric potential is observed on the surface of piezoelectric film. Based on this phenomenon, the passive electric potential CT (computed tomography) method was developed for the identification of two- and three-dimensional cracks based on the FEM inverse analysis. In this paper, this method was applied to identify through-thickness inclined crack. Electric potential distribution calculated by the FEM showed characteristic changes corresponding to angle and size of crack. Numerical simulations were carried out on estimation of location, size, and angle of the inclined crack. It was found that the passive electric potential CT method using piezoelectric film was useful for the quantitative identification of the through-thickness inclined crack.一般社団法人日本機械学会, 2003年, 年次大会講演論文集, 2003, 103 - 104, 日本語
- This chapter describes the feasibility of passive electric potential Computed Tomography (CT) method which does not require electric current application for detection of damage in laminated composites. In this method, piezoelectric film is glued on the surface of composites as a sensor. Electric potential values on the piezoelectric film change because of the strain distribution on the composite, when the composite is subjected to external load. The strain distribution of the cracked body shows a characteristic electric potential distribution. Therefore, passively observed electric potential values on piezoelectric film can be used for defecting identification. This method may be applied to develop an intelligent structure with a function of self-monitoring of flaws and defects. An inverse method based on the least residual method is applied to the defect identification from the electric potential distribution. In this inverse method, square sum of the residuals are evaluated between the measured electric potential distributions and those computed by using the finite element method. Numerical simulations are carried out on the estimation of the location and size of delamination defect in composites. It is found that the location, size, and depth of the defect can be quantitatively identified by the passive electric potential CT method. © 2003 Elsevier B.V. All rights reserved.Elsevier Ltd., 2003年, Inverse Problems in Engineering Mechanics IV, 195-203, 195 - 203, 英語[査読有り]論文集(書籍)内論文
- When the piezoelectric film is glued on the surface of a cracked material subjected to mechanical load, change in distribution of electric potential is observed on the surface of piezoelectric film. Based on this phenomenon, the passive electric potential CT (computed tomography) method was proposed for identifying two- and three-dimensional cracks. This method uses passively observed electric potential distribution on piezoelectric film induced by the strain distribution of the objective body without applying electric current. Therefore, this method can be applied to develop an intelligent structure with a function of self-monitoring of flaws and defects. In this paper, the passive electric potential CT method using a piezoelectric material is applied to the identification of a through-thickness transverse crack. The effects of crack size and location on electric potential distribution were examined by using the finite element method. For the identification of cracks from electric potential distribution, an inverse method based on the least residual method is applied, in which square sum of residuals are evaluated between the measured electric potential data and those computed by using the finite element method. The crack was identified from experimentally observed electric potential distribution. It was found that the location and size of the crack can be quantitatively identified by the passive electric potential CT method.社団法人日本材料学会, 2002年08月, 材料, 51(8) (8), 926 - 931, 日本語
- 一般社団法人日本機械学会, 2002年, 材料力学部門講演会講演論文集, 2002, 357 - 358, 日本語
- When a piezoelectric film is glued on the surface of a cracked structure subjected to load, change in distribution of electric potential is observed on the surface of piezoelectric film. Based on this phenomenon, the passive electric potential CT (computed tomography) method was developed for identifying two- and three-dimensional cracks. In this study, this method was applied to identify experimentally a three-dimensional crack opening on the back surface. Electric potential distribution on the piezoelectric film mounted on the front surface was measured by non-contact voltmeter. Measured electric potential distribution agreed well with that calculated by the FEM. The inverse method based on the least residual method was applied for estimating the location and size of crack from the measured electric potential distribution. It was shown that the passive electric potential CT method using piezoelectric film was useful for quantitative identification of back-surface three-dimensional crack.一般社団法人日本機械学会, 2002年, 材料力学部門講演会講演論文集, 2002, 497 - 498, 日本語
- Piezoelectric film is a sensing element that generates an electrical charge proportional to a change in mechanical stress. When the piezoelectric film is glued to the surface of a cracked material subjected to varying load, periodic change in distribution of electric potential is observed on the surface of piezoelectric film. Based on this phenomenon, the passive electric potential CT (computed tomography) method was developed for identifying two- and three-dimensional cracks. In the previous study, contact measurement method using electrodes and voltmeter was applied. In the present study, electric potential distribution is measured by non-contact voltmeter, which may be suitable for multi-point measurement, to develop non-contact electric potential CT measurement. It was found that the non-contact electric potential CT measurement had improved resolution and accuracy in crack identification.一般社団法人日本機械学会, 2001年, 材料力学部門講演会講演論文集, 2001, 177 - 178, 日本語
- 一般社団法人日本機械学会, 2000年, 材料力学部門講演会講演論文集, 2000, 315 - 316, 日本語
- 2023年11月, 高温強度シンポジウム前刷集, 61stポリカーボネートにおける疲労き裂発生過程の熱弾性温度解析
- 2023年, X線材料強度に関するシンポジウム講演論文集, 57th調和組織材料中の粗粒および微細粒における過剰転位密度の高輝度放射光を用いた回折コントラストトモグラフィーによる測定
- 2023年, 非破壊検査, 72(11) (11)5-8μm波長帯に感度を有する赤外線カメラを用いた建築物タイル外壁診断の精度向上
- 2023年, JSSC (Japanese Society of Steel Construction), (55) (55)鋼構造-THE NEXT STAGE 次世代への動き その3 維持管理・更新・改築 赤外線計測に基づく長大鋼橋梁の非破壊評価技術
- 2023年, 土木学会全国大会年次学術講演会(Web), 78thハイパースペクトルロックイン法による重防食塗装の劣化検知の高精度化
- 2023年, 高温強度シンポジウム前刷集, 61st高強度鋼を母材とするレーザ溶接継手の散逸エネルギ計測に基づく疲労強度評価
- 2023年, 高温強度シンポジウム前刷集, 61st熱弾性応力計測を用いた防食塗膜下のき裂に対する応力拡大係数評価
- 日本非破壊検査協会, 2022年09月, 非破壊検査 : Jjournal of the Japanese Society for Non-destructive Inspection / 日本非破壊検査協会 編, 71(9) (9), 422 - 428, 日本語建物外壁平面の赤外線計測におけるV-SLAMまたはSfMを利用した背景反射除去—Background Reflection Removal Using V-SLAM or SfM in the Infrared Measurement of Building Outer Wall Planes
- 日本建築防災協会, 2022年07月, 建築防災, (534) (534), 23 - 27, 日本語ドローン搭載外壁調査用赤外線サーモグラフィの開発と実証実験—特集 建築分野におけるドローン及び赤外線装置の活用(その1)
- 2022年, 日本材料学会学術講演会講演論文集(CD-ROM), 71stSCM435における散逸エネルギ計測に基づいた疲労限度推定
- 2022年, 疲労シンポジウム講演論文集, 35th赤外線サーモグラフィを用いたSCM435の散逸エネルギ計測およびそれに基づく疲労限度推定
- 2022年, 疲労シンポジウム講演論文集, 35th散逸エネルギ計測に基づいたAl合金FSW継手の疲労強度評価
- 2022年, 日本非破壊検査協会秋季講演大会講演概要集, 2022建物外壁の赤外線計測におけるV-SLAMを利用した背景反射除去
- Currently, the automobile industry is promoting weight reduction of car bodies by using high-strength thin steel sheets to improve fuel efficiency. On the other hand, since the rigidity of high-strength steel sheets alone is reduced, the weld bond method is attracting attention as a way to compensate for this. The weld bond method is a joining method that uses both adhesives and spot welding to improve the rigidity of steel plates while keeping them lightweight. The weld bond method can improve the rigidity only when the adhesive is applied to the required area. In this study, a new non-destructive inspection method using infrared thermography is developed as a high efficiency and high quality inspection method. The adhesive section is detected by measuring the difference in temperature fluctuation between the adhesive and non-adhesive section that occurs after heating the inspection target. However, the adhesive cannot be detected clearly with the time-series infrared data measured by temperature fluctuation. To solve this problem, we proposed PCA processing for time-series infrared data. The PCA process extracts each of the feature values present in the data as independent variables, and the changes in the feature values can be confirmed by images. It was found that the adhesive section, which cannot be confirmed by the infrared temperature image, can be clearly detected by the PCA processing.一般社団法人 日本機械学会, 2022年, 年次大会, 2022, J043-11, 日本語
- Application of heavy-duty anticorrosion coating is a typical method to prevent corrosion in steel bridges. It is required to repaint before coating deterioration becomes prominent because the anticorrosive performance of the coating decreases over a long term. Thus, it is important to develop a remote and nondestructive inspection method for the deterioration of coating of entire bridges at an early stage. This study proposed a new inspection method for the deterioration of the top coat of the heavy-duty anticorrosion coating by short-wave (SW) infrared spectral characteristics on the absorption and reflection. The remaining thickness of the coatings can be quantitatively evaluated by measuring the infrared reflected energy from the top coat because the absorption of the coating depends on the thickness. We measured the infrared reflected energy from the specimen consisting of various thicknesses of the top coat. Moreover, the infrared reflected energy for the in-service bridge cannot be ignored the effect of the reflections from the sea surface and the shadows of bridge members. Thus, we developed the measurement method independent of the lighting condition that combines the active infrared measurement with a halogen lamp and the lock-in processing that can extract only the fluctuating component of infrared intensity, thereby reducing the influence of disturbances. It was found that the remaining thickness of the top coat for the actual bridge in-service can be quantitatively evaluated based on active lock-in infrared measurement even in the artificially reproduced disturbance condition.一般社団法人 日本機械学会, 2022年, M&M材料力学カンファレンス, 2022, OS0125, 日本語
- In this study, basic research was conducted on a new lubricant analysis technique to constantly monitor the deterioration state of rotating equipment and other components in plant facilities. The research method used terahertz electromagnetic waves, which are electromagnetic waves in the frequency range of 0.1 to 10 THz, the boundary region between light and radio waves. As a measurement method, we focused on the fact that terahertz electromagnetic waves are safe for the human body yet have excellent transmittance, and conducted experiments using terahertz time-domain spectroscopy (THz-TDS). In this study, THz-TDS measurements were performed on artificially degraded lubricating oil to verify the possibility of detecting degradation factors and separately identifying each degradation factor. As a result, it was possible to detect water and iron powder and to identify them separately using the transmittance of THz electromagnetic waves obtained from the obtained time waveforms and the standard deviation ratio of the peak intensity values of THz waveforms. In addition, the detection and separation of iron powder, water, and antioxidants were possible using the attenuation of terahertz electromagnetic waves obtained from the frequency waveforms obtained by Fourier transforming the time waveforms. These results suggest that terahertz electromagnetic waves can be used to detect iron powder, water, and antioxidants, which are factors involved in lubricant degradation, and that each degradation factor can be separated and identified by using terahertz electromagnetic waves.一般社団法人 日本機械学会, 2022年, M&M材料力学カンファレンス, 2022, OS0130, 日本語
- In recent years, there has been a concern about the occurrence of gas leakage and fire accidents in plant facilities due to damage caused by aging deterioration of gas piping. However, conventional gas leakage source estimation methods require prior teacher data or calculated data of gas clouds to be compared, which requires large computation time and may not be applicable under unexpected circumstances. Therefore, this study proposes a method to estimate the source of gas leakage by visualizing the leaking gas cloud using an infrared camera and performing an inverse problem analysis based on the concentration information without the need for prior teacher data or calculation data. It is found that the leakage source can be estimated by retrospective search from the gas concentration distribution to the location where the infrared absorption is large. In addition, the leak source estimation is achieved with high accuracy by removing the initial search position data and using only the position data near the leak source in the retrospective search.一般社団法人 日本機械学会, 2022年, M&M材料力学カンファレンス, 2022, OS0128, 日本語
