Mechanism of fatigue damage of materials under six-axial random vibration and evaluation testing method

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K14556
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Materials/Mechanics of materials
• Research Institution: Okayama University (2018-2019); Yokohama National University (2017)
• Principal Investigator: Sakamoto Junji 岡山大学, 自然科学研究科, 助教 (50752052)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 疲労損傷 / 多軸ランダム振動 / 非比例負荷 / 共振

Outline of Final Research Achievements

We investigated a fatigue fracture of a material subjected to multi-axis random vibration which complicatedly changes the amplitude and direction. In the case of a material with a simple shape, the material could vibrate in a resonance mode. Therefore, there is a possibility that the fatigue strength can be evaluated using the stress in the direction with the largest load. In the case of a material with a complicated shape, the material could vibrate in a few resonance modes. Therefore, there is a possibility that the fatigue strength cannot be evaluated using only the stress in the direction of the largest load. The evaluated fatigue strength might be higher than the actual fatigue strength.

Free Research Field

材料力学

Academic Significance and Societal Importance of the Research Achievements

自動車や航空機をはじめとする輸送機器等の機械・電子機器は、使用時に大きさや方向が複雑に変化する多軸ランダム振動を受ける場合が多い。そこで本研究では、多軸ランダム振動を受ける材料の疲労損傷メカニズム解明および評価試験法の構築を目的として、実験による検討を行った。その結果、多軸ランダム振動時の材料の疲労損傷に関して、知見を得た。本成果は、機械・電子機器等の長期信頼性の確保かつ無駄のない最適な強度設計に貢献できると期待される。