文摘
Based on the crack propagation mechanism of elastic-plastic fracture, a finite element analysis was performed upon the effect of compressive loading on fatigue crack tip stress field in LY12M aluminum alloy. By the validation of test data, two actual engineering models and a published double-parameter crack growth model, called Zhang-model, are all suitable in the case of negative stress ratio, and are used to describe the test data in the corresponding coordinate system. By comparing the degrees of linear correlation, R2, of each fitting line, it shows that Zhang-model is a better engineering method for life prediction of fatigue crack growth under negative stress ratio of aluminum alloy, some factors can be obtained from elastic-plastic finite element computation, and it will save a lot of funds in the new materials research.