- In recent years, the development of car body structures using lightweight materials such as an aluminum alloy has progressed by taking into consideration environmental issues. Laser welding of aluminum alloys has been widely applied due to the commercialization of high-power fiber lasers. The application of welding techniques in actual structures requires a high level of safety and reliability. Thus, it is necessary to evaluate the fatigue fracture behaviors of the welds, which account for the majority of fractures. This study focused on the fatigue limit estimation method based on dissipated energy. The dissipated energy is a small heat generation caused by local plastic deformation. In recent years, the estimation method of fatigue limit by the dissipated energy is being considered for application in the industrial fields through the development of infrared sensors of high sensitivity and lock-in processing. This paper discussed the applicability of the estimation methods of the fatigue limit for the laser welds of aluminum alloys based on the dissipated energy measured using infrared thermography. The laser welds of aluminum alloys were fractured at the boundary between the weld metal and heat-affected zone. The fatigue limit of the laser welds was lower than that of the base metal specimen. In the measurement results of dissipated energy, the estimated fatigue limits of the laser welds and the base metal specimens were consistent with the fatigue limit by the fatigue tests. Thus, the fatigue limit of laser welds of aluminum alloys could be estimated by the dissipated energy.一般社団法人 日本機械学会, 2022年, M&M材料力学カンファレンス, 2022, OS0326, 日本語
- 2021年, 破壊力学シンポジウム講演論文集, 20th散逸エネルギー計測に基づいたき裂進展挙動の評価
- システム制御情報学会, 2019年05月22日, システム制御情報学会研究発表講演会講演論文集, 63, 531 - 533, 日本語赤外線計測による漏洩ガス広域検知システムの開発
- 日本光学会, 2017年08月, 光学 = Japanese journal of optics : publication of the Optical Society of Japan, 46(8) (8), 312 - 317, 日本語赤外線サーモグラフィーによる鋼橋の疲労亀裂検出技術 (インフラモニタリングへの光技術の貢献)
- 101 赤外線サーモグラフィを用いた熱弾性応力測定 : 微小部品の応力測定を目指して(FM2 実務に使えそうな最新の計測技術(1),研究討論セッション)Downsizing and cost reduction have been demanded to mechanical components. Simultaneously, material reliability for these components is also necessary. Thus corresponding evaluation techniques for these tasks are considerably required. For this reason, authors focused on a technique using infrared thermography, because it could evaluate not only stress concentration fields, but also fatigue crack initiation points owing to two-dimensional image. In this study, thermoelastic stress for the small size specimen was measured using infrared thermography with microscopic lens; hence the particular problems using microscopic lens were extracted and improved.一般社団法人日本機械学会, 2016年03月11日, 関西支部講演会講演論文集, 2016(91) (91), 1 - 4, 日本語
- 103 散逸エネルギ計測に基づいた疲労強度およびき裂発生位置の迅速推定(FM2 実務に使えそうな最新の計測技術(1),研究討論セッション)The evaluation of fatigue limit is important in designing products. In this study, the applicability of the fatigue limit estimation based on dissipated energy was investigated. The fatigue limit estimation and fatigue tests were carried out for the same specimen having multiple notches, and differences of dissipated energy in each notch and the crack initiated location were observed. It was found that the notch, where the biggest dissipated energy was observed, coincided with the crack initiated notch. Next, the fatigue limit estimation method was applied to the evaluation of pre-strained materials, and accuracy improvement of fatigue limit estimation was discussed. The fatigue limit can be estimated by increase rate of dissipated energy against stress level.一般社団法人日本機械学会, 2016年03月11日, 関西支部講演会講演論文集, 2016(91) (91), 7 - 10, 日本語
- 一般社団法人日本機械学会, 2016年03月11日, 関西支部講演会講演論文集, 2016(91) (91), 268 - 268, 日本語M316 高分子系複合材料の赤外線計測に基づく疲労損傷評価(GS3 材料力学(2),修士研究発表セッション)
- 一般社団法人日本機械学会, 2016年03月11日, 関西支部講演会講演論文集, 2016(91) (91), 266 - 266, 日本語M314 オーステナイト系ステンレス鋼における応力および散逸エネルギの顕微計測(GS3 材料力学(1),修士研究発表セッション)
- 一般社団法人日本機械学会, 2016年03月11日, 関西支部講演会講演論文集, 2016(91) (91), 273 - 273, 日本語M321 THz-TDSを用いた塗装膜下鋼板の健全性評価(GS3 材料力学(3),修士研究発表セッション)
- 一般社団法人日本機械学会, 2016年03月11日, 関西支部講演会講演論文集, 2016(91) (91), 242 - 242, 日本語M204 逆問題解析を用いた防食塗装膜下の応力測定(GS1,3 材料力学・計算力学(2),修士研究発表セッション)
- OS0408-335 テラヘルツ電磁波による欠陥イメージングに関する基礎検討THz electromagnetic wave has been receiving increasing attention in many engineering applications because of the following characteristics. THz wave transmits many kinds of materials except for metals and water. Materials have their own fingerprint absorption spectrum. THz wave is safe for human body. Especially the transmission property of THz wave enables us to develop nondestructive inspection technique for engineering plastics. In this study, fundamental study on defect imaging for Nylon resin sample with various shaped defects was conducted. Terahertz time-domain spectroscopy (THz-TDS) system was employed for the THz scanning imaging.一般社団法人日本機械学会, 2015年11月21日, M&M材料力学カンファレンス, 2015, "OS0408 - 335-1"-"OS0408-335-3", 日本語
- OS0403-415 マグネシウム合金AZ31Bにおける散逸エネルギ測定The fatigue limit of metal is dicided by 10^7 cycles fatigue test, and it takes long time and costs. Recently, fatigue limit estimation based on energy dissipation has been attracting. In this method, temperture change due to irreversible energy dissipation is measured by the infrared thermography for various levels of stress amplitude. In this study, this method was applied to extruded AZ31B magnesium alloy. It was found that harmonic vibration stress from fatigue testing machine affects the measurement of dissipated energy. This effect can be suppressed by adjustment of fatigue testing machine. New estimation scheme which is based on the incresing rate of dissipated energy was applied. The estimated fatigue limit obtained by the new estimation scheme coinceies with the compressive yield stress.一般社団法人日本機械学会, 2015年11月21日, M&M材料力学カンファレンス, 2015, "OS0403 - 415-1"-"OS0403-415-3", 日本語
- OS0804-301 高輝度放射光ラミノグラフィを用いた転動疲労き裂の発生および進展過程の観察In rolling contact fatigue (RCF), cracks initiate and propagate from inclusions beneath the surface. In the present study, crack propagation behavior under RCF was observed by synchrotron radiation computed laminography (SRCL), which is suitable for thin plates, in SPring-8 (Super Photon Ring-8 GeV). Specially fabricated inclusion-rich steel (modified JIS SUJ2) plate specimen, which includes extended inclusions distributed in depth direction, was employed in the experiments. Specimen with surface crack from inclusion and after the occurrence of flaking was observed by SRCL, and flaking defect and crack under the surface was successfully detected. It was found that the tensile-type vertical crack, which was perpendicular to the rolling contact surface, was formed from a cylindrical inclusion. After the vertical crack propagated along inclusion, the shear-type horizontal crack, which was parallel to the rolling contact surface, was found to initiate and then flaking occurred as the result of the propagation of the shear-type crack. It is considered that the vertical crack is an important factor of flaking process and crack propagation behavior under RCF from inclusions is clarified by SRCL.一般社団法人日本機械学会, 2015年11月21日, M&M材料力学カンファレンス, 2015, "OS0804 - 301-1"-"OS0804-301-2", 日本語
- GS0205-423 高輝度放射光によるステンレス鋼の疲労におけるミスオリエンテーション評価A three dimensional grain mapping technique for polycrystalline materials, called X-ray diffraction contrast tomography (DCT), was developed at SPring-8 (Super Photon ring-8 GeV), which is the brightest synchrotron radiation facility in Japan. To evaluate the fatigue damage of grains, total misorientation, β for each grain was calculated from DCT measurement. It is found that value of β increases with number of cycles, and change of β for primary slip plane is the largest in diffraction planes. In addition, the largest change of β, was observed in the diffraction plane with the largest Schmid factor, F_s in equivalent primary slip planes. From this results, it is found that change of β reflects slip behavior in a grain, because change of β correspond to Schmid factor in fcc materials which can be determined the primary slip direction.一般社団法人日本機械学会, 2015年11月21日, M&M材料力学カンファレンス, 2015, "GS0205 - 423-1"-"GS0205-423-3", 日本語
- 一般社団法人日本機械学会, 2015年10月04日, Abstracts of ATEM : International Conference on Advanced Technology in Experimental Mechanics : Asian Conference on Experimental Mechanics, 2015(14) (14), 112 - 112, 英語OS8-2 Fatigue Limit Estimation Based on Dissipated Energy for Pre-Strained Materials(Fatigue monitoring,OS8 Fatigue and fracture mechanics,STRENGTH OF MATERIALS)
- 一般社団法人日本機械学会, 2015年10月04日, Abstracts of ATEM : International Conference on Advanced Technology in Experimental Mechanics : Asian Conference on Experimental Mechanics, 2015(14) (14), 113 - 113, 英語OS8-3 Evaluation of High Cycle Fatigue Damage for Austenitic Stainless Steel by Diffraction Contrast Tomography Using Ultra-bright Synchrotron Radiation(Fatigue monitoring,OS8 Fatigue and fracture mechanics,STRENGTH OF MATERIALS)
- 一般社団法人日本機械学会, 2015年10月04日, Abstracts of ATEM : International Conference on Advanced Technology in Experimental Mechanics : Asian Conference on Experimental Mechanics, 2015(14) (14), 55 - 55, 英語OS4-13 Observation of Internal Small Fatigue Cracks in Ti-6Al-4V by Using Synchrotron Radiation Micro-computed Tomography Imaging at SPring-8(3D/4D image-based analyses and simulations 4,OS4 3D/4D image-based analyses and simulations,MEASUREMENT METHODS)
- 一般社団法人日本機械学会, 2015年10月04日, Abstracts of ATEM : International Conference on Advanced Technology in Experimental Mechanics : Asian Conference on Experimental Mechanics, 2015(14) (14), 54 - 54, 英語OS4-12 4D Observation of Crack Propagation Behavior under Rolling Contact Fatigue by Synchrotron Radiation Laminography(3D/4D image-based analyses and simulations 4,OS4 3D/4D image-based analyses and simulations,MEASUREMENT METHODS)
- 301 散逸エネルギに基づく疲労限度推定における推定メカニズムに関する検討(GS3 破壊解析・評価,研究討論セッション)Fatigue limit estimation based on the dissipated energy measurement using infrared thermography has been getting an increasing attention in various industries. In this study, mechanism of energy dissipation is investigated in relation with formulation of slip bands for JIS type 316L stainless steel through observation of slip bands by optical microscope and atomic force microscope. It was found that the energy dissipation was related to activity of slip band and estimated fatigue limit is corresponding to crack initiation stress level of the material. Phase information of energy dissipation was investigated and was applied to the accuracy improvement of dissipated energy measurement for fatigue damage estimation.一般社団法人日本機械学会, 2015年03月16日, 関西支部講演会講演論文集, 2015(90) (90), 59 - 62, 日本語
- 311 赤外線温度計測に基づく疲労き裂の非破壊評価(GS3 疲労・破壊(2),研究討論セッション)There is an urgent need for developing high-performance nondestructive evaluation (NDE) methods to assist in effective maintenance of aging infrastructures. Recently, use of infrared cameras in nondestructive testing has been attracting increasing interest, as they provide highly efficient remote and wide area measurements. This paper presents remote NDE techniques using infrared thermography developed by the authors for fatigue crack detection and structural integrity assessments.一般社団法人日本機械学会, 2015年03月16日, 関西支部講演会講演論文集, 2015(90) (90), 90 - 93, 日本語
- 一般社団法人日本機械学会, 2015年03月16日, 関西支部講演会講演論文集, 2015(90) (90), 277 - 277, 日本語M203 散逸エネルギ測定に基づくキャビテーション材の疲労限度予測(GS3 材料力学(1),修士研究発表セッション)
- 一般社団法人日本機械学会, 2015年03月16日, 関西支部講演会講演論文集, 2015(90) (90), 279 - 279, 日本語M205 熱弾性応力測定法に基づくき裂進展抑制効果の検証(GS3 材料力学(1),修士研究発表セッション)
- 一般社団法人日本機械学会, 2015年03月16日, 関西支部講演会講演論文集, 2015(90) (90), 281 - 281, 日本語M207 マグネシウム合金AZ31Bにおける散逸エネルギを用いた疲労限度推定(GS1,3,4 材料力学(2),修士研究発表セッション)
- 310 高輝度放射光の回折コントラストイメージングによる疲労過程中の転位構造変化の観察(GS3 疲労・破壊(2),研究討論セッション)The three dimensional grain mapping technique for polycrystalline material, called X-ray diffraction contrast tomography (DCT), was conducted in SPring-8 (Super Photon ring-8 GeV), which is the brightest synchrotron radiation facility in Japan, and the conditions of measurement and data processing procedure have been obtained. Developed technique was applied to a commercially pure iron, and an austenitic stainless steel. The shape and location of grain could be determined by DCT using the apparatus in a beam line of SPring-8. Total misorientation of an individual crystalographic plane of a specific grain during fatigue test of the steels were measured. In fatigue test of the stainless steel, thetotal misorientastion of {111} planes increased with number of cyccles. Among {111} planes, the amount of change depended on Schmid factor, i.e., the change was higher for planes with larger Schmid factor. For the commercially pure iron, the total misorientastion of {110} planes increased with number of cyccles. The amount of change, however, did not depend on Schmid factor because of pencile-glide. The effect of cross-slip should be considered一般社団法人日本機械学会, 2015年03月16日, 関西支部講演会講演論文集, 2015(90) (90), 86 - 89, 日本語
- 309 放射光ラミノグラフィを用いた転動疲労き裂進展の4D観察(GS3 疲労・破壊(2),研究討論セッション)In rolling contact fatigue(RCF), cracks are usually initiated from inclusions under the surface and propagated to the contact surface. In the present study, RCF cracks was observed using synchrotron radiation computed laminography(SRCL) in SPring-8. The specimen with flaking damage was measured by SRCL. It was found that two types of cracks, vertical crack and horizontal crack under the contact surface, which is typically rolling fatigue crack, was measured by SRCL. The ex-situ fatigue tests and SRCL observation was conducted in SPring-8. It was found that the horizontal crack initiated after the vertical crack initiated and propagated along inclusion. It is considered that the vertical crack is an important factor of flaking process, and the shape and length of inclusion affect the initiation and propagation of vertical crack.一般社団法人日本機械学会, 2015年03月16日, 関西支部講演会講演論文集, 2015(90) (90), 82 - 85, 日本語
