Numerical simulation of the effect of loading history and crack closure on crack propagation behaviour

摘要: Three kinds of finite element models were used to study the fatigue crack growth behavior of 16MnR steel under different stress ratios. The stationary crack propagation model considers only the effect of a crack closure, and the fake dynamic crack propagation model considers only the effect of loading history. However, the loading history and crack closure were considered in the dynamic crack propagation model. Based on the outputted elastic-plastic stress-strain results from the FE analysis, the crack closure process, the stress-strain hysteresis loop, the fatigue damage distribution and the fatigue crack growth rate were studied. The interactive mechanism between the crack closure and loading history for the fatigue crack growth behavior was discussed further. For an identical finite element model, it is difficult to find the appearance of a crack closure for the loading condition with a higher stress ratio. On the other …