2022 Fiscal Year Final Research Report
Investigation of vibration fatigue crack growth behavior and vibration fatigue strength improvement by peening
| Project/Area Number |
20K14610
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| Research Category |
Grant-in-Aid for Early-Career Scientists
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| Allocation Type | Multi-year Fund |
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| Review Section |
Basic Section 18010:Mechanics of materials and materials-related
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| Research Institution | Okayama University |
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Principal Investigator |
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| Project Period (FY) |
2020-04-01 – 2023-03-31
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| Keywords | 曲げ振動 / 共振 / 疲労 / き裂進展 / 伸び / 固有振動数 / ピーニング / せん断 |
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| Outline of Final Research Achievements |
In this study, the stress field of a specimen subjected to bending vibration at a vibration frequency near the resonance point was examined from calculated strain values derived from the vibration equation and experimental strain values obtained from the specimen with strain gauges. As a result, the strain distribution during bending vibration near the primary resonance point in the undamaged specimen was clarified. The tendency of the load change during vibration can be divided into two patterns depending on the vibration frequency, one in which the load increases gradually and the other in which the load decreases gradually. In the case in which the load increases gradually, the effect of peening on the crack propagation is gradually decreases with the crack growth compared to the other case.
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| Free Research Field |
材料力学
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| Academic Significance and Societal Importance of the Research Achievements |
自動車や航空機に代表される輸送機械のように使用中に振動を受ける機械においては，その振動によって構成する材料や電子機器等に繰返し負荷がかかる．そのような振動によって生じる材料損傷は大事故を招く恐れがある．そのため，振動による材料損傷のメカニズムを明らかにすることが安全性を考慮する上で重要である．本研究では，振動試験システムを作製し，振動時の材料の力学的状態およびき裂進展に着目した実験を行った．その結果，重要な知見を得た．
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