- 一般社団法人日本機械学会, 2015年03月16日, 関西支部講演会講演論文集, 2015(90) (90), 377 - 377, 日本語M813 熱弾性応力計測に基づく橋梁の構造健全性評価(GS3,11 材料力学(10),修士研究発表セッション)
- 一般社団法人日本機械学会, 2015年03月16日, 関西支部講演会講演論文集, 2015(90) (90), 379 - 379, 日本語M815 パルス加熱赤外線サーモグラフィ法による防食塗装膜の潜在的劣化評価(GS3,11 材料力学(10),修士研究発表セッション)
- 逆問題解析を援用したコーティング下の応力計測に関する研究赤外線サーモグラフィを用いた熱弾性応力測定法によって鋼構造物の作用応力を計測する際,塗膜外面温度変動から鋼材表面の温度変動を逆解析的に推定することで塗膜を除去せずにき裂周辺の応力評価を行うことを検討した.一般社団法人日本機械学会, 2014年11月22日, 計算力学講演会講演論文集, 2014(27) (27), 277 - 278, 日本語
- OS2128 展伸Mg合金AZ31Bにおける散逸エネルギと変形機構との関係In recent years, fatigue limit estimation based on energy dissipation has been attracting considerable attention. In this method, temperature change due to irreversible energy dissipation is measured by infrared thermography in various levels of stress amplitude, under cyclic loading. It is experimentally observed that dissipated energy increases with increasing stress levels, and that there is a certain stress level where the dissipated energy undergoes a sharp increase, which has been proven to coincide with the fatigue limit in certain BCC and FCC metals. In this study, this method was applied to an HCP metal, AZ31B magnesium alloy. Fatigue limit estimation based on dissipated energy and conventional fatigue test are conducted on two types of AZ31B magnesium alloy; rolled and extruded material. The estimated fatigue limit obtained for rolled AZ31B agrees well with results from conventional fatigue tests, with fatigue strength at N=10^7. The dissipated energy showed the two characterisitic changes for the plastic strain energy. It was considered that these changes imply twinning and slip deformation restated to fatigue damage, respectively.一般社団法人日本機械学会, 2014年07月19日, M&M材料力学カンファレンス, 2014, "OS2128 - 1"-"OS2128-3", 日本語
- OS2125 ガラス短繊維複合材料における散逸エネルギ計測Recently, fatigue limit estimation based on the dissipated energy measurement using infrared thermography has attracted attention in various industries. In this study, dissipated energy measurement was applied to the evaluation of fatigue properties for composite material. The short glass fiber reinforced plastics, which is called BMC (Bulk Molding Compound) was used. In a staircase-like stress level test, dissipated energy increased with increase of stress level and there was a liner relationship between dissipated energy and energy loss caused by viscoelastic deformation. In constant stress level fatigue test, dissipated energy and thermoelastic temperature change showed the constant value in initial period of fatigue test, and then slightly decreased. On the other hand, energy loss increased with increase of loading cycles. It was considered that this deference between the change of dissipated energy and energy loss were due to the initiation of crack and fiber/matrix delamination. Therefore it was found that dissipated energy for BMC could evaluate plastic deformation of matrix and the condition of fiber/matrix interface.一般社団法人日本機械学会, 2014年07月19日, M&M材料力学カンファレンス, 2014, "OS2125 - 1"-"OS2125-3", 日本語
- OS2124 散逸エネルギの位相情報を用いた疲労損傷評価の改善Fatigue limit estimation based on the dissipated energy measurement using infrared thermography has been getting an increasing attention in various industries. Most of the studies on dissipated energy have been discussed based on the mean temperature rise or irreversible component of heat generation due to energy dissipation. In this study, phase information of energy dissipation was investigated and was applied to the accuracy improvement of dissipated energy measurement for fatigue damage estimation. The material under test is JIS type 316L austenitic stainless steel. The stress ratio R was set to be -1, -0.8 and -0.5. It is found that the phase difference takes certain constant value during significant energy dissipation and unique value corresponding to the stress ratio. It is concluded that band pass phase filtering is effective to the improvement of the measurement of dissipated energy.一般社団法人日本機械学会, 2014年07月19日, M&M材料力学カンファレンス, 2014, "OS2124 - 1"-"OS2124-3", 日本語
- OS2121 高輝度放射光ラミノグラフィを用いた高強度鋼中の転動疲労き裂の観察In rolling contact fatigue (RCF), cracks are usually initiated from inclusions under the surface and propagated to the contact surface. In the present study, RCF cracks was observed using synchrotron radiation computed laminography (SRCL) in SPring-8. For observation of crack propagation, ex situ rolling fatigue test and SRCL were applied to same sample. Laminography is suitable for the observation of sheeted material and sheeted sample is useful for operation of rolling fatigue tests. The specimen with flaking damage was measured by SRCL. It was found that two types of cracks, vertical crack and horizontal crack under the contact surface, which is typically rolling fatigue crack, can be measured by SRCL. For observation of RCF crack propagation, vertical crack which initiate from inclusion and propagated in the direction perpendicular to the contact surface, could be detected. SRCL and fatigue tests were conducted three times. As results, crack propagation could be observed between first and third measurements, while the different part of crack was detected in second measurement. Residual compression stress is considered to affect the observation of RCF crack. SRCL is concluded to be effective for evaluation of initiation and propagation behavior of crack in the rolling fatigue.一般社団法人日本機械学会, 2014年07月19日, M&M材料力学カンファレンス, 2014, "OS2121 - 1"-"OS2121-3", 日本語
- 一般社団法人日本機械学会, 2014年03月18日, 関西支部講演会講演論文集, 2014(89) (89), "3 - 24", 日本語315 展伸マグネシウム合金AZ31Bの散逸エネルギ計測による疲労限度評価(OS-4 マグネシウム合金の変形とメカニクス(4))
- 一般社団法人日本機械学会, 2014年03月18日, 関西支部講演会講演論文集, 2014(89) (89), "11 - 18", 日本語1118 ピエゾセンサシートおよび逆問題解析を用いた接触センシングの開発(GS-3 材料構造・変形解析(1))
- 一般社団法人日本機械学会, 2014年03月18日, 関西支部講演会講演論文集, 2014(89) (89), "11 - 24", 日本語1125 高感度磁気センサを用いた渦電流探傷システムによる深部欠陥の検出に関する研究(GS-3 材料構造・変形解析(2))
- 一般社団法人日本機械学会, 2014年03月18日, 関西支部講演会講演論文集, 2014(89) (89), "11 - 25", 日本語1126 熱弾性応力分布測定に基づく破壊力学パラメータ評価に関する研究(GS-3 材料構造・変形解析(2))
- OS1504 放射光μCT及び小型転動疲労試験機を用いた転動疲労き裂進展過程の観察In rolling contact fatigue (RCF), cracks are usually initiated from inclusions under the surface and propagated to the surface. In the present study, the micro computed tomography (μCT) imaging and laminography using synchrotron radiation in SPring-8 is applied for observation of RCF cracks. The compact RCF testing machine is developed to observe RCF crack behavior m-situ. In this testing machine, the steel ball rolls on the specimen, linearly and reciprocally, and a specimen can be attached and removed easily. Since the size of the sample for μCT imaging has to be limited by penetrative power, the sample for μCT imaging has 500μm×500μm cross-section. On the other hand, laminography can be applied to a sheeted material. The sample, where an artificial defect is introduced, is used for observation of crack initiation and propagation. It is found from this experiment that cracks initiate and propagate in the depth direction along the artificial hole with increasing the number of cycles. Flaking and RCF crack in sheeted sample are observed by laminography. RCF cracks which initiate and propagate under contact surface can be detected. The shape and location observed by laminography coincide with that by SEM.一般社団法人日本機械学会, 2013年10月12日, M&M材料力学カンファレンス, 2013, "OS1504 - 1"-"OS1504-3", 日本語
- OS1524 α黄銅超微細結晶粒材の疲労強度Tensile tests and fatigue tests were conducted with a α-brass ultra-fine grains (UFG) from 1 to 5μm diameter produced either by severe plastic deformation through equal angular pressing (ECAP) or multiple rolling, where the minimum grain size obtained by ECAP was 4.9 μm, and 1.0 μm by the multiple rolling. The proof stress, tensile strength and fatigue limit were increased with decreasing grain size, and Hall-Petch relationships were established. The relationship, however, depended on the thickness of specimen, i.e., those were lower for thin plate. The proof stress increased by ten-fold by the grain refinement, while the tensile strength increased by two-fold. The fatigue strength also increased; however, the effect was not as much as the static strengths.一般社団法人日本機械学会, 2013年10月12日, M&M材料力学カンファレンス, 2013, "OS1524 - 1"-"OS1524-2", 日本語
- OS1309 散逸エネルギ計測に基づく展伸マグネシウム合金の疲労限度評価In recent years, fatigue limit estimation based on dissipated energy measurement using infrared thermography has attracted attention in various industries. In this study, fatigue limit estimation based on dissipated energy measurement and conventional fatigue test were conducted the expanded-magnesium alloy type AZ31B. Fatigue limit estimated by dissipated energy measurement was around 95MP to lOOMPa. This value generally coincided with that obtained by conventional 10^7 cycles fatigue test. Relationship between plastic strain energy and dissipated energy was investigated to discuss microstructure transformation. It was found that dissipated energy does not vary linearly with the plastic strain energy. It was considered that energy dissipation for AZ31B is affected by the deformation twins.一般社団法人日本機械学会, 2013年10月12日, M&M材料力学カンファレンス, 2013, "OS1309 - 1"-"OS1309-3", 日本語
- OS1503 高輝度放射光を用いた回折コントラストトモグラフィによる疲労損傷評価に関する検討X-ray diffraction contrast tomography (DCT) is a technique for three-dimensional grain mapping of polycrystalline material. Measurement of DCT has been conducted m SPring-8 and shape and location of grain can be determined by DCT technique using the apparatus in BL19B2. For evaluation of plastic deformation by DCT, tensile and cyclic loading was applied to the sample during the measurement of DCT. The diffraction spots belonging to certain grain appear over some continuous projection images. The rotation angle range where diffraction spot appear is defined as grain orientation spread, and the grain orientation spread was counted in tensile tests and fatigue test. In the tensile test, the grain orientation spread increases in the plastic deformation. In the fatigue test, grain orientation spread increases with increasing m the number of cycles. It is possible to evaluate fatigue damage by DCT technique and using the grain orientation spread.一般社団法人日本機械学会, 2013年10月12日, M&M材料力学カンファレンス, 2013, "OS1503 - 1"-"OS1503-3", 日本語
- OS0611 SUS316L鋼表面改質材の散逸エネルギ計測こよる疲労限度評価Recently, fatigue limit estimation based on the dissipated energy measurement using infrared thermography has attracted attention in various industries. In this study, fatigue limit estimation based on dissipated energy measurement was applied to the evaluation of shot peening treatment. Shot peening treatment is used for fatigue limit improvement by applying work hardening layer and compressive residual stress. The strength of material is affected strongly by shot peening treatment condition. Therefore, it is useful to evaluate the effect of shot peening condition by fatigue limit estimation. The fatigue limit estimation by energy dissipation was applied to shot peened 316L stainless steel specimen. It is found that estimated fatigue limit of the shot peened material obtained by dissipated energy is conservative value compared with that obtained by conventional fatigue test. After the fatigue test, micro cracks were observed in the unbroken specimen of shot peened materials. Therefore, dissipated energy for shot peened materials subjected to the stress amplitude below fatigue limit was affected by non-propagation cracks. It was considered that the estimated fatigue limit indicated crack initiation stress level.一般社団法人日本機械学会, 2013年10月12日, M&M材料力学カンファレンス, 2013, "OS0611 - 1"-"OS0611-3", 日本語
- 一般社団法人日本機械学会, 2013年03月16日, 関西支部講演会講演論文集, 2013(88) (88), "5 - 21", 日本語521 黄銅超微細結晶粒材作製法の開発とその強度評価(GS-3,4 強度評価・疲労(2))
- 一般社団法人日本機械学会, 2013年03月16日, 関西支部講演会講演論文集, 2013(88) (88), "4 - 29", 日本語429 高輝度放射光による三次元結晶マッピング法を用いた多結晶金属組織観察(GS-1,3 計算力学(4))
- 一般社団法人日本機械学会, 2013年03月16日, 関西支部講演会講演論文集, 2013(88) (88), "5 - 14", 日本語514 オーステナイト系ステンレス鋼における疲労限度の簡易予測法(GS-3,4 強度評価・疲労(1))
- 一般社団法人日本機械学会, 2013年03月16日, 関西支部講演会講演論文集, 2013(88) (88), "10 - 5", 日本語1022 放射光μCTイメージモデルに基づいた有限要素解析によるねじり疲労き裂進展挙動の評価(GS-2 CT・イメージング)
- OS0723 散逸エネルギ計測に基づく複数切欠き試験片に対する疲労限度予測The evaluation of the fatigue limit is important in designing products. Fatigue limit estimation based on dissipated energy has been getting considerable attentions. In this method, temperature change due to irreversible energy dissipation is measured by infrared thermography for various levels of stress amplitude. It is known that the dissipated energy increases with increasing stress levels, and a certain stress level where the change in dissipated energy shows sharp increase coincides with fatigue limit. In this study, this technique was applied to the detection of crack initiation location. The fatigue limit estimation and fatigue tests were carried out for the specimen having multiple notches. It was found that the increasing rate of dissipated energy measured at the notch where crack was initiated was larger than that at other notches. Therefore, it was considered that the location of crack could be detected before crack initiation by using dissipated energy measurement.一般社団法人日本機械学会, 2012年09月22日, M&M材料力学カンファレンス, 2012, "OS0723 - 1"-"OS0723-3", 日本語
