研究者紹介システム
| 小川 裕樹 |  |
| オガワ ユウキ | |
| 大学院工学研究科 機械工学専攻 | |
| 助教 | |
| 機械工学関係 |
研究活動
研究キーワード
研究分野
受賞
2019年 溶接構造シンポジウム2019 シンポジウム奨励賞
2018年 日本材料学会 第67期学術講演会優秀講演発表賞
2016年 日本機械学会 若手優秀講演フェロー賞
2016年 自動車技術会 大学院研究奨励賞
論文
- Elsevier BV, 2022年02月, International Journal of Fatigue, 155, 106597 - 106597
[査読有り]
研究論文（学術雑誌）
- Springer Science and Business Media LLC, 2022年01月21日, Welding in the World
[査読有り]
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27日, Engineering Proceedings, 8 (1), 33 - 33[査読有り]
研究論文（国際会議プロシーディングス）
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25日, Engineering Proceedings, 8 (1), 26 - 26[査読有り]
研究論文（国際会議プロシーディングス）
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19日, Engineering Proceedings, 8 (1), 6 - 6[査読有り]
研究論文（国際会議プロシーディングス）
Purpose: Polyetheretherketone (PEEK), a high-strength, aesthetic, and non-allergic thermoplastic polymer, recently became a candidate for replacing metallic components in dental prosthesis. However, as PEEK is flexible, the need for retention presents a key challenge in terms of its clinical application. In this study, clasps prepared using PEEK were optimized and evaluated to provide the mechanical properties required by dentures.Methods: Seventy-two three-dimensional rod-shape models, based on four thickness/width ratios, three base widths, and six taper ratios were created. These models were analyzed using finite-element methods to determine which modified clasp arm shape provided the most appropriate mechanical properties. Three shape-optimized PEEK specimens and one standard-shape Co-Cr alloy specimen were then fabricated. Constant-displacement fatigue testing was performed to calculate load values and deformations after ten years of clinical use.Results: Shape optimization indicated a maximum stress concentration that was consistently located at the base of the specimen, a correlation between mean load values and thickness that was greater than that with the width, and a correlation between taper ratio and mean load values. Fatigue testing showed that although PEEK exhibited significantly lower average load values than the Co-Cr alloy, these were sufficient for clinical use. All specimens exhibited significant deformation during the first period of cycling; however, there was no significant difference in the deformation between the two materials after fatigue testing.Conclusions: PEEK exerts fewer stresses on abutments compared to standard-alloy clasps, provides adequate retention, and satisfy aesthetic demands, indicating that PEEK presents a promising alternative to conventional metal clasps. (C) 2019 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.
ELSEVIER IRELAND LTD, 2020年07月, JOURNAL OF PROSTHODONTIC RESEARCH, 64 (3), 250 - 256, 英語[査読有り]
研究論文（学術雑誌）
Manufacturers have been promoting multimaterial designs. So the dissimilar material welding methods are being developed. Especially, heat welding technology, which is a direct joining by local heating, has been focussed. Therefore, this study used a heat welding technology for friction stir spot welding of aluminium alloy and carbon fibre-reinforced plastic. This study investigated the effect of changes to jig constraint of joined members on the fatigue properties of joints. Also, the fatigue life estimation was carried out by considering the singular stress at the welding joint interface. As a result, the fatigue strength of joint in a less constrained state is higher than that in a more constrained state. The singular stress intensity at the slit tip was uniformly predicted by the differences in welding parameters of joints.
WILEY, 2020年05月, FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES, 英語[査読有り]
研究論文（学術雑誌）
Reducing the weight of automobile bodies would help counteract environmental problems caused by greenhouse gas emissions by improving fuel efficiency. Multi-material structures have been investigated to construct an automobile body structure composed of steel in combination with lightweight metal materials and carbon-fiber-reinforced plastic. Thus, it is necessary to develop high-quality bonding techniques that can join dissimilar materials as quickly as possible. To this end, adhesive bonding has attracted attention from the viewpoint of building multi-material structures. However, from the viewpoint of durability and reliability, it is regarded as a complementary technique used to support other industrial welding methods. Moreover, to further improve the strength of adhesive bonding, the surface conditions of the adherend must be considered. In this study, to improve the interfacial strength of adhesively bonded joints, laser patterning pre-processing was applied as a surface treatment. The fatigue properties of adhesively bonded joints were evaluated and compared with those of untreated joints. It was found that the static and fatigue strengths of the joints were improved by the laser patterning pre-processing. In particular, the joint strength was improved by removing the weak boundary layer from the entire adhesion surface with laser irradiation. Therefore, the laser patterning pre-processing method proposed in this study is a very promising process for achieving adhesively bonded joints with excellent fatigue properties.
