한국정밀공학회:학술대회논문집 (Proceedings of the Korean Society of Precision Engineering Conference)
- 한국정밀공학회 1996년도 추계학술대회 논문집
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- Pages.928-932
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- 1996
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- 2005-8446(pISSN)
단일 과대 하중에 의한 균열 성장 지연 거동 예측
Prediction of Crack Growth Retardation Behavior by Single Overload
초록
Single overload fatigue tests with overload sizes ranging from 50% and 100% have been performed to investing ate the fatigue crack growth retardation behavior. A modified and experimental method of Willenborg's model for prediction of crack growth retardation behavior has been developed, based on evaluations of equivalent plastic zone size (EPZS) changing its size along the overload plastic zone boundary. The minimum crack growth rates of each overload size are linearly decreased with overload size increasing, but fatigue lives extended by single overload are increasing much more unlike the crack growth rates. Comparisons of crack growth behavior predicted by EPZS model and Willenborg model have shown that the EPZS model accounts for overload effects better than Willenborg model. These effects include delayed retardation, large retardation region, minimum crack growth rate, and the increase rate of crack growth rate in the region crack growth rate recovered.
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