- 一般社団法人日本機械学会, 2012年03月16日, 関西支部講演会講演論文集, 2012(87) (87), "8 - 22", 日本語822 高感度MIセンサを用いた漏洩および渦電流式欠陥検出法の開発(GS-3 き裂検出,固定)
- 一般社団法人日本機械学会, 2012年03月16日, 関西支部講演会講演論文集, 2012(87) (87), "8 - 26", 日本語826 高分子ピエゾセンサシートを用いた逆問題的計測手法に関する研究(GS-3 き裂検出,固定)
- 一般社団法人日本機械学会, 2012年03月16日, 関西支部講演会講演論文集, 2012(87) (87), "8 - 21", 日本語821 放射光μCTを用いた高強度鋼における転動疲労下のき裂観察(GS-3 金属ガラス,放射光観察)
- 一般社団法人日本機械学会, 2012年03月16日, 関西支部講演会講演論文集, 2012(87) (87), "8 - 20", 日本語820 高輝度放射光の回折コントラストイメージを用いた三次元結晶マッピング法(GS-3 金属ガラス,放射光観察)
- 2012年02月, 平成23年度 SPring-8 重点産業利用課題成果報告書(2011A), pp.173-176, 日本語高強度鋼の転動疲労下のはく離損傷および内部き裂形態の観察[査読有り]その他
- 2012年02月, 平成23年度 SPring-8 重点産業利用課題成果報告書(2011A), pp.169-172, 日本語結晶3Dマッピング法を用いた塑性ひずみの測定[査読有り]その他
- 日本材料学会, 2012年, 学術講演会講演論文集, 61, 455 - 456, 日本語735 結晶3Dマッピング法による塑性ひずみ評価法の開発(疲労損傷,疲労損傷観察ならびに強度評価,オーガナイスドセッション1)
- 日本材料学会, 2012年, 学術講演会講演論文集, 61, 27 - 28, 日本語114 オーステナイト系ステンレス鋼の散逸エネルギ計測に基づく疲労限度予測に及ぼすマルテンサイト変態の影響(非破壊検査,破壊の発生・進展とその解析・評価・計測,オーガナイスドセッション7)
- 一般社団法人日本機械学会, 2011年09月19日, Abstracts of ATEM : International Conference on Advanced Technology in Experimental Mechanics : Asian Conference on Experimental Mechanics, 2011(10) (10), "OS05 - 4-3-1", 英語OS05-4-3 Observation of Delamination Defects and Cracks in High-strength Steels under Rolling Contact Fatigue by SR Micro CT Imaging
- 一般社団法人日本機械学会, 2011年09月19日, Abstracts of ATEM : International Conference on Advanced Technology in Experimental Mechanics : Asian Conference on Experimental Mechanics, 2011(10) (10), "OS05 - 1-2-1", 英語OS05-1-2 Evaluation of Torsional Fatigue Crack Propagation by Shinchrotoron Radiation Micro-CT Imaging
- 一般社団法人日本機械学会, 2011年09月19日, Abstracts of ATEM : International Conference on Advanced Technology in Experimental Mechanics : Asian Conference on Experimental Mechanics, 2011(10) (10), "OS05 - 2-3-1", 英語OS05-2-3 Development of Three-dimensional Grain Mapping Technique Using SPring-8
- OS0315 散逸エネルギ評価法によるSUS304鋼の疲労限度推定の測定条件に関する検討(OS3-3 AE・超音波・赤外線,OS-3 非破壊評価と構造モニタリング1)In recent years, fatigue limit estimation method based on energy dissipation measured by infrared thermography is getting an increasing attention. In this method, temperature change due to irreversible energy dissipation during one loading cycle is measured for different levels of applied stress amplitude. Obtained relationship between temperature change and stress amplitude shows a significant inflection at certain stress level where temperature change due to energy dissipation shows steep increase. It is known that this stress level coincides with fatigue limit. In this study, measurement conditions for appropriate fatigue limit determination based on the energy dissipation are discussed in conjunction with (i) required number of loading cycles in each stress level, (ii) representative value in measurement area, and (iii) influence of loading history and fatigue damage accumulation.一般社団法人日本機械学会, 2011年07月16日, M&M材料力学カンファレンス, 2011, "OS0315 - 1"-"OS0315-3", 日本語
- OS0509 放射光μCTを用いた高強度鋼の転動疲労下のき裂検出(OS5-2 き裂進展・計測,OS-5 材料の疲労挙動と損傷評価1)In the present study, synchrotron radiation micro computed tomography (SR μCT) imaging of SPring-8 was applied to the observation of delamination defects in high-strength steels under rolling contact fatigue. The rolling contact fatigue crack initiation occurs under surface and these defects propagate to the surface. The conventional technique, such as optical microscope and scanning microscope, cannot give us the crack initiation and growth behavior under the surface. Therefore, the shape of rolling contact fatigue defects was observed by SR μCT imaging. The specimen with an artificial defect, which simulates an inclusion, was used to the contact rolling fatigue tests. The broken and non-broken specimens were observed respectively by SR μCT. The delamination defects and cracks can be detected from the artificial defetct. It is found from these results that the defect initiation and propagation behavior in the rolling contact fatigue process can be discussed from the measurements by SR μCT imaging. The number of crack, location and size of crack obtained by the CT imaging coincide with those by polishing and SEM measurements. It is found from these results that the defect initiation and propagation behavior in the rolling contact fatigue process can be discussed from the measurements by SR μCT imaging.一般社団法人日本機械学会, 2011年07月16日, M&M材料力学カンファレンス, 2011, "OS0509 - 1"-"OS0509-3", 日本語
- OS0513 SUS304鋼の応力誘起マルテンサイト変態を利用した疲労損傷評価(OS5-3 疲労損傷,OS-5 材料の疲労挙動と損傷評価1)SUS304 steel is a kind of the austenitic stainless steel. It is used for various fields, example for the plant and the nuclear plant. The austenite phase is non-magnetism usually, but when SUS304 steel is received a big stress, a part of it is transformed into the martensitic phase that is ferromagnetism. In recently years, a lot of researches are done the nondestructive testing by measuring the magnetic characteri6stic using this character. It is hope that the method of detecting the damage before generation of the crack for to improve the safety of the machine and the structure. Then, we measured martensite fraction in the fatigue process of SUS304 steel, and we examined applicability from the change in martensite fraction to the fatigue damage evaluation in this study.一般社団法人日本機械学会, 2011年07月16日, M&M材料力学カンファレンス, 2011, "OS0513 - 1"-"OS0513-3", 日本語
- 一般社団法人日本機械学会, 2011年03月19日, 関西支部講演会講演論文集, 2011(86) (86), "6 - 4", 日本語604 散逸エネルギ計測に基づく疲労損傷過程の評価(GS-3 疲労(2))
- 一般社団法人日本機械学会, 2011年03月19日, 関西支部講演会講演論文集, 2011(86) (86), "6 - 8", 日本語608 オーステナイト系ステンレス鋼の疲労損傷過程における加工誘起マルテンサイト変態挙動の観察と評価(GS-3破壊力学・材料じん性)
- 一般社団法人日本機械学会, 2011年03月19日, 関西支部講演会講演論文集, 2011(86) (86), "6 - 11", 日本語611 放射光μCTイメージングを用いたねじり疲労き裂進展挙動の観察と評価(GS-3破壊力学・材料じん性)
- 日本材料学会, 2011年, 学術講演会講演論文集, 60, 97 - 98, 日本語111 高輝度放射光CTによるねじり疲労き裂の進展・分岐挙動の観察と評価(き裂進展,疲労挙動と予寿命評価,オーガナイスドセッション1)
- 508 回折コントラストイメージを用いた結晶構造解析(OS5-2 回折法による材料評価)The novel technique for non-destructive and simultaneous mapping of the three-dimensional grain and the absorption microsiructure of material was developed. This technique is formed X-ray diffraction contrast tomography, and it shares a common experimental setup with conventional X-ray absorption contrast tomography. The grain are imaged using the occasionally occurring diffraction contribution to the X-ray attenuation coefficient each time a grain fulfills the diffraction condition The three-dimensional grain shapes are reconstructed from a limited number of projections using an algebraic reconstruction technique. The crystallographic grain orientation can be determined from the sets of diffraction contrast image. The measurements of diffraction contrast were carried out in SPring-8, which is large synchrotron radiation facility in Japan. The conditions for measurement of diffraction contrast image were investigated and the potential of this technique were discussed in this paper.一般社団法人日本機械学会, 2010年10月09日, M&M材料力学カンファレンス, 2010, 343 - 345, 日本語
- 2010年09月, 平成21年度 Spring-8重点産業利用課題成果報告書2009B, pp.97-100, 日本語クリープ損傷評価のための結晶3Dマッピング法の開発その他
- 日本工業出版, 2010年08月, 検査技術, Vol. 15, No. 8, pp.1-7(8) (8), 1 - 7, 日本語高輝度放射光CT法による腐食疲労損傷の発生と成長の観察記事・総説・解説・論説等(学術雑誌)
- 2010年03月, 平成21年度Spring-8重点産業利用課題成果報告書2009A, pp.168-170, 日本語金属材料における疲労き裂進展モード遷移条件の解明その他
- 日本材料学会, 2010年, 学術講演会講演論文集, 59, 125 - 126, 日本語411 回折コントラストイメージを用いた結晶構造解析手法の開発(材料の組織・構造と疲労特性I,疲労研究の課題と展望,オーガナイスドセッション1)
- 2009年12月, 非破壊検査, Vol.58, No.10, pp.446-451, 日本語高輝度放射光CT法による腐食疲労損傷の観察[査読有り]記事・総説・解説・論説等(学術雑誌)
- OS1207 放射光μCTイメージングを用いた腐食疲労損傷の観察(X線,放射光,中性子による材料・材料強度評価,オーガナイズドセッション)Pitting corrosion of aluminum alloy serve as nuclei for subsequent fatigue cracking and significantly reduce the serviceable life of structure. In the present study, Micro computed tomography (μCT) with synchrotron radiation of SPring-8 was applied to observe and evaluate the corrosion and corrosion fatigue of aluminum alloy. The compact corrosion fatigue testing machine was developed for flitigue testing by the side of a beam line of SPring-8. The growth of pitting corrosion could be observed nondestructively by using SR CT imaging. It was found that pitting corrosion results from the interactions of the matrix with clusters of particles and inclusions. The growth of pits proceeds inside specimen in the early stage.一般社団法人日本機械学会, 2009年07月24日, M&M材料力学カンファレンス, 2009, 658 - 659, 日本語
- OS0724 オーステナイト系ステンレス鋼の疲労損傷によるマルテンサイト変態挙動の観察(構造用材料の疲労挙動と寿命評価,オーガナイズドセッション)The behavior of the defonnation-induced martensitic transformation in austenitic stainless steels was investigated under monotonic and cyclic loading. The volume fraction of martensitic phase was measured by ferrite scope in the tensile test and the axial fatigue tests. It was found that the martensitic volume fraction ζ, was not detected in early stage of fatigue process under cyclic loading below yield stress that was measured by the tensile test, and ζ increased with increasing in number of cycles. The behavior of martensitic transformation under cyclic deformation agree with the behavior of plastic strain such as cyclic softening and cyclic hardening. The process of martensite transformation can be represented as function of the cumulative plastic strain and the cumulative strain-energy density.一般社団法人日本機械学会, 2009年07月24日, M&M材料力学カンファレンス, 2009, 516 - 517, 日本語
- 一般社団法人日本機械学会, 2009年03月16日, 関西支部講演会講演論文集, 2009(84) (84), "8 - 23", 日本語823 高温超電導SQUID顕微鏡を用いた非破壊評価法の開発(GS-3 計測・検査(2))
- 日本材料学会, 2009年, 学術講演会講演論文集, 58, 151 - 152, 日本語702 放射光マイクロCTイメージングによるねじり疲労き裂の観察(疲労過程における観察と計測,疲労損傷の機構解明と評価,オーガナイスドセッション1)
- 一般社団法人日本機械学会, 2008年09月16日, M&M材料力学カンファレンス, 2008, "OS0123 - 1"-"OS0123-2", 日本語OS0123 高温SQUIDを用いたプリント配線の非破壊欠陥検出(非破壊評価と構造モニタリング(3))
- 一般社団法人日本機械学会, 2008年09月16日, M&M材料力学カンファレンス, 2008, "OS0122 - 1"-"OS0122-2", 日本語OS0122 オーステナイト系ステンレス鋼の繰返し変形による磁気特性変化に及ぼす応力比の影響(非破壊評価と構造モニタリング(3))
- 一般社団法人日本機械学会, 2008年03月14日, 関西支部講演会講演論文集, 2008(83) (83), "9 - 3", 日本語903 SQUIDを用いたプリント配線の非破壊欠陥検出法の開発(GS-3 検査・評価(1))
- 2008年03月, 2007年度大学研究助成技術研究報告書,財団法人JFE21世紀財団, pp.107-112, 日本語高輝度放射光CT法による鉄鋼材料の超長寿命域における疲労破壊機構の解明記事・総説・解説・論説等(学術雑誌)
- 日本材料学会, 2008年, 学術講演会講演論文集, 57, 79 - 80, 日本語316 SUS304鋼の疲労損傷による磁気特性変化に及ぼす応力比の影響(計測・評価技術,破壊の発生・進展とその解析・評価・計測,オーガナイスドセッション7)
- 2008年, 平成20年度Spring-8重点産業利用課題成果報告書2008A, pp.73-75, 日本語超長寿命域における鋼中の疲労損傷の観察その他
- 日本材料学会, 2007年, 学術講演会講演論文集, 56, 91 - 92, 日本語412 SUS304鋼のき裂発生過程における磁気特性変化の観察(破壊特微量・影響因子の抽出,オーガナイズドセッション8.破壊の発生・進展とその解析・評価・計測)
- 一般社団法人日本機械学会, 2006年03月17日, 関西支部講演会講演論文集, 2006(81) (81), "11 - 9", 日本語1109 SUS304鋼の疲労過程における磁気特性変化の観察(GS-3,4 材料の疲労)
- 2006年03月, 平成17年度SPring-8トライアルユース成果報告書, pp.80-83, 日本語放射光CTイメージングを用いた高強度鋼中の疲労き裂の検出および定量的評価[査読有り]その他
- 2006年03月, 平成17年度SPring-8トライアルユース成果報告書, pp.48-52, 日本語放射光CTイメージングを用いた高強度鋼中の介在物の検出および定量的評価その他
- 日本材料学会, 2006年, 学術講演会講演論文集, 55, 269 - 270, 日本語318 SUS304鋼における疲労過程の磁気特性変化(疲労の検出・評価・抑止I,疲労における機構と評価,オーガナイズドセッション1)
- 日本機械学会, 2005年, 材料力学部門春のシンポジウム講演論文集, 2005, 89 - 92, 日本語210 受動型電気ポテンシャルCT法によるき裂同定および欠陥モニタリング(セッション8)
- 日本材料学会, 2005年, 学術講演会講演論文集, 54, 225 - 226, 日本語119 SUS304鋼における疲労損傷の磁気力顕微鏡による観察(微視組織と疲労強度評価II, 疲労の実際と最新の話題 微視組織と疲労強度評価)
- 一般社団法人日本機械学会, 2004年12月15日, 評価・診断に関するシンポジウム講演論文集, 2004(3) (3), 73 - 78, 日本語受動型電気ポテンシャルCT法による複合材内はく離状欠陥の同定およびモニタリング
- 817 複合材料におけるはく離欠陥同定に対する受動型電気ポテンシャルCT法の適用性(GS-3 可視化計測)The passive electric potential CT (computed tomography) method using piezoelectric material have been developed as a health monitoring technique. In this method, piezoelectric film is glued on the surface of a strucrure subjected to external load. Electric potential distribution on the piezoelectric film changes due to the stain distribution on the surface of the structure. If the structure has defects, the stain distribution induces charactristic electric potential distribution, which can be used for the defect identification. In this study, the passive electric potential CT method was applied to laminated composite for the identification of three-dimensional delamination defect. Electric potential distribution on piezoelectric film was caluculated by the finite element method. It was found that electric potential distribution show a charactristic change due to the location, size, and depth of the delamination.一般社団法人日本機械学会, 2004年03月17日, 関西支部講演会講演論文集, 2004(79) (79), "8 - 31"-"8-32", 日本語
- 一般社団法人日本機械学会, 2003年11月22日, 計算力学講演会講演論文集, 2003(16) (16), 645 - 646, 日本語727 受動型電気ポテンシャル CT 法による複数き裂の同定とその破壊力学的評価
- 能動型および受動型電気ポテンシャルCT法によるき裂同定(<特集>逆問題)The active and passive electric potential CT (Computed Tomography) methods for crack identification using the inverse analyses are described. For the active method, which requires applications of electric current, the inverse methods were constructed based on the boundary element method. Examples of the application of the passive electric potential CT method demonstrated the applicability of the method. The passive method, which does not require the application of the electric current, can be constructed by gluing piezoelectric film on the surface of a cracked structure subjected to mechanical load. The inverse method for crack identification is constructed by applying the finite element method, which takes into account the interaction between the strain field and the electric field. The applicability of the passive method is demonstrated by experimental and numerical investigations. Comparison between the active and the passive methods is made.日本AEM学会, 2003年06月10日, 日本AEM学会誌 = Journal of the Japan Society of Applied Electromagnetics, 11(2) (2), 73 - 81, 日本語
