Numerical method for estimating fatigue crack initiation size using elastic-plastic fracture mechanics method

摘要

To solve the fatigue crack initiation problem, it is necessary to calculate the fatigue crack initiation size. According to the aspect of macroscopic crack development, the calculation method of crack initiation size is determined by the critical dimension of fatigue crack initiation. Simultaneously, the elastic-plastic fracture mechanics (EPFM) method is used to study short crack fatigue life by considering the cumulative damage rule of crack initiation life, and the calculation model of fatigue crack initiation size caused by symmetric cyclic torsional alternating stress is established under low strain. The crack initiation dimension of component is estimated, which lays a foundation for the study of fatigue life. Then the feasibility of this method is verified by comparing with the crack initiation size, which is determined by predicting the non-propagating crack size (NPCS). (C) 2019 Elsevier Inc. All rights reserved.