光滑试样表面疲劳裂纹演化的数值仿真

考虑裂纹形核，扩展，合并以及晶界的作用等因素，对光滑圆试样表面疲劳裂纹的演化进行了数值模拟。结果表明，疲劳裂纹系统的演化是由无序向有序转化的过程，演化诱致突变。这一过程与实验观察到的结果一致。疲劳裂纹系统的演化终态具有很大的分散性，主要表现为裂纹路径的随机性和突变寿命的分散性。样本的随机性是造成上述分散性的外因，系统对裂纹位形的敏感性是内因。

NUMERICAL SIMULATION ON THE SMOOTH SURFACE'S FATIGUE CRACKS EVOLUTION

There are abundant characteristics of non-linear behavior included in the Fatigue Cracks System(FCS). The numerical simulation of the FCS evolution on the round smooth surface is done considered the elementary processes such as crack initiation, crack propagation, coalescence and the effect of grain boundary. And it's shown that the evolution of the FCS is a transition process from disorder to order, evolution induces catastrophe. The simulation result is agreement with the experimental investigation. The final state of the fatigue cracks evolution is largely scatter that represented as random crack path and life scatter. The random of material sample is the external reason, while the sensitivity to the crack's site and direction is the essential one that result in the scatter above mentioned.