- 一般社団法人日本機械学会, 2002年12月03日, 評価・診断に関するシンポジウム講演論文集, 2002(1) (1), 96 - 101, 日本語207 リアルタイムモニタリングのためのピエゾ材料を用いた受動型電気ポテンシャル CT 法によるき裂同定
- 一般社団法人日本機械学会, 2002年10月30日, 計算力学講演会講演論文集, 2002(15) (15), 411 - 412, 日本語436 ピエゾ材料を用いた受動型電気ポテンシャル CT 法による複合材内はく離状欠陥の同定
- 日本機械学会, 2002年, M&Mレイクサイドサマーシンポジウム講演論文集, 2002, 97 - 100, 日本語30 ピエゾ材料を用いた受動型電気ポテンシャル CT 法によるき裂同定
- 213 受動型電気ポテンシャル CT 法による裏面 3 次元き裂の同定に関する実験的検討When a piezoelectric film is glued on the surface of a cracked material subjected to load, change in distribution of electric potential is observed on the surface of piezoelectric film. Based on this phenomenon, the passive electric potential CT (computed tomography) method was developed for identifying two- and three-dimensional cracks. In this study, this method was experimentally applied to identify three-dimensional crack opening on the back surface. Electric potential distribution on the piezoelectric film mounted on the front surface was measured by non-contact voltmeter. Measured electric potential distribution agreed well with that calculated by FEM. The inverse method based on the least residual method was applied for estimating the location and size of crack from measured electric potential distribution. It was shown that the passive electric potential CT method using piezoelectric film was useful for quantitative identification for back-surface three-dimensional crack.一般社団法人日本機械学会, 2002年, 関西支部講演会講演論文集, 2002(77) (77), "2 - 39"-"2-40", 日本語
- 日本材料学会, 2002年, 学術講演会講演論文集, 51, 43 - 44, 日本語207 複合材料におけるはく離欠陥同定に対する受動型電気ポテンシャル CT 法の適用性に関する数値的検討
- 237 試験片表面に貼付したピエゾ薄膜の計測結果を用いた受動型電気ポテンシャルCT法による裏面き裂の同定(OS09-1 逆問題解析手法の開発と最新応用(1))(OS09 逆問題解析手法の開発と最新応用)When the piezoelectric film is glued on the surface of a cracked material subjected to mechanical load, change in distribution of electric potential is observed on the surface of piezoelectric film. Based on this phenomenon, passive electric potential CT(computed tomography) method was developed for the identification of two- and three-dimensional cracks based on the FEM inverse analysis. In this paper, this method was applied to identify 3-D surface crack opening on the back surface. Numerical simulations were carried out on determination of location and size of back surface crack. It was found that crack parameters were identified within the error of 1.0%, when the noise level of observed electric potential distribution was lower than 0.1%.一般社団法人日本機械学会, 2001年11月27日, 計算力学講演会講演論文集, 2001(14) (14), 197 - 198, 日本語
■ 講演・口頭発表等
- 日本機械学会関西学生会 2018年度学生員卒業研究発表講演会, 2019年03月, 日本語, 日本機械学会, 滋賀県草津市, 国内会議放射光回折コントラストトモグラフィによる調和組織ステンレス鋼の転位密度評価口頭発表(一般)
- 日本機械学会関西学生会卒業研究発表講演会, 2019年03月, 日本語, 日本機械学会, 草津市・立命館大学, 国内会議熱弾性応力および散逸エネルギ計測に及ぼす防食塗装膜の影響口頭発表(一般)
- 日本機械学会関西学生会卒業研究発表講演会, 2019年03月, 日本語, 日本機械学会, 草津市・立命館大学, 国内会議赤外線計測によるガス検知法の開発口頭発表(一般)
- 日本機械学会関西学生会卒業研究発表講演会, 2019年03月, 日本語, 日本機械学会, 草津市・立命館大学, 国内会議赤外線サーモグラフィを用いた熱弾性応力計測によるき裂進展性評価口頭発表(一般)
- 日本機械学会関西学生会卒業研究発表講演会, 2019年03月, 日本語, 日本機械学会, 草津市・立命館大学, 国内会議散逸エネルギ計測に基づくアルミ合金材料A5052の疲労強度推定口頭発表(一般)
- 日本機械学会関西学生会卒業研究発表講演会, 2019年03月, 日本語, 日本機械学会, 草津市・立命館大学, 国内会議散逸エネルギ計測に基づくFSWに対する疲労限度推定口頭発表(一般)
- 日本機械学会関西支部第94期定時総会講演会, 2019年03月, 日本語, 日本機械学会, 草津市・立命館大学, 国内会議散逸エネルギ計測に基づくFSWに対する疲労強度評価口頭発表(一般)
- 日本機械学会関西学生会 2018年度学生員卒業研究発表講演会, 2019年03月, 日本語, 日本機械学会, 滋賀県草津市, 国内会議高輝度放射光ラミノグラフィによる非金属介在物起点の転動疲労き裂発生および進展過程の観察口頭発表(一般)
- 日本機械学会関西学生会卒業研究発表講演会, 2019年03月, 日本語, 日本機械学会, 草津市・立命館大学, 国内会議近赤外線カメラを用いた防食塗膜最表面の劣化の広域検出口頭発表(一般)
- 日本機械学会関西学生会卒業研究発表講演会, 2019年03月, 日本語, 日本機械学会, 草津市・立命館大学, 国内会議テラヘルツ電磁波を用いたGFRP内部欠陥の検出口頭発表(一般)
- 3rd International Symposium on Hetero Structure and Advanced Materials, 2019年03月, 英語, 立命館大学, 滋賀県草津市, 国内会議Evaluation of Fatigue Properties and Fatigue Crack Propagation in Bimodal Harmonic Structured Austenitic Stainless Steel[招待有り]口頭発表(招待・特別)
- 日本機械学会関西学生会卒業研究発表講演会, 2019年03月, 日本語, 日本機械学会, 草津市・立命館大学, 国内会議5-8μm波長帯赤外線サーモグラフィを用いた構造物外壁検査に関する研究口頭発表(一般)
- 日本機械学会 M&M2018 材料力学カンファレンス, 2018年12月, 日本語, 日本機械学会, 福井県福井市, 国内会議放射光回折コントラストトモグラフィーによるマグネシウム合金 AZ31 の引張-圧縮過程における変形挙動の観察口頭発表(一般)
- 日本機械学会M&M2018材料力学カンファレンス, 2018年12月, 日本語, 日本機械学会, 福井市・福井大学, 国内会議赤外線応力計測による鋼橋梁部材の疲労き裂進展性評価と補修効果検証口頭発表(一般)
- 日本機械学会M&M2018材料力学カンファレンス, 2018年12月, 日本語, 日本機械学会, 福井市・福井大学, 国内会議光学―赤外線同期計測による位置補正画像処理を援用した熱弾性応力および散逸エネルギ計測の高精度化口頭発表(一般)
- 日本機械学会M&M2018材料力学カンファレンス, 2018年12月, 日本語, 日本機械学会, 福井市・福井大学, 国内会議近赤外線計測による防食塗装膜劣化の定量評価口頭発表(一般)
- 日本機械学会M&M2018材料力学カンファレンス, 2018年12月, 日本語, 日本機械学会, 福井市・福井大学, 国内会議5-8μm波長帯赤外線サーモグラフィを用いた構造物外壁検査に関する研究口頭発表(一般)
- 日本材料学会第34回 疲労シンポジウム講演論文集, 2018年10月, 日本語, 日本材料学会, 京都府京都市, 国内会議高輝度放射光ラミノグラフィによる軸受鋼の転動疲労き裂進展挙動に及ぼす非金属介在物の配向の影響評価口頭発表(一般)
- 第15回SPring-8産業利用報告会, 2018年09月, 日本語, 高輝度光科学財団, 兵庫県神戸市, 国内会議放射光X線ラミノグラフィによる転動疲労損傷発達挙動に及ぼす介在物形態の影響評価口頭発表(一般)
- 第15回SPring-8産業利用報告会, 2018年09月, 日本語, 高輝度光科学財団, 兵庫県神戸市, 国内会議調和組織材の引張過程におけるミスオリエンテーション変化の観察口頭発表(一般)
- 土木学会第73回年次学術講演会, 2018年08月, 日本語, 土木学会, 札幌市・北海道大学, 国内会議熱弾性応力計測による鋼構造部材の疲労き裂進展性評価口頭発表(一般)
- 土木学会第73回年次学術講演会, 2018年08月, 日本語, 土木学会, 札幌市・北海道大学, 国内会議赤外線カメラを用いた塗膜劣化評価による実橋調査口頭発表(一般)
- 土木学会第73回年次学術講演会, 2018年08月, 日本語, 土木学会, 札幌市・北海道大学, 国内会議近赤外線分光情報を用いた塗膜劣化評価法の提案口頭発表(一般)
- 土木学会第73回年次学術講演会, 2018年08月, 日本語, 土木学会, 札幌市・北海道大学, 国内会議近赤外線カメラを用いた重防食塗装最表層の損耗度定量評価口頭発表(一般)
- 第52回X線材料強度に関するシンポジウム, 2018年07月, 日本語, 日本材料学会, 静岡県静岡市, 国内会議高輝度放射光を用いたDCT-mCTインライン計測によるSUS304L調和組織材の引張損傷評価口頭発表(一般)
- The Sixth Japan-US NDT Symposium Emerging NDE Capabilities for a Safer World, 2018年07月, 英語, JSNDI and ASNT, Hawaii Convention Center, Oahu, Hawaii, USA, 国際会議Fatigue crack evaluation for steel bridge maintenance by infrared thermography口頭発表(一般)
- 日本ばね学会春季講演会, 2018年06月, 日本語, 日本ばね学会, 東京都千代田区, 国内会議放射光X線イメージング技術を活用した転動疲労内部き裂観察口頭発表(一般)
- 2018 SEM Annual Conference & Exposition, 2018年06月, 英語, SEM, Hyatt Regency Greenville, Greenville, South Carolina, USA, 国際会議Fatigue Limit Estimation for Single Bead-on-plate weld Based on Dissipated Energy Measurement口頭発表(一般)
- ICEM 2018, 2018年06月, 英語, Brussels, Belgium, 国際会議Fatigue Damage Evaluation by Diffraction Contrast Tomography Using Ultra-Bright Synchrotron Radiation口頭発表(基調)
- 2018 SEM Annual Conference & Exposition, 2018年06月, 英語, SEM, Hyatt Regency Greenville, Greenville, South Carolina, USA, 国際会議Evaluation of Fatigue Damage in Short Carbon Fiber Reinforced Plastics Based on Thermoelastic Stress and Phase Analysis口頭発表(一般)
- 日本材料学会第67期学術講演会, 2018年05月, 日本語, 日本材料学会, 高知市・高知工科大学, 国内会議熱弾性応力計測に基づく鋼構造溶接部の疲労き裂進展性評価口頭発表(一般)
- 日本材料学会第67期学術講演会, 2018年05月, 日本語, 日本材料学会, 高知市・高知工科大学, 国内会議アクティブ赤外線サーモグラフィ法による自動車構造材料の非破壊評価口頭発表(一般)
- Fatigue 2018, 2018年05月, 英語, Poitiers, France, 国際会議Observation of Flaking Process in Rolling Contact Fatigue by Laminography Using Ultra-bright Synchrotron Radiation口頭発表(一般)
- SPIE Defense + Commercial and Sensing 2018, Thermosense: Thermal Infrared Applications XL, 2018年04月, 英語, SPIE, Gaylord Palms Resort & Convention Center, Orlando, Florida, USA, 国際会議Application of infrared camera for steel bridge maintenance口頭発表(一般)
- 2017年度関西学生会学生員卒業研究発表講演会, 2018年03月, 日本語, 日本機械学会, 摂南大学,寝屋川市, 国内会議放射光DCTインライン計測によるSUS304L調和組織材のミスオリエンテーション変化の観察口頭発表(一般)
- 第334回疲労部門委員会, 2018年03月, 日本語, 日本材料学会, シーガイアコンベンションセンター,宮崎市, 国内会議高強度鋼の転動疲労損傷に及ぼす人口欠陥と硫化物系介在物の影響の高輝度放射光ラミノグラフィによる観察口頭発表(一般)
- 2017年度関西学生会学生員卒業研究発表講演会, 2018年03月, 日本語, 日本機械学会, 摂南大学,寝屋川市, 国内会議高輝度放射光ラミノグラフィによる非金属介在物を起点とした転動疲労き裂の発生および進展過程の観察口頭発表(一般)
- M&M2017材料力学カンファレンス, 2017年10月, 日本語, 日本機械学会, 北海道大学,札幌市, 国内会議放射光 DCT インライン計測による金属材料の疲労過程中のミスオリエンテーション変化の観察口頭発表(一般)
- 日本機械学会 M&M2017材料力学カンファレンス, 2017年10月, 日本語, 日本機械学会, 札幌市・北海道大学, 国内会議散逸エネルギ計測に及ぼす塗膜の影響口頭発表(一般)
- M&M2017材料力学カンファレンス, 2017年10月, 日本語, 日本機械学会, 北海道大学,札幌市, 国内会議高強度鋼の転動疲労損傷に及ぼす非金属介在物の影響の高輝度放射光ラミノグラフィによる観察口頭発表(一般)
- 土木学会第72回年次学術講演会, 2017年09月, 日本語, 土木学会, 福岡市・九州大学, 国内会議熱弾性応力分布計測結果の破壊力学評価による鋼構造部材の疲労き裂進展性評価口頭発表(一般)
- 土木学会第72回年次学術講演会, 2017年09月, 日本語, 土木学会, 福岡市・九州大学, 国内会議熱弾性応力分布計測結果の破壊力学評価による鋼橋の疲労き裂補修効果の検証口頭発表(一般)
- 2nd International Conference on Structural Integrity, 2017年09月, 英語, ICSI, Funchal, Madeira, Portugal, 国際会議TSA based evaluation of fatigue crack propagation in steel bridge members口頭発表(一般)
- 3rd International Symposium on Fatigue Design and Material Defects (FDMD) 2017, 2017年09月, 英語, Itallian Fracture Group, Lecco, Italy, 国際会議Rolling Contact Fatigue Damage from Artificial Defects and Sulphide Inclusions in High Strength Steel口頭発表(一般)
- AITA2017, The 14th International Workshop on Advanced Infrared Technology and Applications, 2017年09月, 英語, AITA, Quebec-city, Canada, 国際会議Effect of mean stress on phase difference of dissipated energy口頭発表(一般)
- AITA2017, The 14th International Workshop on Advanced Infrared Technology and Applications, 2017年09月, 英語, AITA, Quebec-city, Canada, 国際会議Detection of fatigue damage in short carbon fiber reinforced plastics using thermoelasticity口頭発表(一般)
- European Congress and Exhibition on Advanced Materials and Processes (EUROMAT) 2017, 2017年09月, 英語, Thessaloniki Concert Hall, Thessaloniki, Greece, 国際会議Change of misorientation of individual crystallographic planes in fatigue of alloys by diffraction contrast tomography using ultrabright synchrotron radiation口頭発表(一般)
- 14th International Conference on Fracture (ICF14), 2017年06月, 英語, Rodos Palace Hotel, Rhodes, Greece, 国際会議Crack Initiation and Propagation Behaviors under Rolling Contact Fatigue Observed by Laminography Using Synchrotron Radiation X-ray口頭発表(一般)
- 日本材料学会第66期学術講演会, 2017年05月, 日本語, 日本材料学会, 名古屋市・名城大学, 国内会議赤外線サーモグラフィを用いた黄銅に対する散逸エネルギ計測口頭発表(一般)
- 日本材料学会第66期学術講演会, 2017年05月, 日本語, 日本材料学会, 名古屋市・名城大学, 国内会議散逸エネルギ測定に基づく疲労強度推定法のアルミニウム合金A6061-T6 への適用口頭発表(一般)
- 日本材料学会第66期学術講演会, 2017年05月, 日本語, 日本材料学会, 名古屋市・名城大学, 国内会議散逸エネルギ計測に基づくビードオンプレート溶接部材に対する疲労限度推定口頭発表(一般)
- 第66期学術講演会, 2017年05月, 日本語, 日本材料学会, 名城大学,名古屋市, 国内会議高輝度放射光ラミノグラフィを用いた軸受鋼の転動疲労き裂進展挙動に及ぼすMnS介在物配向の影響評価口頭発表(一般)
- SPIE Defense + Commercial Sensing 2017, Thermosense: Thermal Infrared Applications XXXIX, 2017年04月, 英語, SPIE, Anaheim Convention Center, Anaheim, California, USA, 国際会議Fatigue limit estimation of titanium alloy Ti-6Al-4V with infrared thermographyポスター発表
- SPIE Defense + Commercial Sensing 2017, Thermosense: Thermal Infrared Applications XXXIX, 2017年04月, 英語, SPIE, Anaheim Convention Center, Anaheim, California, USA, 国際会議Fatigue damage evaluation of short fiber CFRP based on phase information of thermoelastic temperature change口頭発表(一般)
- 平成28年度関西学生会学生員卒業研究発表講演会, 2017年03月, 日本語, 日本機械学会関西支部, 大阪大学; 吹田市, 国内会議放射光回折コントラストトモグラフィを用いたマグネシウム合金 AZ31 における組織観察口頭発表(一般)
- 日本機械学会関西支部平成28年度卒業研究発表講演会, 2017年03月, 日本語, 日本機械学会関西支部, 大阪大学, 国内会議熱弾性応力可視化計測による鋼橋梁の疲労き裂補修効果の検証口頭発表(一般)
- 日本機械学会関西支部平成29年度卒業研究発表講演会, 2017年03月, 日本語, 日本機械学会関西支部, 大阪大学, 国内会議赤外線サーモグラフィを用いた銅合金に対する散逸エネルギ計測口頭発表(一般)
- 日本機械学会関西支部第91期定時総会講演会, 2017年03月, 日本語, 日本機械学会関西支部, 大阪大学, 国内会議赤外線サーモグラフィを用いた高倍率温度計測の取り組み口頭発表(一般)
- 平成28年度関西学生会学生員卒業研究発表講演会, 2017年03月, 日本語, 日本機械学会関西支部, 大阪大学; 吹田市, 国内会議軸受鋼の転動疲労機構に及ぼす非金属介在物の影響の高輝度放射光ラミノグラフィによる観察口頭発表(一般)
- 日本材料学会東海支部 第11回学術講演会, 2017年03月, 日本語, 日本材料学会東海支部, 名古屋大学, 国内会議散逸エネルギ測定に基づく疲労損傷評価に関する研究≪SUS316L鋼の熱処理条件の変化に対する疲労限度推定法の適用性≫口頭発表(一般)
- 日本機械学会関西支部平成29年度卒業研究発表講演会, 2017年03月, 日本語, 日本機械学会関西支部, 大阪大学, 国内会議ビードオンプレート溶接部における散逸エネルギ計測口頭発表(一般)
- 日本機械学会関西支部平成29年度卒業研究発表講演会, 2017年03月, 日本語, 日本機械学会関西支部, 大阪大学, 国内会議THz-TDSを用いた石油タンク底部鋼板の健全性評価口頭発表(一般)
- 日本機械学会関西支部平成29年度卒業研究発表講演会, 2017年03月, 日本語, 日本機械学会関西支部, 大阪大学, 国内会議THz-TDSを用いた石油タンク底部コーティングの劣化評価における滞留水分の影響評価口頭発表(一般)
- XXIV Italian Group of Fracture Conference, 2017年03月, 英語, Urbino, 国際会議Change of misorientation of individual grains in fatigue of polycrystalline alloys by diffraction contrast tomography using ultrabright synchrotron radiation口頭発表(一般)
- 日本機械学会関西支部平成29年度卒業研究発表講演会, 2017年03月, 日本語, 日本機械学会関西支部, 大阪大学, 国内会議5~8μm中間波長帯赤外線サーモグラフィによる建物診断時の反射低減効果口頭発表(一般)
- 第 53 回 X 線材料強度に関する討論会, 2016年12月, 日本語, 日本材料学会 X線強度部門委員会, 名古屋, 国内会議放射光ラミノグラフィを用いた転動疲労におけるき裂進展挙動のその場観察口頭発表(一般)
- 日本材料学会関西支部 第11回若手シンポジウム, 2016年12月, 日本語, 日本材料学会関西支部, 大津市, 国内会議散逸エネルギ測定に基づく損傷評価技術の開発 -疲労損傷評価の高精度化に向けた取り組み-ポスター発表
- M&M2016材料力学カンファレンス, 2016年10月, 日本語, 日本機械学会, 神戸大学; 神戸市, 国内会議放射光インライン計測によるステンレス鋼の疲労損傷評価口頭発表(一般)
- 日本機械学会 M&M2016材料力学カンファレンス,, 2016年10月, 日本語, 日本機械学会, 神戸大学, 国内会議熱弾性応力測定法による鋼構造溶接部の疲労き裂補修効果の検証ポスター発表
- 日本機械学会 M&M2016材料力学カンファレンス,, 2016年10月, 日本語, 日本機械学会, 神戸大学, 国内会議熱弾性応力測定に基づく合成床版の疲労損傷評価ポスター発表
- 日本機械学会 M&M2016材料力学カンファレンス,, 2016年10月, 日本語, 日本機械学会, 神戸大学, 国内会議短繊維CFRPにおける熱弾性温度変動の位相情報を用いた損傷評価ポスター発表
- 日本機械学会 M&M2016材料力学カンファレンス,, 2016年10月, 日本語, 日本機械学会, 神戸大学, 国内会議走査加熱を用いたアクティブ赤外線サーモグラフィ法による非破壊検査ポスター発表
- 日本機械学会 M&M2016材料力学カンファレンス,, 2016年10月, 日本語, 日本機械学会, 神戸大学, 国内会議赤外線サーモグラフィを用いた散逸エネルギの顕微計測口頭発表(一般)
- 日本材料学会関東支部 学生研究交流会, 2016年10月, 日本語, 日本材料学会関東支部, 東京都・早稲田大学, 国内会議散逸エネルギ測定に基づく材料の損傷評価「疲労限度と疲労破壊箇所の迅速推定」口頭発表(一般)
- 日本機械学会 M&M2016材料力学カンファレンス,, 2016年10月, 日本語, 日本機械学会, 神戸大学, 国内会議散逸エネルギ測定に基づくガセット溶接継手に対するき裂発生位置予測ポスター発表
- 日本機械学会 M&M2016材料力学カンファレンス,, 2016年10月, 日本語, 日本機械学会, 神戸大学, 国内会議散逸エネルギ計測に基づく疲労限度推定法の軽量化合金への適用性口頭発表(一般)
- M&M2016材料力学カンファレンス, 2016年10月, 日本語, 日本機械学会, 神戸大学; 神戸市, 国内会議高輝度放射光ラミノグラフィを用いた転動疲労き裂発生および進展挙動に及ぼす介在物配向の影響口頭発表(一般)
- 日本機械学会 M&M2016材料力学カンファレンス,, 2016年10月, 日本語, 日本機械学会, 神戸大学, 国内会議パルス加熱赤外線サーモグラフィ法による溶射皮膜材料の非破壊評価ポスター発表
- 日本機械学会 M&M2016材料力学カンファレンス,, 2016年10月, 日本語, 日本機械学会, 神戸大学, 国内会議テラヘルツ電磁波による3Dイメージングに関する基礎検討ポスター発表
- M&M2016材料力学カンファレンス, 2016年10月, 日本語, 日本機械学会, 神戸大学; 神戸市, 国内会議Ti-6Al-4Vの超高サイクル疲労における内部破壊初期過程の放射光µCTイメージング口頭発表(一般)
- MS&T 16, 2016年10月, 英語, Salt Lake City, 国際会議Inclusion Orientation Effect on Rolling Contact Fatigue Crack Paths Observed by Laminography Using Synchrotron Radiation X-Ray口頭発表(一般)
- 土木学会第71回年次学術講演会, 2016年09月, 日本語, 土木学会, 仙台市・東北大学, 国内会議熱弾性応力測定による鋼構造の疲労き裂補修対策実施効果の検証口頭発表(一般)
- 土木学会第71回年次学術講演会, 2016年09月, 日本語, 土木学会, 仙台市・東北大学, 国内会議突起リブを採用した鋼コンクート合成床版に対する熱弾性応力測 定に基づく底鋼板下面の応力評価口頭発表(一般)
- 土木学会第71回年次学術講演会, 2016年09月, 日本語, 土木学会, 仙台市・東北大学, 国内会議鋼床版支点部補剛材に生じた亀裂の補修口頭発表(一般)