This Paper was Originally Published in Japanese in J. Soc. Mater. Sci. Japan 68 (2019) 890–896.
公益社団法人 日本金属学会, 2020年, MATERIALS TRANSACTIONS, 61 (3), 469 - 474, 英語[査読有り]
One way of addressing environmental problems is to increase the use of light-weight materials in automobiles, such as the multi-material structure, which improves fuel economy and reduces pollution. However, it is necessary to develop a welding technique to join carbon fibre-reinforced plastic to metals to achieve a multi-material structure. So, this paper aims to shorten the welding time and to clarify the fatigue fracture mechanism of shear type friction stir spot welding joint between aluminium alloy and CFRP experimentally and analytically. As a result, the static and fatigue strength of the joint improved as the welding time increased due to the increase of total joint area to increased resin melting.
TAYLOR & FRANCIS LTD, 2019年04月, SCIENCE AND TECHNOLOGY OF WELDING AND JOINING, 24 (3), 235 - 242, 英語[査読有り]
研究論文（学術雑誌）
It is necessary for automobiles to reduce the weight of car bodies against environmental problems. As a countermeasure, a multi-material structure is required to construct the automobile body structure using not only steel but also light metal materials and carbon fiber reinforced plastic. So, it is necessary to produce high-quality welds applying to those dissimilar materials, as quickly as possible. Therefore, adhesive bonding has attracted attention from the viewpoint of building multi-material structures. However, from the viewpoint of durability and reliability, it is regarded as a complementary technique for other industrial welding methods. Moreover, to further improve the strength of adhesive bonding, the surface condition of the adherent is important. In this study, in order to improve the interfacial strength of adhesive bonded joint, the laser patterning preprocessing was applied as the surface treatment. So, the fatigue properties of adhesive bonded joints were evaluated to compare the untreated joints. As a result, the static and fatigue strength of the joints were improved by the laser patterning preprocessing. In particular, the joint strength was further improved by removing the weak boundary layer on the entire surface with the laser irradiation. Therefore, the laser patterning preprocessing proposed in this study is a very useful process for achieving the adhesive bonded joints with excellent fatigue properties.
公益社団法人 日本材料学会, 2019年, 材料, 68 (12), 890 - 896, 日本語[査読有り]
The purpose of this paper is to establish the welding technology for dissimilar materials of carbon fibre-reinforced plastic. Therefore, this study focused on friction stir spot welding, which can be simply substituted for spot welding which is widely used for welding of automobile body. In this study, friction stir spot welding was used to weld joints of carbon fibre-reinforced plastic and aluminium alloy, and the effect of aluminium alloy surface treatments on the fatigue properties and the fracture mechanism of dissimilar material joints were investigated experimentally and statistically. As a result, it is possible to create welding joints with high fatigue durability by using the surface treatments on the aluminium alloy.
TAYLOR & FRANCIS LTD, 2018年, SCIENCE AND TECHNOLOGY OF WELDING AND JOINING, 23 (1), 79 - 86, 英語[査読有り]
研究論文（学術雑誌）
This paper investigates an approach to evaluate the fatigue damage of FSSW cross-tension specimens under two-step force amplitude conditions. In fatigue tests with repeated two-step force amplitude, the fatigue limit of the welded joint disappeared. However, the fatigue damage evaluation using the modified Miner's rule erred too much on the side of safety, as the modified Miner's rule tends to overestimate the damage by applied forces below the fatigue limit. Thus, it was determined that, within the testing conditions used in this study, the fatigue damage evaluation using Haibach's method yielded an accurate evaluation. In the case where significant plastic deformation caused by the applied force occurred near the welded zone, the cumulative fatigue damage value based on Miner's rule was often larger than unity. Therefore, it is important to consider a cumulative damage estimation that takes into account the effect of pre-strain from the high force amplitude.
