基于FIP的焊趾短裂纹行为仿真

短裂纹的成核与早期扩展是疲劳裂纹演变过程的重要组成部分，对疲劳裂纹的演变行为和寿命预测具有重要意义. 针对焊趾局部的微观结构短裂纹，以微观敏感的疲劳指标参量为主要驱动力，基于泰森多边形方法构建了焊趾区域的晶粒模型，模拟了微观结构短裂纹的早期演变过程. 通过与试验结果对比，证实了微观敏感的疲劳指标参量及其计算模型的合理性和有效性. 仿真结果表明，疲劳寿命同时受晶粒所在位置、晶粒尺寸和晶粒取向等因素的影响，晶粒取向的随机性对裂纹宏观尺寸的分散性具有重要作用.

FIP based simulation of short crack behavior at weld toe

The nucleation and early growth stage of short crack are important parts of the evolution process and has significant influences on its evolution behavior and life prediction. For microstructural short cracks at the weld toes, taking the microstructure-sensitive fatigue index parameter as the main driving force, the grain model of the weld toe area was built based on the Voronoi method and the early evolution process of the microstructure short crack was simulated. By comparing with the fatigue test results, the rationality and validity of the microstructure -sensitive fatigue index parameter and its calculation models were confirmed. The simulation results showed that the fatigue life was affected by grain locations, grain sizes and grain orientations at the same time. The randomness of grain orientations played an important role in the dispersion of the macroscopic crack depth.