- 日本非破壊検査協会赤外線サーモグラフィ部門ミニシンポジウム, 2016年09月, 日本語, 日本材料学会破壊力学部門委員会非破壊検査小委員会, 神戸大学, 国内会議Nondestructive evaluation of fatigue damage in CFRP composites based on thermoelastic stress analysis口頭発表(一般)
- 21st European Conference on Fracture, 2016年06月, 日本語, Catania, 国際会議Effects of inclusion size and orientation on rolling contact fatigue crack initiation observed by laminography using ultra-bright synchrotron radiation口頭発表(一般)
- 日本材料学会第65期学術講演会, 2016年05月, 日本語, 日本材料学会, 富山大学, 国内会議熱弾性温度変動の位相解析に基づく短繊維CFRPにおける繊維配向性の評価口頭発表(一般)
- 日本材料学会第65期学術講演会, 2016年05月, 日本語, 日本材料学会, 富山大学, 国内会議赤外線サーモグラフィによる顕微拡大散逸エネルギ測定によるSUS316L鋼の疲労損傷評価口頭発表(一般)
- 第65期学術講演会, 2016年05月, 日本語, 日本材料学会, 富山大学; 富山市, 国内会議ステンレス鋼における高サイクル疲労中のミスオリエンテーション変化の放射光DCTによる観察口頭発表(一般)
- 第65期学術講演会, 2016年05月, 日本語, 日本材料学会, 富山大学; 富山市, 国内会議MnS介在物を起点とした転動疲労き裂発生および成長の高輝度放射光ラミノグラフィによる4D観察口頭発表(一般)
- THERMEC‘2016, 2016年05月, 英語, Graz, 国際会議Misorientation measurement of individual grains in fatigue of polycrystalline alloys by diffraction contrast tomography using ultrabright synchrotron radiation[招待有り]口頭発表(招待・特別)
- 日本機械学会関西支部第91期定時総会講演会, 2016年03月, 日本語, 日本機械学会関西支部, 大阪電気通信大学, 国内会議熱弾性応力計測に基づく合成床版スタッドの疲労き裂発生検出口頭発表(一般)
- 日本機械学会関西支部第91期定時総会講演会, 2016年03月, 日本語, 日本機械学会関西支部, 大阪電気通信大学, 国内会議赤外線サーモグラフィを用いた微小試験片に対する熱弾性応力測定口頭発表(一般)
- 日本機械学会関西支部第91期定時総会講演会, 2016年03月, 日本語, 日本機械学会関西支部, 大阪電気通信大学, 国内会議赤外線サーモグラフィを用いた熱弾性応力測定-微小部品の応力測定を目指して-口頭発表(一般)
- 日本機械学会関西支部第91期定時総会講演会, 2016年03月, 日本語, 日本機械学会関西支部, 大阪電気通信大学, 国内会議散逸エネルギ計測に基づいた疲労強度およびき裂発生位置の迅速推定口頭発表(一般)
- 日本機械学会関西支部第91期定時総会講演会, 2016年03月, 日本語, 日本機械学会関西支部, 大阪電気通信大学, 国内会議高分子系複合材料の赤外線計測に基づく疲労損傷評価口頭発表(一般)
- 日本機械学会関西支部第91期定時総会講演会, 2016年03月, 日本語, 日本機械学会関西支部, 大阪電気通信大学, 国内会議高分子系複合材料における散逸エネルギ計測口頭発表(一般)
- 日本機械学会関西学生会平成27年度学生員卒業研究発表講演会, 2016年03月, 日本語, 寝屋川市, 国内会議高輝度放射光ラミノグラフィによるMnS介在物を起点とした転動疲労き裂進展過程の観察口頭発表(一般)
- 日本機械学会関西学生会平成27年度学生員卒業研究発表講演会, 2016年03月, 日本語, 寝屋川市, 国内会議高輝度放射光によるオーステナイト系ステンレス鋼の疲労過程におけるミスオリエンテーション変化の観察口頭発表(一般)
- 日本機械学会関西支部第91期定時総会講演会, 2016年03月, 日本語, 日本機械学会関西支部, 大阪電気通信大学, 国内会議逆問題解析を用いた防食塗装膜下の熱弾性応力測定口頭発表(一般)
- 日本機械学会関西支部第91期定時総会講演会, 2016年03月, 日本語, 日本機械学会関西支部, 大阪電気通信大学, 国内会議オーステナイト系ステンレス鋼における応力および散逸エネルギの顕微計測口頭発表(一般)
- 日本機械学会関西支部第91期定時総会講演会, 2016年03月, 日本語, 日本機械学会関西支部, 大阪電気通信大学, 国内会議THz-TDSを用いた塗装膜下鋼板の健全性評価口頭発表(一般)
- 日本機械学会M&M2015材料力学カンファレンス, 2015年11月, 日本語, 横浜市, 国内会議高輝度放射光ラミノグラフィを用いた転動疲労き裂の発生および進展過程の観察口頭発表(一般)
- 日本機械学会M&M2015材料力学カンファレンス, 2015年11月, 日本語, 横浜市, 国内会議高輝度放射光によるステンレス鋼の疲労におけるミスオリエンテーション評価口頭発表(一般)
- 日本機械学会M&M2015 材料力学カンファレンス, 2015年11月, 日本語, 日本機械学会材料力学部門, 慶應義塾大学, 国内会議位相情報を用いた散逸エネルギ測定および疲労限度推定の高精度化口頭発表(一般)
- 日本機械学会M&M2015 材料力学カンファレンス, 2015年11月, 日本語, 日本機械学会材料力学部門, 慶應義塾大学, 国内会議マグネシウム合金AZ31Bにおける散逸エネルギ測定口頭発表(一般)
- 日本機械学会M&M2015 材料力学カンファレンス, 2015年11月, 日本語, 日本機械学会材料力学部門, 慶應義塾大学, 国内会議テラヘルツ電磁波による欠陥イメージングに関する基礎的研究口頭発表(一般)
- 第17回破壊力学シンポジウム, 2015年10月, 日本語, 日本材料学会, 京都市, 国内会議顕微拡大視野赤外線サーモグラフィを用いた熱弾性応力測定の基礎的検討口頭発表(一般)
- International Conference on Advanced Technology in Experimental Mechanics 2015, 2015年10月, 英語, Toyohashi,JAPAN, 国際会議Evaluation of High Cycle Fatigue Damagefor Austenitic Stainless Steel by Diffraction Contrast TomographyUsing Ultra-bright Synchrotron Radiation口頭発表(一般)
- International Conference on Advanced Technology in Experimental Mechanics 2015 (ATEM’15), 2015年10月, 英語, 日本機械学会材料力学部門, 豊橋市, 国際会議4D Observations of Pit Growth and Crack Initiation under Corrosion Fatigue of High-strength Aluminum Alloy by Micro CT Imaging Using Ultra-bright Synchrotron Radiation口頭発表(一般)
- International Conference on Advanced Technology in Experimental Mechanics 2015, 2015年10月, 英語, Toyohashi,JAPAN, 国際会議4D Observation of Crack Propagation Behavior under Rolling Contact Fatigue by Synchrotron Radiation Laminography口頭発表(一般)
- 第12回SPring-8産業利用報告会, 2015年09月, 日本語, 川崎市, 国内会議放射光X線ラミノグラフィによる鉄鋼材料の転動疲労損傷観察ポスター発表
- 第12回SPring-8産業利用報告会, 2015年09月, 日本語, 川崎市, 国内会議回折コントラストイメージングによる金属材料の疲労損傷評価ポスター発表
- The 5th International Conference on Crack Paths, 2015年09月, 英語, Ferrara,ITALY, 国際会議In situ observation of rolling contact fatigue cracks by laminography using ultrabright synchrotron radiation口頭発表(一般)
- ATEM'15: International Conference on Advanced Technology in Experimental Mechanics 2015, 2015年09月, 英語, 日本機械学会, Toyohashi, Japan, 国際会議Fatigue Limit Estimation Based on Dissipated Energy for Pre-Strained Materials口頭発表(一般)
- The 5th International Conference on Crack Paths, 2015年09月, 英語, Ferrara,ITALY, 国際会議Effect of defect length on rolling contact fatigue crack propagation in high strength steel口頭発表(一般)
- 赤外線サーモグラフィ部門ミニシンポジウム, 2015年08月, 日本語, 日本非破壊検査協会, 三鷹市, 国内会議パルスサーモグラフィおよびテラヘルツ計測によるコーティング下の腐食検出口頭発表(一般)
- 日本材料学会 第321回疲労部門委員会, 2015年07月, 日本語, 日本材料学会 疲労部門委員会, 姫路市, 国内会議高輝度放射光の回折コントラストトモグラフィーによる疲労すべりの3D観察口頭発表(招待・特別)
- 日本材料学会 第64期学術講演会, 2015年05月, 日本語, 日本材料学会, 米沢市, 国内会議深さ方向に異なる長さの人工欠陥を導入した高強度鋼の転動疲労特性口頭発表(一般)
- 第64期日本材料学会学術講演会, 2015年05月, 日本語, 日本材料学会, 米沢市, 国内会議散逸エネルギ測定によるSUS316L鋼予ひずみ材の疲労強度評価口頭発表(一般)
- 日本材料学会 第64期学術講演会, 2015年05月, 日本語, 日本材料学会, 米沢市, 国内会議高輝度放射光を用いた回折コントラストトモグラフィによるSUS316L鋼の高サイクル疲労損傷の評価口頭発表(一般)
- 第64期日本材料学会学術講演会, 2015年05月, 日本語, 日本材料学会, 米沢市, 国内会議位相ロックイン法を用いた散逸エネルギ測定の改善口頭発表(一般)
- 12th International Conference on the Materials Behavior of Materials, 2015年05月, 英語, Karlsruhe,GERMANY, 国際会議Fatigue damage evaluation of polycrystaline alloy by diffraction contrast tomography using ultra-bright synchrotron radiation口頭発表(一般)
- ICM12, 12th International Conference on the Mechanical Behavior of Materials, 2015年05月, 英語, Karlsruhe, Germany, 国際会議Accuracy improvement of fatigue damage evaluation based on phase analysis of dissipated energy口頭発表(一般)
- 日本機械学会関西支部 第90 期定時総会講演会, 2015年03月, 日本語, 日本機械学会関西支部, 京都大学 桂キャンパス;京都市, 国内会議放射光ラミノグラフィを用いた転動疲労き裂進展の4D 解析口頭発表(一般)
- 日本機械学会関西支部第90期定時総会講演会(修士研究発表セッション), 2015年03月, 日本語, 日本機械学会関西支部, 国内会議熱弾性応力測定法に基づくき裂進展抑制効果の検証口頭発表(一般)
- 日本機械学会関西学生会平成26年度学生員卒業研究発表講演会, 2015年03月, 日本語, 日本機械学会関西支部, 国内会議熱弾性応力計測に基づく鋼構造のき裂進展評価口頭発表(一般)
- 日本機械学会関西支部第90期定時総会講演会(修士研究発表セッション), 2015年03月, 日本語, 日本機械学会関西支部, 国内会議熱弾性応力計測に基づく橋梁の構造健全性評価口頭発表(一般)
- 日本機械学会関西支部第90期定時総会講演会, 2015年03月, 日本語, 日本機械学会関西支部, 京都市, 国内会議赤外線温度計測に基づく疲労き裂の非破壊評価口頭発表(一般)
- 日本機械学会関西学生会平成26年度学生員卒業研究発表講演会, 2015年03月, 日本語, 日本機械学会関西支部, 国内会議散逸エネルギ測定に基づくSUS316L鋼予ひずみ材の疲労限度評価口頭発表(一般)
- 日本機械学会関西支部第90期定時総会講演会(修士研究発表セッション), 2015年03月, 日本語, 日本機械学会関西支部, 国内会議散逸エネルギ計測に基づくキャビテーション材の疲労限度予測口頭発表(一般)
- 日本機械学会関西支部第90期定時総会講演会, 2015年03月, 日本語, 日本機械学会関西支部, 京都市, 国内会議散逸エネルギに基づく疲労限度推定における推定メカニズムに関する検討口頭発表(一般)
- 日本機械学会関西学生会平成26 年度学生員卒業研究発表講演会, 2015年03月, 日本語, 日本機械学会関西支部, 京都大学 桂キャンパス;京都市, 国内会議高輝度放射光を用いた回折コントラストトモグラフィーによる高サイクル疲労損傷評価口頭発表(一般)
- 日本機械学会関西学生会平成26 年度学生員卒業研究発表講演会, 2015年03月, 日本語, 日本機械学会関西支部, 京都大学 桂キャンパス;京都市, 国内会議高輝度放射光ラミノグラフィーを用いた転動疲労き裂進展観察口頭発表(一般)
- 日本機械学会関西支部 第90 期定時総会講演会, 2015年03月, 日本語, 日本機械学会関西支部, 京都大学 桂キャンパス;京都市, 国内会議高輝度放射光の回折コントラストイメージングによる疲労過程中の転位構造変化の観察口頭発表(一般)
- 日本機械学会関西学生会平成26年度学生員卒業研究発表講演会, 2015年03月, 日本語, 日本機械学会関西支部, 国内会議マグネシウム合金AZ31Bにおける散逸エネルギ測定に及ぼす高調波応力成分の影響口頭発表(一般)
- 日本機械学会関西支部第90期定時総会講演会(修士研究発表セッション), 2015年03月, 日本語, 日本機械学会関西支部, 国内会議マグネシウム合金AZ31B における散逸エネルギを用いた疲労限度推定口頭発表(一般)
- 日本機械学会関西支部第90期定時総会講演会(修士研究発表セッション), 2015年03月, 日本語, 日本機械学会関西支部, 国内会議パルス加熱赤外線サーモグラフィ法による防食塗装膜の潜在的劣化評価口頭発表(一般)
- 日本機械学会関西学生会平成26年度学生員卒業研究発表講演会, 2015年03月, 日本語, 日本機械学会関西支部, 国内会議アクティブ赤外線サーモグラフィ法によるコーキング厚さ同定口頭発表(一般)
- 日本機械学会関西学生会平成26年度学生員卒業研究発表講演会, 2015年03月, 日本語, 日本機械学会関西支部, 国内会議THz-TDS を用いた保温材下の腐食検出に関する基礎検討口頭発表(一般)
- 第10回SPring-8金属材料評価研究会, 2015年02月, 日本語, 高輝度光科学研究センター, 研究社英語センタービル;東京都, 国内会議放射光ラミノグラフィによる介在物起点の転動疲労き裂進展挙動の観察口頭発表(招待・特別)
- 日本材料学会第51回X線材料強度に関する討論会, 2014年12月, 日本語, 日本材料学会, 名古屋市, 国内会議赤外線温度計測に基づく疲労き裂の非破壊評価法[招待有り]口頭発表(招待・特別)
- The APCFS/SIF-2014 Congress uniting: Asian-Pacific Conference on Fracture and Strength (APCFS-2014), International Conference on Structural Integrity and Failure (SIF-2014), 2014年12月, 英語, Sydney, Australia, 国際会議A new approach for evaluating stress intensity factor based on thermoelastic stress analysis口頭発表(一般)
- Proceedings of the 3rd Japan-China Joint Symposium on Fatigue of Engineering Materials and Structures, 2014年11月, 英語, 日本材料学会, 高山市民会館;高山市, 国際会議Evaluation of Fatigue Damage in Polycrystalline Alloys by Diffraction Contrast Tomography using Ultra-bright Synchrotron Radiation口頭発表(招待・特別)
- 日本高圧力技術協会平成26年度秋季講演会, 2014年10月, 日本語, 日本高圧力技術協会, 松山市, 国内会議散逸エネルギ計測に基づく疲労限度評価法に関する実験的検討口頭発表(一般)
- International Conference on Fatigue Damage of Structural Materials X, 2014年09月, 英語, The Resort and Conference Center at Hyannis; MA; USA, 国際会議4D evaluation of grain shape and fatigue damage of individual grain in polycrystalline alloys by diffraction contrast tomography using ultra-bright synchrotron radiation口頭発表(一般)
- 日本機械学会材料力学カンファレンス(M&M2014), 2014年07月, 日本語, 日本機械学会, 福島大学;福島市, 国内会議高輝度放射光ラミノグラフィを用いた高強度鋼中の転動疲労き裂の観察口頭発表(一般)
- 20th European Conference on Fracture (ECF20), 2014年07月, 英語, Norwegian University of Science and Technology; Trondheim; Norway, 国際会議Observation of rolling contact fatigue cracks by laminography using ultra-bright synchrotron radiation口頭発表(一般)
- 日本材料学会第63期学術講演会, 2014年05月, 日本語, 日本材料学会, 福岡大学;福岡市, 国内会議放射光回折コントラストトモグラフィによる低サイクル疲労の損傷評価口頭発表(一般)
- 日本機械学会関西学生会平成25年度学生員卒業研究発表講演会, 2014年03月, 日本語, 日本機械学会, 大阪府立大学,堺, 国内会議放射光回折コントラストトモグラフィによる低サイクル疲労の損傷評価口頭発表(一般)
- 日本機械学会関西学生会平成25年度学生員卒業研究発表講演会, 2014年03月, 日本語, 日本機械学会, 大阪府立大学,堺, 国内会議放射光ラミノグラフィによる高強度鋼における転動疲労き裂の観察口頭発表(一般)
- 日本機械学会関西支部第89期定時総会講演会, 2014年03月, 日本語, 日本機械学会関西支部, 大阪府立大学, 国内会議熱弾性応力分布測定に基づく混合モード応力拡大係数評価口頭発表(一般)
- 日本機械学会関西支部平成25 年度学生員卒業研究発表講演会, 2014年03月, 日本語, 日本機械学会関西支部, 大阪府立大学, 国内会議展伸マグネシウム合金AZ31 の散逸エネルギ計測による疲労限度推定口頭発表(一般)
- 日本機械学会関西支部第89期定時総会講演会, 2014年03月, 日本語, 日本機械学会関西支部, 大阪府立大学, 国内会議展伸マグネシウム合金AZ31B の散逸エネルギ計測による疲労限度評価口頭発表(一般)
- 日本機械学会関西支部 第89期定時総会講演会, 2014年03月, 日本語, 日本機械学会, 大阪府立大学,堺, 国内会議高感度磁気センサを用いた渦電流探傷システムによる深部欠陥の検出に関する研究口頭発表(一般)
- 日本機械学会関西支部 第89期定時総会講演会, 2014年03月, 日本語, 日本機械学会, 大阪府立大学,堺, 国内会議ピエゾセンサシートおよび逆問題解析を用いた接触センシングの開発口頭発表(一般)
- 11th International Fatigue Congress (Fatigue 2014), 2014年03月, 英語, Melbourne, Australia, 国際会議Fatigue of ultra-fine grained α-brass口頭発表(一般)
- Fatigue 2014, 2014年03月, 英語, RMT university, Melbourne, Australia, 国際会議Experimental study of relationship between energy dissipation and fatigue damage from observation of slip band by atomic force microscope口頭発表(一般)
- 11th International Fatigue Congress (Fatigue 2014), 2014年03月, 英語, Melbourne, Australia, 国際会議Evaluation of Fatigue Damage by Diffraction Contrast Imaging using Ultra-bright Synchrotron Radiation口頭発表(一般)
- 第63期日本材料学会学術講演会, 2014年, 日本語, 日本材料学会, 国内会議展伸マグネシウム合金における散逸エネルギと疲労損傷の関係口頭発表(一般)
- M&M2014材料力学カンファレンス, 2014年, 日本語, 日本機械学会材料力学部門, 国内会議展伸 Mg 合金 AZ31B における散逸エネルギと変形機構との関係口頭発表(一般)
- M&M2014材料力学カンファレンス, 2014年, 日本語, 日本機械学会材料力学部門, 国内会議散逸エネルギの位相情報を用いた疲労損傷評価の改善口頭発表(一般)
- 第63期日本材料学会学術講演会, 2014年, 日本語, 日本材料学会, 国内会議散逸エネルギの位相情報を用いた疲労損傷評価口頭発表(一般)
- 第63期日本材料学会学術講演会, 2014年, 日本語, 日本材料学会, 国内会議混合モード下の赤外線応力測定に基づくき裂の応力拡大係数評価口頭発表(一般)
- 本機械学会 第27回計算力学講演会(CMD2014), 2014年, 日本語, 日本機械学会計算力学部門, 国内会議逆問題解析を援用したコーティング下の応力測定口頭発表(一般)
- M&M2014材料力学カンファレンス, 2014年, 日本語, 日本機械学会材料力学部門, 国内会議ガラス短繊維複合材料における散逸エネルギ計測口頭発表(一般)
- International Conference on Processing & Manufacturing of Advanced Materials (THERMEC'2013), 2013年12月, 英語, Las Vegas, USA, 国際会議Evaluation of Fatigue Damage by Diffraction Contrast Imaging using Ultra-bright Synchrotron Radiation[招待有り]口頭発表(招待・特別)
- 日本材料学会第16回破壊力学シンポジウム講演論文集, pp.321-316 (2013, 11.20-22, 阿蘇ファームランド)., 2013年11月, 日本語, 日本材料学会, 阿蘇ファームランド,熊本, 国内会議放射光μCTイメージングによる腐食疲労におけるピットの成長及びき裂発生過程の4D解析口頭発表(一般)
- 本材料学会 信頼性・破壊力学合同シンポジウム(第16回破壊力学シンポジウム), 2013年11月, 日本語, 日本材料学会, 阿蘇ファームランド, 国内会議散逸エネルギ評価に基づくSUS316L鋼表面改質材の疲労限度評価口頭発表(一般)
- 日本材料学会第16回破壊力学シンポジウム講演論文集, pp.312-316 (2013, 11.20-22, 阿蘇ファームランド)., 2013年11月, 日本語, 日本材料学会, 阿蘇ファームランド,熊本, 国内会議高輝度放射光を用いた回折コントラストイメージによるき裂発生過程の結晶組織観察口頭発表(一般)
- 日本機械学会材料力学カンファレンス(M&M2013), 2013年10月, 日本語, 日本機械学会, 岐阜大学,岐阜, 国内会議放射光μCT 及び小型転動疲労試験機を用いた転動疲労き裂進展過程の観察口頭発表(一般)
- 日本機械学会材料力学カンファレンス(M&M2013), 2013年10月, 日本語, 日本機械学会, 岐阜大学,岐阜, 国内会議放射光μCT イメージングを用いたTi-6Al-4V 内部に発生する微小疲労き裂の検出口頭発表(一般)
- 日本機械学会材料力学カンファレンス(M&M2013), 2013年10月, 日本語, 日本機械学会, 岐阜大学,岐阜, 国内会議散逸エネルギ計測に基づく展伸マグネシウム合金の疲労限度評価口頭発表(一般)
- 日本機械学会材料力学カンファレンス(M&M2013), 2013年10月, 日本語, 日本機械学会, 岐阜大学,岐阜, 国内会議高輝度放射光を用いた回折コントラストトモグラフィによる疲労損傷評価に関する検討口頭発表(一般)
- 日本機械学会材料力学カンファレンス(M&M2013), 2013年10月, 日本語, 日本機械学会, 岐阜大学,岐阜, 国内会議α黄銅超微細結晶粒材の疲労強度口頭発表(一般)
- 日本機械学会 M&M2013材料力学カンファレンス, 2013年10月, 日本語, 日本機械学会, 岐阜大学, 国内会議SUS316L鋼表面改質材の散逸エネルギ計測による疲労限度評価口頭発表(一般)
- International Conference on Advanced Infrared Technology and Applications2013, 2013年09月, 英語, Torino, Italy, 国際会議Experimental study of relationship between energy dissipation and fatigue damage initiation based on observation of slip band by atomic force microscope口頭発表(一般)
- 13th International Symposium on Nondestructive Characterization of Materials, 2013年05月, 英語, Center for Nondestructive Evaluation, Le Mans, France,, 国際会議Fatigue limit estimation based on dissipated energy measurement for steel specimen with multiple notches口頭発表(一般)
- 13th International Symposium on Nondestructive Characterization of Materials, 2013年05月, 英語, 国際会議Evaluation of Fatigue Damage by Diffraction Contrast TomographyUsing Synchrotron Radiation口頭発表(一般)
- 日本材料学会第62期学術講演会, 2013年05月, 日本語, 日本材料学会, 東京工業大学, 国内会議AFMによるすべり帯観察に基づく散逸エネルギの発生および疲労限度予測メカニズムに関する検討口頭発表(一般)
- 日本機械学会関西学生会平成 24 年度学生員卒業研究発表講演会, 2013年03月, 日本語, 日本機械学会, 大阪市, 国内会議放射光μCT 及び小型転動疲労試験機を用いた高強度鋼における転動疲労下のき裂進展過程の観察口頭発表(一般)
- 日本機械学会関西支部第88期定時総会講演会, 2013年03月, 日本語, 日本機械学会, 大阪市, 国内会議放射光μCTイメージモデルに基づいた有限要素解析によるねじり疲労き裂進展挙動の評価口頭発表(一般)
- 日本機械学会関西学生会平成 24 年度学生員卒業研究発表講演会, 2013年03月, 日本語, 日本機械学会, 大阪市, 国内会議散逸エネルギを用いた圧延マグネシウム合金における疲労損傷評価口頭発表(一般)
- 日本機械学会関西学生会平成 24 年度学生員卒業研究発表講演会, 2013年03月, 日本語, 日本機械学会, 大阪市, 国内会議高輝度放射光を用いた回折コントラストトモグラフィによる金属組織評価口頭発表(一般)
- 日本機械学会関西支部第88期定時総会講演会, 2013年03月, 日本語, 日本機械学会, 大阪市, 国内会議高輝度放射光による三次元結晶マッピング法を用いた多結晶金属組織観察口頭発表(一般)