SPRINGER, 2015年06月, JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE, 24 (6), 2494 - 2502, 英語[査読有り]
研究論文（学術雑誌）
The authors have shown an approach to evaluate the fatigue fracture mechanism of cross-tension specimen welded using low carbon steel by friction stir spot welding (FSSW) with the focus on fatigue crack behaviour. Results show that, the fatigue limit of FSSW specimen was very low comparing to the tensile force of base metal and FSSW joint itself. The fatigue cracks initiated near the interface between two thin steel sheets under constant force amplitude conditions were observed in detail by the 3 dimensional observation method. The typical morphologies of 3-dimension were observed with constant low force amplitude level at 0.19 kN and high force amplitude level at 0.49 kN of each fatigue life. It is clear that a main crack initiated at the end of slit and fracture modes were independent on force amplitude level. And, FSSW joint used in this study requires the large and few number of cyclic loading to initiate the fatigue crack under low and high force amplitude level, respectively. Moreover, an evaluation method for the cumulative fatigue damage under variable force amplitude conditions was observed. The results show that, this method can be used to evaluate FSSW joint efficiency in automotive industry and other practical applications. (C) 2014 Published by Elsevier Ltd.
ELSEVIER SCIENCE BV, 2014年, 20TH EUROPEAN CONFERENCE ON FRACTURE, 3, 537 - 543, 英語[査読有り]
研究論文（国際会議プロシーディングス）
- Elsevier BV, 2022年09月, International Journal of Adhesion and Adhesives, 117, 103172 - 103172, 英語
[査読有り]
研究論文（学術雑誌）
MISC
- 技術情報協会, 2021年11月, 車載テクノロジー = Automotive technology, 9 (2), 39 - 44, 日本語アルミニウム/樹脂異種材料点接合の強度特性 (特集 自動車のマルチマテリアル化へ向けた異種材料の接着,接合技術)
- 日本出版制作センター, 2021年05月, JETI = ジェティ : Japan energy & technology intelligence : エネルギー・化学・プラントの総合技術誌, 69 (5), 79 - 83, 日本語アルミニウム/樹脂異種材料点接合の強度特性に及ぼす表面処理の影響 (特集 接着剤と異種材料接合技術)
自動車車体のマルチマテリアル化を実現するため，摩擦撹拌点接合を応用してアルミニウムと樹脂を接合する研究を進めている。本報では強度特性に及ぼすアルミニウム表面処理の影響をせん断引張試験，疲労試験，恒温恒湿試験，冷熱衝撃試験を行い調査した。化学結合力向上及びアンカー効果付与を主目的としたアルミニウム表面処理2種について比較評価を実施した結果，2種ともに無処理材と比較して強度特性や信頼性は向上し，バラツキも低減する傾向を示した。樹脂母材由来の接着性は材料によりさまざまであるが，本接合技術を使用する場合はアルミニウム表面処理と組み合わせて使用することでロバスト性の向上が可能である。
マツダ株式会社, 2020年, マツダ技報, 37, 81 - 85, 日本語
講演・口頭発表等
- 第28回 鉄道技術連合シンポジウム, 2021年12月赤外線サーモグラフィを用いた鉄道台車枠中の疲労き裂検出
- 日本材料学会, 第20回破壊力学シンポジウム, 2021年11月散逸エネルギに基づくレーザ溶接継手の疲労強度評価
- 第20回破壊力学シンポジウム, 2021年11月散逸エネルギ計測に基づいたき裂進展挙動の評価
