2-D boundary element simulation of fatigue crack growth on engineering structure

摘要

Now it is common that engineering structures are rupture collapse due to the propagation of initial mini-cracks.According to the fracture mechanics a boundary element model of gear ring was constructed for calculating by boundary elements method in this paper.Stress intensity factor was calculated by the displacement interpolation formula; meanwhile crack propagation direction was predicted by the greatest tangential tensile stress rule through Fortran program.As the crack propagated,the mesh was automatic regenerated.The influence of different rim size to the fracture of gear ring under the same initial crack and loads was analyzed during the simulation course.The result of stress intensity factor calculating by ANSYS was compared with that by boundary element method.The calculating results show that the method has small work load and high degree of accuracy.%目前工程结构中由于裂纹的疲劳扩展而导致断裂破坏的现象非常普遍.从断裂力学角度,建立一齿圈的边界元模型进行计算.通过编制Fortran程序,用位移插值公式计算应力强度因子,同时用最大周向应力法则判断裂纹扩展方向.当裂纹扩展后,计算网格能自动重新划分.在模拟过程中,分析了在相同的初始裂纹和载荷下不同轮缘尺寸对齿圈断裂的影响.并把边界元与ANSYS计算的应力强度因子进行了比较.计算结果表明,这种方法工作量小,准确度比较高.