- 日本機械学会関西支部第88期定時総会講演会, 2013年03月, 日本語, 日本機械学会, 大阪市, 国内会議黄銅超微細結晶粒材作製法の開発とその強度評価口頭発表(一般)
- 日本機械学会関西学生会平成 24 年度学生員卒業研究発表講演会, 2013年03月, 日本語, 日本機械学会, 大阪市, 国内会議黄銅の微細結晶粒化と強度評価口頭発表(一般)
- 日本機械学会関西学生会平成 24 年度学生員卒業研究発表講演会, 2013年03月, 日本語, 日本機械学会, 大阪市, 国内会議グリーンコンポジットへの適用を目的としたアブラヤシ繊維の強度評価口頭発表(一般)
- 日本機械学会関西支部第88期定時総会講演会, 2013年03月, 日本語, 日本機械学会, 大阪市, 国内会議オーステナイト系ステンレス鋼における疲労限度の簡易予測法口頭発表(一般)
- 第4回日本複合材料合同会議, 2013年03月, 英語, 日本材料学会, 東京都, 国内会議Influence of Alkali Treatment on the Mechanical Properties of Oil Palm Fibers口頭発表(一般)
- 第26回日本放射光学会年会 放射光科学合同シンポジウム, 2013年01月, 日本語, 名古屋大学, 国内会議回折コントラストトモグラフィーによる結晶組織観察と損傷評価への適用[招待有り]シンポジウム・ワークショップパネル(指名)
- 日本材料学会第31回疲労シンポジウム, 2012年11月, 日本語, 日本材料学会, 横浜市, 国内会議放射光μCT イメージングを用いた高強度鋼における転動疲労き裂進展挙動の観察口頭発表(一般)
- 第31回疲労シンポジウム, 2012年11月, 日本語, 公益社団法人 日本材料学会, 慶應義塾大学 日吉キャンパス, 国内会議放射光μCTイメージングを用いた高強度鋼における転動疲労き裂進展挙動の観察口頭発表(一般)
- The 5th International Symposium on Designing, Processing and Properties of Advanced Engineering Materials (ISAEM-201), 2012年11月, 英語, 豊橋市, 国際会議Observation of Crack Propagation under Rolling Contact Fatigue in High-Strength Steels by Micro CT Imaging口頭発表(一般)
- The 5th International Symposium on Designing, Processing and Properties of Advanced Engineering Materials (ISAEM-2012), 2012年11月, 英語, 豊橋市, 国際会議Evaluation of Plastic Strain by Three-Dimensional Grain Mapping Technique Using SPring-8口頭発表(一般)
- 日本機械学会M&M2011材料力学カンファレンス, 2012年09月, 日本語, 日本機械学会, 松山市, 国内会議散逸エネルギ計測に基づく複数切欠き試験片に対する疲労限度予測口頭発表(一般)
- The 4th International Conference on Crack Paths (CP 2012), 2012年09月, 英語, Gaeta, Italy, 国際会議Observation of Fatigue Crack Propagation Mode Transition under Cyclic Torsion Using Micro-CT Imaging with Ultra-Bright Synchrotron Radiation[招待有り]口頭発表(招待・特別)
- The 4th International Conference on Crack Paths (CP 2012), , 19 - 21 September, 2012, 2012年09月, 英語, Gaeta, Italy, 国際会議Evaluation of rolling contact fatigue crack path of high strength steel with artificial defect口頭発表(一般)
- 15th International Conference on Experimental Mechanics, 2012年07月, 英語, Porto, Portugal, 国際会議RELATIONSHIP BETWEEN DISSIPATED ENERGY AND FATIGUE LIMIT FOR AUSTENITIC STAINLESS STEEL口頭発表(一般)
- 15th International Conference on Experimental Mechanics, 2012年07月, 英語, Porto, Portugal, 国際会議Observation of Cracks in Carbon Steel under Contact Rolling Fatigue by Micro CT Imaging using Ultra-bright Synchrotron Radiation口頭発表(一般)
- 15th International Conference on Experimental Mechanics, 2012年07月, 英語, Porto, Portugal, 国際会議Development of Three-Dimensional Grain Mapping Technique in Spring-8 and Evaluation of Plastic Strain口頭発表(一般)
- 日本材料学会・第61期通常総会・学術講演会, 2012年05月, 日本語, 日本材料学会, 岡山市, 国内会議結晶3Dマッピング法による塑性ひずみ評価法の開発口頭発表(一般)
- 日本材料学会第61期学術講演会, 2012年05月, 日本語, 日本材料学会, 岡山市, 国内会議オーステナイト系ステンレス鋼の散逸エネルギ計測に基づく疲労限度予測に及ぼすマルテンサイト変態の影響口頭発表(一般)
- 日本機械学会関西支部第87期定時総会講演会, 2012年03月, 日本語, 日本機械学会関西支部, 吹田市, 国内会議放射光μCTを用いた高強度鋼における転動疲労下のき裂観察口頭発表(一般)
- 日本機械学会関西学生会平成23年度学生員卒業研究発表講演会, 2012年03月, 日本語, 日本機械学会関西支部, 吹田市, 国内会議高分子ピエゾセンサシートを利用した逆問題的計測手法の開発口頭発表(一般)
- 日本機械学会関西支部第87期定時総会講演会, 2012年03月, 日本語, 日本機械学会関西支部, 吹田市, 国内会議高輝度放射光の回折コントラストイメージを用いた三次元結晶マッピング法口頭発表(一般)
- 日本機械学会関西支部第87期定時総会講演会, 2012年03月, 日本語, 日本機械学会関西支部, 吹田市, 国内会議高感度MIセンサを用いた漏洩および渦電流式欠陥検出法の開発口頭発表(一般)
- 日本機械学会関西学生会平成23年度学生員卒業研究発表講演会, 2012年03月, 日本語, 日本機械学会関西支部, 吹田市, 国内会議高感度MIセンサを用いた漏洩および渦電流式欠陥検出口頭発表(一般)
- 日本機械学会関西学生会平成23年度卒業研究発表講演会, 2012年03月, 日本語, 日本機械学会, 吹田市, 国内会議オーステナイト系ステンレス鋼の散逸エネルギ計測による疲労限度評価口頭発表(一般)
- 日本機械学会関西学生会平成23年度学生員卒業研究発表講演会, 2012年03月, 日本語, 日本機械学会関西支部, 吹田市, 国内会議CTイメージングを用いた高強度鋼の転動疲労下のき裂観察口頭発表(一般)
- 日本材料学会第15回破壊力学シンポジウム, 2011年11月, 日本語, 日本材料学会, 石垣市, 国内会議SUS304鋼の散逸エネルギと疲労限度の関係口頭発表(一般)
- International Conference on Advanced Technology in Experimental Mechanics 2011, 2011年09月, 英語, JSME, Kobe, Japan, 国際会議Observation of Delamination Defects and Cracks in High-strength Steels under Rolling Contact Fatigue by SR Micro CT Imaging口頭発表(一般)
- International Conference on Advanced Technology in Experimental Mechanics 2011, 2011年09月, 英語, JSME, Kobe, Japan, 国際会議Evaluation of Torsional Fatigue Crack Propagation by Synchrotron Radiation Micro-CT Imaging口頭発表(一般)
- ATEM’11 International Conference on Advanced Technology in Experimental Mechanics 2011, 2011年09月, 英語, JSME, Kobe, 国際会議Dissipated energy evaluation during fatigue test for austenitic stainless steel with thermography口頭発表(一般)
- International Conference on Advanced Technology in Experimental Mechanics 2011, 2011年09月, 英語, JSME, Kobe, Japan, 国際会議Development of Three-dimensional Grain Mapping Technique Using SPring-8口頭発表(一般)
- 日本機械学会M&M2011材料力学カンファレンス, 2011年07月, 日本語, 日本機械学会, 北九州市, 国際会議放射光μCTを用いた高強度鋼の転動疲労下のき裂検出口頭発表(一般)
- M&M2011材料力学カンファレンス, 2011年07月, 日本語, 日本機械学会, 北九州市, 国内会議散逸エネルギ評価法によるSUS304 鋼の疲労限度推定の測定条件に関する検討口頭発表(一般)
- M&M2011材料力学カンファレンス, 2011年07月, 日本語, 日本機械学会, 北九州市, 国内会議SUS304 鋼の疲労試験での散逸エネルギ評価口頭発表(一般)
- 日本機械学会M&M2011材料力学カンファレンス, 2011年07月, 日本語, 日本機械学会, 北九州市, 国際会議SUS304鋼の応力誘起マルテンサイト変態挙動を利用した疲労損傷評価口頭発表(一般)
- 11th International Conference on Mechanical Behavior of Materials, 2011年06月, 英語, ICM, Lake Como, Italy, 国際会議Observation of Fatigue Crack Propagation Behavior under Torsional Loading by Using Synchrotron Radiation Micro-CT Imaging口頭発表(一般)
- 日本材料学会第60期学術講演会, 2011年05月, 日本語, 日本材料学会, 吹田市, 国内会議高輝度放射光CTによるねじり疲労き裂の進展・分岐挙動の観察と評価口頭発表(一般)
- 日本材料学会第60期学術講演会, 2011年05月, 日本語, 日本材料学会, 吹田市, 国内会議オーステナイト系ステンレス鋼の疲労試験における散逸エネルギ評価口頭発表(一般)
- 日本機械学会関西学生会平成22年度学生員卒業研究発表講演会(2011年3月18日, 京都工芸繊維大学), 2011年03月, 日本語, 日本機械学会, 京都市, 国内会議放射光μCT画像に基づいた三次元再構成モデルを用いたねじり疲労き裂進展挙動の評価口頭発表(一般)
- 日本機械学会関西支部第86期定時総会講演会, 2011年03月, 日本語, 日本機械学会, 京都市, 国内会議放射光μCTイメージングを用いたねじり疲労き裂進展挙動の観察と評価口頭発表(一般)
- 日本機械学会関西支部 第86期定時総会講演会, 2011年03月, 日本語, 日本機械学会, 京都市, 国内会議散逸エネルギ計測に基づく疲労損傷過程の評価口頭発表(一般)
- 日本機械学会関西学生会平成22年度学生員卒業研究発表講演会(2011年3月18日, 京都工芸繊維大学), 2011年03月, 日本語, 日本機械学会, 京都市, 国内会議回折コントラストイメージを用いた三次元結晶マッピング法の開発口頭発表(一般)
- 日本機械学会関西学生会平成22年度学生員卒業研究発表講演会(2011年3月18日, 京都工芸繊維大学), 2011年03月, 日本語, 日本機械学会, 京都市, 国内会議黄銅の微細結晶粒材料の作製とその疲労強度評価口頭発表(一般)
- 日本機械学会関西支部第86期定時総会講演会, 2011年03月, 日本語, 日本機械学会, 京都市, 国内会議オーステナイト系ステンレス鋼の疲労損傷過程における加工誘起マルテンサイト変態挙動の観察と評価口頭発表(一般)
- 日本機械学会関西学生会平成22年度学生員卒業研究発表講演会(2011年3月18日, 京都工芸繊維大学), 2011年03月, 日本語, 日本機械学会, 京都市, 国内会議オーステナイト系ステンレス鋼の加工誘起マルテンサイト変態を用いた疲労損傷評価口頭発表(一般)
- 日本機械学会関西支部機械の強度と形態研究懇話会第7 回NCP フォーラム, 2011年02月, 日本語, 日本機械学会, あわら市, 国内会議散逸エネルギ計測に基づく疲労損傷過程の評価口頭発表(一般)
- International Conference on Experimental Mechanics (ICEM 2010), 2010年12月, 英語, Asian Society on Experimental Mechanics, Kuala Lumpur, Malaysia, 国際会議Initiation and Growth of Corrosion Fatigue Pits and Cracks in High Strength Aluminum Alloy Observed by Micro Computed-tomography Using Ultra-bright Synchrotron Radiation口頭発表(一般)
- 日本機械学会 M&M2010材料力学カンファレンス, 2010年10月, 日本語, 日本機械学会, 長岡市, 国内会議回折コントラストイメージを用いた結晶構造解析口頭発表(一般)
- 14th International Conference on Experimental Mechanics (ICEM 14), 2010年07月, 英語, Eura SEM, Poitiers, France, 国際会議Observations of corrosion pits and cracks in corrosion fatigue of high strength aluminum alloy by computed-tomography using synchrotron radiation口頭発表(一般)
- 10th International Fatigue Congress (Fatigue 2010), 2010年06月, 英語, Institute of Physics of Materials ASCR, Prague, Czech Republic, 国際会議Observation of crack propagation under torsion fatigue tests by synchrotrpn mCT imaging口頭発表(一般)
- 日本機械学会関西支部第85期関西学生会学生員卒業研究発表講演会., 2010年03月, 日本語, 日本機械学会関西支部, 神戸市, 国内会議高分子圧電材料を用いたスマートシートセンサの開発口頭発表(一般)
- 日本機械学会関西支部第85期関西学生会学生員卒業研究発表講演会., 2010年03月, 日本語, 日本機械学会関西支部, 神戸市, 国内会議高温超伝導SQUID顕微鏡を用いたプリント配線の非破壊欠陥検査法の開発口頭発表(一般)
- 日本機械学会関西支部第85期関西学生会学生員卒業研究発表講演会., 2010年03月, 日本語, 日本機械学会関西支部, 神戸市, 国内会議オーステナイト系ステンレス鋼の疲労損傷によるマルテンサイト変態挙口頭発表(一般)
- 日本機械学会関西支部第85期関西学生会学生員卒業研究発表講演会., 2010年03月, 日本語, 日本機械学会関西支部, 神戸市, 国内会議Zr基バルク金属ガラスのKISCC近傍におけるき裂伝ぱ挙動口頭発表(一般)
- The 4th International Conference on Experimental Mechanics, 2009年11月, 英語, Asian Conference on Experimental Mechanics, Singapore, 国内会議Observation of Fretting Fatigue Cracks by Micro Computed-Tomography using Ultrabright Synchrotron Radiation口頭発表(一般)
- M&Mカンファレンス2009, 2009年07月, 日本語, 日本機械学会, 札幌市, 国内会議放射光μCTイメージングによる腐食疲労損傷の観察口頭発表(一般)
- 日本機械学会M&M2009 材料力学カンファレンス, 2009年07月, 日本語, 日本機械学会, 札幌市, 国内会議オーステナイト系ステンレス鋼の疲労損傷によるマルテンサイト変態挙動の観察口頭発表(一般)
- M&Mカンファレンス2009, 2009年07月, 日本語, 日本機械学会, 札幌市, 国内会議オーステナイト系ステンレス鋼の疲労損傷によるマルテンサイト変態挙動の観察口頭発表(一般)
- The 12th International Conference on Fracture (ICF-12), 2009年07月, 英語, International Conference on Fracture, Ottawa, Canada, 国内会議Observation of Fretting Fatigue Cracks by Micro Computed Tomography with Synchrotron Radiation口頭発表(一般)
- 12th International conference on fracture, 2009年07月, 英語, Natural Resource Canada, Ottawa,Canada, 国際会議Observation of Fretting fatigue Cracks by Micro Computed Tomography with Synchrotron Radiation口頭発表(一般)
- 日本材料学会第58期学術講演会, 2009年05月, 日本語, 日本材料学会, 松山市, 国内会議放射光マイクロCTイメージングによるねじり疲労き裂の観察口頭発表(一般)
- 関西学生会平成20年度学生員卒業研究発表講演会, 2009年03月, 日本語, 日本機械学会関西支部, 東大阪市, 国内会議放射光μCTを用いたTi合金におけるねじり疲労き裂進展挙動の観察口頭発表(一般)
- 第84期定時総会講演会, 2009年03月, 日本語, 日本機械学会関西支部, 東大阪市, 国内会議高温超電導SQUID顕微鏡を用いた非破壊評価法の開発口頭発表(一般)
- 関西学生会平成20年度学生員卒業研究発表講演会, 2009年03月, 日本語, 日本機械学会関西支部, 東大阪市, 国内会議高温超伝導SQUID 顕微鏡の高分解能化への検討口頭発表(一般)
- 関西学生会平成20年度学生員卒業研究発表講演会, 2009年03月, 日本語, 日本機械学会関西支部, 東大阪市, 国内会議オーステナイト系ステンレス鋼の疲労損傷によるマルテンサイト相変態挙動の観察口頭発表(一般)
- (社)日本材料学会 第45回X線材料強度に関する討論会, 2008年12月, 日本語, 日本材料学会, 東京都, 国内会議高輝度放射光を利用したμCT法による金属材料中の組織およびき裂の観察[招待有り]口頭発表(招待・特別)
- 日本材料学会・第29回疲労シンポジウム, 2008年11月, 日本語, 日本材料学会, 京都市, 国内会議放射光を用いたμCTイメージングによるフレッティング疲労き裂の観察口頭発表(一般)
- SPring-8応力評価実用化研究会及び疲労損傷評価研究会合同研究会, 2008年11月, 日本語, SPring-8利用推進協議会, 大阪, 国内会議高輝度放射光マイクロCT法による介在物・疲労き裂・腐食ピットの観察口頭発表(招待・特別)
- Spring-8応力評価実用化研究会(第17回)及び疲労損傷評価研究会(第6回)合同研究会, 2008年11月, 日本語, Spring-8利用推進協議会, 大阪市, 国内会議高輝度放射光マイクロCT法による介在物・疲労き裂・腐食ピットの観察口頭発表(招待・特別)
- 日本材料学会・第29回疲労シンポジウム, 2008年11月, 日本語, 日本材料学会, 京都市, 国内会議高輝度放射光CT法による腐食疲労ピットおよびき裂の発生と成長の観察口頭発表(一般)
- M&M2008材料力学カンファレンス, 2008年09月, 日本語, 日本機械学会, 草津市, 国内会議高温SQUIDを用いたプリント配線の非破壊欠陥検出口頭発表(一般)
- 第4回マイクロマテリアルシンポジウム, 2008年09月, 日本語, 日本材料学会, 東京, 国内会議高温SQUIDを用いたプリント配線の欠陥検出口頭発表(一般)
- M&M2008材料力学カンファレンス, 2008年09月, 日本語, 日本機械学会, 草津市, 国内会議オーステナイト系ステンレス鋼の繰返し変形による磁気特性変化に及ぼす応力比の影響口頭発表(一般)
- 日本材料学会第57期通常総会・学術講演会, 2008年05月, 日本語, 日本材料学会, 鹿児島市, 国内会議SUS30鋼の疲労損傷による磁気特性変化に及ぼす応力比の影響口頭発表(一般)
- 電磁力関連のダイナミクスシンポジウム, 2008年05月, 日本語, 日本AEM学会, 大分市, 国内会議SUS304鋼の高サイクル疲労損傷による磁気特性変化に及ぼす応力比の影響口頭発表(一般)
- 関西学生会卒業研究発表会, 2008年03月, 日本語, 日本機械学会, 豊中, 国内会議放射光イメージングによる高強度アルミニウム合金の腐食疲労き裂の観察口頭発表(一般)
- 関西学生会卒業研究発表会, 2008年03月, 日本語, 日本機械学会, 豊中市, 国内会議SQUIDを用いたプリント配線内欠陥による磁場分布変化の測定口頭発表(一般)
- 日本機械学会関西支部第83期定時総会講演会, 2008年03月, 日本語, 日本機械学会/The Japan Society of Mechanical Engineers, 豊中市, 国内会議SQUIDを用いたプリント配線の非破壊欠陥検出法の開発口頭発表(一般)
- 2008 M&M International Symposium for Young Researchers, 2008年03月, 英語, Japan Society of Mechanical Engineers, Wakayama, 国際会議Observation of martensitic transformation in fatigue by the change in magnetism口頭発表(一般)
- 日本機械学会創立110周年記念2007年度年次大会, 2007年09月, 日本語, 日本機械学会/The Japan Society of Mechanical Engineers, 吹田市, 国内会議磁気特性変化を用いたSUS04鋼の疲労損傷検出口頭発表(一般)
- 日本機械学会創立110周年記念2007年度年次大会, 2007年09月, 日本語, 日本機械学会/The Japan Society of Mechanical Engineers, 吹田市, 国内会議SQUIDを用いた電流内欠陥の非破壊検出口頭発表(一般)
- Fourth International Conference on Very High Cycle Fatigue, 2007年08月, 英語, The Metallurgical Society ofAIME, Ann Arbor, USA, 国際会議Observation of Inclusions and Defects in Steels by Micro Computed-tomography using Ultrabright Synchrotron Radiation口頭発表(一般)
- 日本材料学会第56期学術講演会, 2007年05月, 日本語, 日本材料学会, 名古屋市, 国内会議SUS304鋼のき裂発生過程における磁気特性変化の観察口頭発表(一般)
- 第56期材料学会総会, 2007年05月, 日本語, 日本材料学会, 名古屋市, 国内会議SUS304鋼におけるき裂発生過程の磁気特性変化の観察口頭発表(一般)
- 第28回疲労シンポジウム, 2006年11月, 日本語, 日本材料学会, 名古屋市, 国内会議SPring-8のマイクロトモグラフィによる鋼中の介在物および欠陥観察口頭発表(一般)
- 第3回マイクロマテリアルシンポジウム, 2006年09月, 日本語, 日本材料学会, 同志社大学・京都, 国内会議高輝度放射光のμ-X線CTイメージングを用いた高強度鋼中の介在物およびき裂の定量的評価口頭発表(一般)
- 2006年度日本機械学会年次大会, 2006年09月, 日本語, 日本機械学会, 熊本大学・熊本, 国内会議SUS304鋼における疲労過程の磁気特性変化を用いた疲労損傷評価口頭発表(一般)
- 2nd Workshop on New Methods of Damage and Failure Analysis of Structural Parts, 2006年09月, 英語, Technical University of Ostrava, Technical University of Ostrava, Czech, 国際会議Quantitative Analysis of Inclusions and Fatigue Cracks in Steel by X-ray Computed Tomography Using Ultra-bright Synchrotron Radiation口頭発表(招待・特別)
- 第55期材料学会総会, 2006年05月, 日本語, 日本材料学会, 長岡技術科学大学, 国内会議SUS304鋼における疲労過程の磁気特性変化口頭発表(一般)
- 第54期材料学会総会学術講演会, 2005年05月, 日本語, 日本材料学会, 仙台市民会館, 国内会議SUS304鋼における疲労損傷の磁気力顕微鏡による観察口頭発表(一般)
- M&M信州スプリングシンポジウム, 2005年03月, 日本語, 未記入, 未記入, 国内会議受動型電気ポテンシャルCT法によるき裂同定および欠陥モニタリング口頭発表(一般)
- 第3回評価・診断に関するシンポジウム, 2005年, 日本語, 未記入, 未記入, 国内会議受動型電気ポテンシャルCT法による複合材内はく離状欠陥の同定およびモニタリング口頭発表(一般)
- 日本機械学会関西支部材力談話会, 2005年, 日本語, 未記入, 未記入, 国内会議受動型電気ポテンシャルCT法によるき裂同定口頭発表(一般)
- M&M2004材料力学カンファレンス, 2005年, 日本語, 未記入, 未記入, 国内会議圧電弾性練成問題の境界要素逆解析によるピエゾ材料を用いた接触圧力分布の推定口頭発表(一般)
■ 共同研究・競争的資金等の研究課題
- 日本学術振興会, 科学研究費助成事業, 基盤研究(C), 神戸大学, 2024年04月01日 - 2027年03月31日赤外線CTによる5D(3D+時系列+ハイパースペクトル)漏洩ガス可視化手法の開発
- 日本学術振興会, 科学研究費助成事業, 基盤研究(B), 静岡大学, 2022年04月01日 - 2025年03月31日4次元的損傷分散概念に基づく多機能ヘテロ金属創製原理の創発
- 日本学術振興会, 科学研究費助成事業, 基盤研究(B), 神戸大学, 2021年04月01日 - 2024年03月31日防食塗装の経年劣化を遠隔から定量評価できる目視を超越した赤外分光計測法の創生橋梁,石油タンク,配管等のインフラ構造物の長寿命化ならびにライフサイクルコストの削減には,予防保全の導入が不可欠である.鋼構造物の腐食に対する予防保全での最重要課題は,限られたリソースの下で,鋼構造物の腐食に対する予防保全を実施するため,重防食塗装の劣化を早期に遠隔から非接触・非破壊で,効率的かつ高精度に検知するとともに,劣化進行度を定量的に評価できる非破壊評価法を開発することである.そこで,本研究では,重防食塗装膜が有する赤外光の分光反射・吸収・透過特性に着目し,赤外線カメラを用いた分光画像計測ならびに分光特性に基づくマルチスペクトル逆問題解析に基づき,遠隔から構造物の重防食塗装の早期劣化を定量的に評価できる計測法を開発する.2021年度は,そのためのハードウエアの製作ならびに塗装膜の赤外線計測に関する基礎検討を行った. まず,計測に用いるハードウエアとして,対象物の分光特性を画像化できる赤外分光画像計測装置を近赤外線カメラを基礎に試作した.また,塗膜劣化試験体に対して,太陽光を用いるパッシブ計測および照明光を用いるアクティブ計測により,塗膜劣化部位の検出および塗膜の残存厚さの定量評価を試行した.その際の計測精度の向上を目的として,一定周期で変動する照明の下での近赤外線強度変動データをロックイン計測する,アクティブロックイン計測法を開発した.さらに,アクティブロックイン計測法の有用性を実験室レベルでの試験体を用いた計測,ならびに実鋼橋梁での現場計測を通じて実験的に検証した.