- 16th International Workshop on Advanced Infrared Technology & Applications 2021, 2021年10月, 英語Evaluation of Fatigue Strength Based on Dissipated Energy for Laser Welds
口頭発表（一般）
- 16th International Workshop on Advanced Infrared Technology & Applications 2021, 2021年10月, 英語Quantitative deterioration evaluation of heavy-duty anticorrosion coating by near-infrared spectral characteristics
口頭発表（一般）
- 16th International Workshop on Advanced Infrared Technology & Applications 2021, 2021年10月, 英語4D reconstruction of leaked gas cloud based on computed tomography processing of multiple optical paths infrared measurement
口頭発表（一般）
- 日本機械学会 M&M2021材料力学カンファレンス, 2021年09月SPCC鋼板を母材とするレーザ溶接継手の散逸エネルギに基づく疲労強度評価
- 日本機械学会 M&M2021材料力学カンファレンス, 2021年09月Al/CFRP 異材点接合継手の二段変動荷重下における疲労特性評価
- 日本機械学会 M&M2021材料力学カンファレンス, 2021年09月赤外線可視化計測によって得られたガス雲形状に基づいた漏洩源推定
- 日本機械学会 M&M2021材料力学カンファレンス, 2021年09月可視ー赤外線ハイブリッド計測によるステンレス鋼の散逸エネルギ評価の高度化
口頭発表（一般）
- 日本材料学会 第70期通常総会・学術講演会, 2021年05月き裂先端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, 第96期定時総会講演会, 2021年03月テラヘルツイメージングによるGFRPの損傷評価
- 日本機械学会関西支部, 第96期定時総会講演会, 2021年03月散逸エネルギに基づいた摩擦撹拌接合部の疲労限度評価
- 日本機械学会関西支部, 第96期定時総会講演会, 2021年03月アクティブ温度ギャップ法を用いた疲労き裂検出法の開発
- 日本機械学会関西学生会, 2020年度学生員卒業研究発表講演会, 2021年03月アクティブ赤外線法を用いた鉄道台車枠の疲労き裂検出
- 日本機械学会関西学生会, 2020年度学生員卒業研究発表講演会, 2021年03月散逸エネルギに基づいた疲労強度評価の各種金属材料への適用
- 1st International Conference on Industrial Applications of Adhesives 2020, 2020年03月, 英語Mode I fracture toughness of a polyurethane adhesive
口頭発表（一般）
- 1st International Conference on Industrial Applications of Adhesives 2020, 2020年03月, 英語Effect of Adhesive Thickness on Fatigue Properties for Single Lap Bonded Joint with Different Types of Acrylic Adhesives
口頭発表（一般）
- 溶接構造シンポジウム2019, 2019年12月, 日本語アクリル系接着材を使用した接着接合継手の疲労特性に与える各種影響因子
口頭発表（一般）
- 5th International Conference on Structural Adhesive Bonding, 2019年07月, 英語Effect of adhesive thickness on the fatigue properties of bonded single-lap joints: in case of CFRP and polyurethane adhesive
口頭発表（一般）
- 日本材料学会 第68期通常総会・学術講演会, 2019年05月, 日本語Al合金/CFRP異材接合継手の変動荷重下における疲労強度評価
口頭発表（一般）
- 日本材料学会 M&M2018材料力学カンファレンス, 2018年12月, 日本語負荷形式の異なる引張せん断型レーザ接合継手の疲労強度評価
口頭発表（一般）
- 日本材料学会 第34回疲労シンポジウム, 2018年10月, 日本語冷間圧延鋼板SPCCを母材とする摩擦攪拌点接合継手の疲労特性に対する負荷形式の影響
口頭発表（一般）
- 2nd International Conference on Structural Integrity and Durability, 2018年10月, 英語Effect of Welding Parameters on Fatigue Strength of Joints Produced Friction Stir Spot Welding
口頭発表（一般）
- 日本材料学会 第67期通常総会・学術講演会, 2018年05月, 日本語Al合金/CFRP異材FSSW接合継手の疲労強度に関する接合条件の最適化
口頭発表（一般）
- 14th International Conference on Fracture, 2017年06月, 英語Fatigue properties of joints produced friction stir spot welding
