Growth Rate And Closure Of Fatigue Cracks Under High-cycle Fatigue Random Loading
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M. Miyake, Y. Kurosima & S. Harada
Growth rate and closure of fatigue cracks under high-cycle fatigue random loading M. Miyake, Y. Kurosima, S. Harada Department of Mechanical Engineering, Kyushu Institute of Technology, 1-1 Sensuicho, Tobata-ku, Kitakyushu 804, Japan ABSTRACT This paper deals with evaluating fracture mechanics parameter suitable for the description of crack growth rate under high-cycle fatigue (HCF)random loading. In this respect, the fracture mechanics parameters AKeff and ACTOD were applied to characterize the fatigue crack growth rate da/dN under random loading as well as asymptotically increasing or decreasing loading. The results showed that ACTOD versus da/dN relationship can be well correlated with the AKeff versus da/dN relationship under each loading condition. In addition,the parameter ACTOD is better than AKeff in predicting fatigue life. In case of low-cycle fatigue(LCF) random loading, CTOD was a suitable parameter to understand the crack growth rate as well as plastic strain.