- 日本学術振興会, 科学研究費助成事業, 基盤研究(S), 立命館大学, 2018年06月11日 - 2023年03月31日調和組織材料の革新的力学特性発現機構の解明と次世代構造材料創製指導原理の創発社会基盤の骨格とも言える構造用金属材料には、高い強度と大きな延性が同時に要求される。しかし、“Considere's criterion”が19世紀の終わりに発表されて以来、金属材料の強度と延性は理論上、両立しない性質であり、両者は二律背反であることが常識とされてきた。 これに対し、研究代表者は「調和組織材料」の創製に成功し、調和組織材料が高強度と高延性を両立する普遍的な性質を有することを示した。そして、調和組織材料の研究を進める中で、通常の均一材料には見られない様々な特異現象が見つかった。本研究では、多彩な学術分野の研究者が結集し、ミクロからマクロに拡がる転位/粒界/周期構造の関連性を系統的に明らかにすることを目指し、調和組織材料の「高強度と高延性・高靱性の両立」をはじめとする様々な特異な力学特性を、大型放射光施設や最先端の力学特性・組織解析手法を駆使して解明しつつある。 これまでの特筆すべき成果として、「シナジー硬化現象」や「新たな延性発現機構」を見出した。「シナジー硬化(Synergy Extra Hardening)」は、従来のHall-Petch関係に依らない、特異な強度上昇が見られる現象である。また、「新たな延性発現機構」とは、強度が上昇すれば全伸びに占める局部伸びが低下する、という従来常識に反して、高強度化しても局部伸びは低下せず、その結果、高延性に結びつく現象で、加工硬化の増大による延性増加とは異なる、新しい延性発現機構である。「降伏とは何か?」、「延性とは何か?」という学術的に意義深い問いを改めて突きつける成果が得られた。これまでの材料科学の知識・常識を打ち破るパラダイムシフトが期待できる成果である。
- 日本学術振興会, 科学研究費助成事業, 基盤研究(B), 静岡大学, 2019年04月01日 - 2022年03月31日マルチスケール計測による高機能ヘテロ構造材料の4次元損傷評価金属材料の「強さ」と「しなやかさ」の両立を達成するため,しなやかな粗大粒組織の周りに強い微細粒組織をネットワーク状に周期配置させた「3次元ヘテロ構造材料」を創製した.本研究では,ヘテロ構造材料のミクロ・マクロ変形の双方を捉えるマルチスケール計測法を構築し,3次元ヘテロ構造における材料損傷挙動の時間的変化を評価(4次元材料損傷評価)した.具体的には,3次元ヘテロ構造を有する各種金属材料の疲労損傷メカニズムについて検討を加え,ネットワーク相に損傷が集中した結果,弱い粗大結晶粒組織が損傷しにくいことを明らかとした.
- 日本学術振興会, 学術研究助成基金助成金/基盤研究(C), 基盤研究(C), 神戸大学, 2018年04月 - 2021年03月電子後方散乱回折(EBSD)解析により双晶帯発生,双晶帯消滅,および疲労き裂発生のメカニズムを解明するため,底面が負荷方向に平行(c-軸が表面に垂直)な集合組織をもった試験片と結晶方位がランダムなマグネシウム合金AZ31伸展材より作成した試験片を用いて,引張-圧縮-引張,圧縮-引張-圧縮-引張-圧縮,圧縮- 圧縮の三種類の繰り返し応力を適用した.その結果,集合組織材では,引張応力下では双晶帯は発生しなかったが,圧縮応力下では双晶帯が発生することをEBSD 観察によって確かめた.また,圧縮応力下で発生した双晶帯は,引張応力下で全て消滅した.再度圧縮応力を負荷したところ,最初の圧縮負荷によって双晶帯が 発生したのと同じ場所に再度双晶帯が発生するもの,最初の圧縮負荷によって双晶帯が発生した場所に二回目の圧縮負荷では双晶帯が発生しないもの,最初の圧 縮負荷によって双晶帯が発生しなかった場所に二回目の圧縮負荷では双晶帯が発生したものがあることが分かった.したがって,双晶帯とその消滅は完全には可 逆的ではなく,不可逆なものもあることが分かった.一方,結晶方位がランダムな場合,引張応力下,圧縮応力下のいずれでも双晶帯が発生した.また,この場 合,圧縮応力下で発生した双晶帯は,後続の引張負荷によって消滅しなかった.また,双晶消滅の生じない圧縮-圧縮の繰返し負荷を多数回繰り返した場合,底 面の法線(c-軸)が負荷軸方向に揃った集合組織に変化した.競争的資金
- 科学研究費補助金/基盤研究(B), 2018年04月 - 2021年03月競争的資金
- 科学研究費補助金/基盤研究(B), 2017年04月 - 2020年03月, 研究代表者競争的資金
- 学術研究助成基金助成金/挑戦的萌芽研究, 2016年04月 - 2018年03月競争的資金
- 科学研究費補助金/基盤研究(B), 2014年04月 - 2017年03月競争的資金
- 科学研究費補助金/基盤研究(B), 2014年04月 - 2017年03月競争的資金
- 学術研究助成基金助成金/基盤研究(C), 2013年04月 - 2016年03月, 研究代表者競争的資金
- 日本学術振興会, 科学研究費助成事業, 基盤研究(A), 北海道大学, 2012年04月01日 - 2015年03月31日高強度チタン合金における内部起点型微小き裂の可視化と超高サイクル疲労機構の解明超高サイクル域における軸荷重疲労試験が行われ,放射光μCTイメージングにより材料内部に発生する微小き裂が観察された.内部き裂周囲の環境がき裂進展に及ぼす影響を明らかにするため,da/dNと応力拡大係数範囲の関係が測定され,真空中表面き裂のそれと比較された.その結果,内部き裂は1.0E-10m/cycleの極めて低速で進展するのに対し,表面に到達した後のき裂は1.0E-7m/cycle 程度の高速で進展することがわかった.内部き裂の進展速度は真空中表面き裂の進展速度に一致し,内部き裂周囲の真空に類似した環境が超高サイクル疲労における内部き裂進展過程に大きな影響を与えることが明らかとなった.
- 日本学術振興会, 科学研究費補助金/若手研究(B), 若手研究(B), 神戸大学, 2010年 - 2012年, 研究代表者本研究では,CTイメージング技術を拡張した,結晶粒形状および結晶方位を三次元的に可視化する結晶3D マッピング法の一つである回折コントラストトモグラフィ(DCT)の開発を行った.まず日本の放射光施設 SPring-8における測定条件について検討を行い,アルミニウム合金,ステンレス鋼および工業用純鉄に適用し,本手法により結晶構造を解析できることを明らかにした.回折コントラストの測定時に得られる回折の拡がり角に着目すると,静的な引張負荷および繰返し負荷の増加とともに回折の拡がり角が大きくなることが分かった.以上のことから DCTによる結晶 3Dマッピング法および回折の拡がり角を疲労損傷評価パラメータとして用いることにより,き裂発生につながる疲労損傷およびクリープ損傷を評価できる可能性があることが分かった.競争的資金
- 科学研究費補助金/基盤研究(B), 2011年競争的資金
- 科学研究費補助金/基盤研究(B), 2011年競争的資金
- 日本学術振興会, 科学研究費助成事業, 基盤研究(C), 神戸大学, 2008年 - 2010年2光子吸収内部硬化型マイクロ光造形法によるナノ繊維強化光硬化樹脂の開発と評価表面吸収の著しい紫外線ではなく,より透過性の高いレーザ光を用いたマイクロ光造形法により,カーボンナノ繊維強化光硬化性樹脂複合材料を作製した.その結果,繊維体積含有率が1mass%以下でしか複合材料が作製できなかった紫外線法に比べ,体積含有率10mass%でも複合材料の作製が可能となり,内部空孔もより小さくできた.引張強さは体積含有率5mass%で最大となり,樹脂単体の2倍以上の値が得られた.
- 日本学術振興会, 科学研究費補助金/基盤研究(C), 基盤研究(C), 神戸大学, 2008年 - 2010年繰り返し圧延法によって,平均結晶粒径微細結晶粒1.0μmのα黄銅微細結晶粒材を作成することに成功した.結晶粒径と引張り強さ,疲労限度の間にはHall-Petchの関係が成立し,通常の結晶粒材 よりも著しく強度の高い材料を開発できた.また,工業用純鉄細線を用いて引張試験,疲労試験を行った結果,線径が小さくなると降伏現象が消失することを発見した.降伏現象の消失が疲労挙動にも大きく影響を及ぼしていることも明らかになった.さらに,Zr基バルク金属ガラスを用いて疲労試験を行った結果,バルク金属ガラスは板厚方向に強度の不均質性を有することと,切欠きに極めて敏感であることがわかった.競争的資金
- 日本学術振興会, 科学研究費補助金/若手研究(B), 若手研究(B), 神戸大学, 2008年 - 2009年, 研究代表者磁気特性の評価をもとに疲労損傷を評価することを目的として,疲労過程中のマルテンサイト体積率をフェライトスコープにより測定し,マルテンサイト相に起因する漏洩磁界変化をMIセンサにより測定した. 塑性ひずみ幅とマルテンサイト体積率の変化率との間に対応関係が見られ,これらから累積ひずみをマルテンサイト体積率から推定できる可能性があることが分かった.したがってマルテンサイト体積率の測定から疲労損傷程度を評価できるものと期待される. マルテンサイト体積率測定の高感度化のためにMIセンサよりも高感度なSQUID顕微鏡を用いた磁気顕微鏡を構築した.さらに微小き裂の発生および進展の観察のためにSPring-8の放射光を用いた・CTイメージングを構築した.競争的資金
- 日本学術振興会, 科学研究費補助金/基盤研究(C), 基盤研究(C), 神戸大学, 2006年 - 2007年本研究課題は,薄膜化による応答速度向上が検討され,マイクロマシン用として期待が高まっているTiNi形状記憶合金(SMA)薄膜マイクロアクチュエータの実用化を促進するために,薄膜化に伴って特に問題となることが予想される,水素環境下におけるTiNi合金の遅れ破壊の寿命,および形状回復機能の劣化寿命を明らかにし,その寿命評価法を検討することを目的としたものである. 積層圧延法,およびスパッタリング法で作製した二種類のTiNi薄膜マイクロアクチュエータ(厚さ4〜16μm)に対して水素チャージを行い,構築した微小材料試験システムを用いてSSRT法による遅れ破壊試験を実施した.二種類の薄膜マイクロアクチュエータいずれにおいても,水素チャージ時間が長くなるとともに強度が低下した.同じ水素チャージ時間で比べた場合,より薄いマイクロアクチュエータのほうが強度低下が著しかった.この挙動は,水素チャージ時間とともに増加する拡散水素量に対応していた.AFM観察の結果,遅れ破壊では表面に発生した脆性的な微小き裂が急速に進展することで破壊に至ると考えられた.同じ薄膜マイクロアクチュエータに対して,水素チャージ環境下での繰返し形状回復試験を実施した.膜厚が小さくなるにつれて回復応力と回復ひずみ率の低下が著しくなった.また,水素チャージ環境下での疲労試験で得られたS-N曲線は,繰返し速度が低い場合ほど短寿命側にシフトし,かつ,より薄いマイクロアクチュエータのほうが短寿命であった.破断時間と最大応力の関係は繰返し速度に依存せず,完全に時間依存型の水素環境劣化破壊であることがわかった.さらに,微小TiNi合金アクチュエータの関連技術として,TiNi細線を利用した高出力のアクチュエータの開発を試み,細線を強化材とする薄板型の複合材料アクチュエータを作製・評価した.競争的資金
- 日本学術振興会, 科学研究費補助金/若手研究(B), 若手研究(B), 神戸大学, 2006年 - 2007年, 研究代表者1.SUS304鋼における疲労過程の漏洩磁界分布の観察 疲労過程における磁気特性変化を調べるために,SUS304鋼についての平面曲げ疲労試験を行い,漏洩磁界分布の変化を観察した.平成18年度では両振り(R=-1)で実験を行った.平成19年度では応力比を変化させて疲労試験を行い,応力比による影響を検討した結果,次のような知見を得た.(1)応力比R=-0.5の場合においてもR=-1の場合と同様に,負荷繰返し数の増加と伴に応力集中部において漏洩磁界の増加または減少が観察された.(2)疲労過程における繰返し変形によるマルテンサイト変態への影響を調べるために,ひずみゲージを用いてひずみ幅の変化を測定したところ,ひずみ幅の増加および減少と磁界変化率の変化に対応関係が見られた.(3)R=-1の場合と比較して,R=-0.5の場合における疲労過程初期段階の漏洩磁界の変化は小さい. ひずみ変化と磁気特性変化に対応関係が見られることから,疲労過程における加工硬化および加工軟化などの組織変化を磁気特性変化により評価できる可能性があることがわかった. 2.SQUIDを用いた磁界分布の測定 SQUID(超伝導量子干渉素子)は,地磁気の5000万分の1以下の磁界を検出できる高感度磁気センサであり,従来の磁気センサでは検出できなかった欠陥による微小な磁界変化を捉えることが出来る可能性がある.本研究では,SQUIDを用いた計測システムを構築し,その動作特性について検討を行った.その結果,SQUIDを用いて得られた200μm幅の電流路およびそのなかの欠陥の影響による磁界変化を検出できることがわかった.SQUIDを用いれば,高感度かつ高分解能でSUS304鋼内の磁性相を検出できると考えられる.競争的資金
- 日本学術振興会, 科学研究費助成事業, 特別研究員奨励費, 神戸大学, 2004年 - 2004年リアルタイム・ヘルスモニタリングのためのパッシブ電気ポテンシャルCT法の開発得られた研究実績を以下に示す. 1.圧電弾性連成問題の境界要素解析プログラムの作成 ピエゾ効果による三次元弾性場・三次元電気ポテンシャル場の連成解析のための境界要素解析プログラムを新たに作成した.境界要素解析プログラムによれば,有限要素解析と比較して,少ない節点で精度良く電気ポテンシャル場を計算することができ,複雑な形状の対象に関する電気ポテンシャル分布を精度良く解析できる可能性があることが確認できた.本解析プログラムを用いて接触圧力分布の推定を行った.ピエゾ材料では,電気的な境界値と機械的な境界値が連成しているため,電気的な情報から変位または表面力などの機械的な情報を逆問題的に推定できるものと考えられる.電気ポテンシャル分布から計測面の背面における接触圧力分布を推定する数値シミュレーションを行ったところ,接触圧力分布の推定が可能であることがわかった. 2.炭素繊維強化複合材内のはく離状欠陥の同定に関する実験的検討 炭素繊維強化複合材(三菱重工業製)の内部に人工はく離状欠陥を導入し,この試験体に対してはく離状欠陥の同定を試みた.試験体にピエゾフィルムを貼り付け,3点曲げ変形を与えた場合に,ピエゾフィルム上の電気ポテンシャル分布は,はく離先端の存在領域において特徴的な変化を示した.はく離の層間深さを変化させた3種類の試験体(測定面から板厚比1/4,1/2および3/4の層間深さ)についてそれぞれ同様の実験を行った.その結果,はく離の層間深さに応じてポテンシャル分布傾向が変化することが確認された. 逆問題解析を適用して,測定結果からはく離の寸法および位置の推定を試みた.その結果,はく離の寸法および位置,すなわち損傷領域は精度良く推定できることがわかった.はく離の層間深さに関しては,測定面から近いか,板厚中央より深いかの大まかな層間深さの推定が可能であることがわかった.
研究シーズ
■ 研究シーズ- 赤外線サーモグラフィを用いた構造安全性評価シーズカテゴリ:ものづくり技術(機械・電気電子・化学工業), 自然科学一般研究キーワード:疲労強度, 非破壊評価, 構造設計研究内容:機赤外線サーモグラフィの温度変動を計測すると、作用している力を非接触で面計測できます。この特徴から大きな構造物も稼働中の負荷状態を評価でき、さらに望遠レンズを用いると遠方から計測することができます。また構造物の強度設計に必要な疲労強度評価には、多数の試験片に対する長時間の耐久試験を行うなど、多くのコストと時間を要します。本研究では、応力のその場計測手法や疲労強度を迅速に推定する手法の開発を行っています。