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Al合金/CFRP摩擦撹拌点接合継手の疲労特性に及ぼすAl合金に付与した表面処理の影響
口頭発表（一般）
- 日本機械学会 2016年度年次大会, 2016年09月, 日本語Al合金/CFRP異材FSSW継手の疲労特性に及ぼすAl合金表面に付与した官能基の影響
口頭発表（一般）
- 日本材料学会第65期通常総会・学術講演会, 2016年05月, 日本語アルミニウム合金/CFRP異種材料間における摩擦撹拌点接合継手の疲労強度評価
口頭発表（一般）
- 日本材料学会 第64期通常総会・学術講演会, 2015年05月, 日本語摩擦撹拌点接合によるアルミニウム合金/CFRP異材接合継手の疲労強度評価
口頭発表（一般）
- 信頼性・破壊力学合同シンポジウム －第27回信頼性シンポジウム－ －第16回破壊力学シンポジウム－, 2013年11月, 日本語300MPa級冷間圧延鋼鈑SPCCを母材とする十字引張型摩擦撹拌点継手の一定および変動荷重下における疲労特性
口頭発表（一般）
- 日本機械学会関西支部, 第97期定時総会講演会, 2022年03月パルス加熱後の時系列温度変動分布解析による接着部材の非破壊検査
- 日本機械学会関西支部, 第97期定時総会講演会, 2022年03月テラヘルツ電磁波計測によるプラント設備の維持保全技術の開発
- 日本機械学会関西支部, 第97期定時総会講演会, 2022年03月アクティブ温度ギャップ法を用いた鉄道台車枠のき裂検出
- 日本機械学会関西支部, 第97期定時総会講演会, 2022年03月SLAMを援用した赤外線カメラによる温度分布画像の精度改善
- 日本機械学会関西支部, 第97期定時総会講演会, 2022年03月鋼構造溶接部の熱弾性応力計測の高度化とこれによるき裂進展性評価
- 日本機械学会関西学生会, 2021年度卒業研究発表講演会, 2022年03月パルス加熱後の時系列温度変動計測に基づく接着剤接合領域の検出
- 日本機械学会関西学生会, 2021年度卒業研究発表講演会, 2022年03月散逸エネルギ計測に基づいたSCM435の疲労強度評価
- 日本機械学会関西学生会, 2021年度卒業研究発表講演会, 2022年03月散逸エネルギ計測に基づいた摩擦撹拌接合材の疲労強度評価
- 日本機械学会関西学生会, 2021年度学生員卒業研究発表講演会, 2022年03月赤外線サーモグラフィを用いた鉄道台車枠の疲労き裂検出
- 日本機械学会関西学生会, 2021年度学生員卒業研究発表講演会, 2022年03月赤外線計測による防食塗装の劣化評価法の開発
- 日本機械学会関西学生会, 2021年度学生員卒業研究発表講演会, 2022年03月テラヘルツ電磁波計測を用いた石油タンク底部の防食コーティング塗膜の劣化評価
- 日本機械学会関西学生会, 2021年度学生員卒業研究発表講演会, 2022年03月赤外線計測によって得られたガス雲濃度に基づいた漏洩源推定
- 日本機械学会関西学生会, 2021年度学生員卒業研究発表講演会, 2022年03月テラヘルツTDS計測による樹脂材料の引張負荷時の非破壊構造評価
- 日本機械学会関西学生会, 2021年度学生員卒業研究発表講演会, 2022年03月Al合金を母材とした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
- 日本機械学会関西学生会, 2021年度卒業研究発表講演会熱弾性応力測定結果に基づく応力拡大係数評価
所属学協会
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 若手研究, 若手研究, 神戸大学, 2021年04月01日 - 2024年03月31日散逸エネルギ・ひずみ場ハイブリッド計測による異材摩擦攪拌接合の損傷メカニズム解明
- 日本学術振興会, 科学研究費助成事業 基盤研究(B), 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
- 日本学術振興会, 科学研究費助成事業 基盤研究(B), 基盤研究(B), 神戸大学, 2018年04月01日 - 2021年03月31日ハイパースペクトル電磁波計測に基づく鋼構造のライフサイクル維持管理スキームの構築
インフラ鋼構造物の供用を停止することなく，効率的，多角的かつ高精度に構造物の劣化事象を検出・評価し，構造物の健全性を保証する非破壊評価法は，国内外を問わず，実用に供するレベルのものは未だ開発されていない．本研究課題では，鋼構造物の２大劣化事象である，「疲労」と「腐食」に対する予知保全に主眼を置き，鋼構造物のライフサイクルを通じての構造健全性トリアージを深化・発展させるために必要な，革新的計測技術ならびに構造健全性評価技術を開発するための学術基盤の構築を目的とする．このため，可視域，赤外域からテラヘルツ領域に至るハイパースペクトル電磁波イメージング計測法を開発し，これまで実現不可能であった，鋼構造物の早期予知保全に関わる疲労損傷および腐食の影響因子の高感度かつ高精度評価を可能とすることで，革新的な構造物の維持管理スキームを構築する． 平成３０年度においては，ハイパースペクトル電磁波イメージング計測法の開発と，これによるハイパースペクトル計測データに基づく疲労，腐食に関する構造健全性評価に基づく革新的構造物維持管理スキームを構築するための基礎検討を，様々な構造物，劣化損傷事象に対して行った．空間，時系列，分光ハイパースペクトルデータを同期計測できる計測法を開発するための基礎検討を行うとともに，様々な劣化事象に対して各波長帯域での電磁波計測を行い，計測データを解析することで疲労，腐食の早期検出の可能性を検討した．