关键词: 标准扩展有限元法, ABAQUS平台, 三点弯曲梁试验, 不良裂缝构型, 离散弗雷歇距离

Abstract: In practical applications， the analysis of crack problems by the extended finite element method(XFEM) has the problems of highly ill-conditioned overall stiffness matrix， singularity of matrix， etc. The numerical simulation does not achieve the ideal requirement that the analysis result has nothing to do with meshing. The three-point bending beam test was selected based on the ABAQUS platform， and the discrete Freschet distance was introduced to evaluate the difference in crack development path with time history. The influence of the poor crack configuration related to meshing on the simulation results in the application of the standard XFEM was analyzed. The results show that the initial crack endpoint must be at the element boundary during numerical simulation to avoid weakening the components， and poor crack configuration will cause the distortion of the crack development path simulation， and the distortion will increase as the poor coefficient decreases. The poor coefficient u should be controlled within 0.25~1. The convergence and path accuracy can be improved by introducing viscous damping.

Key words: standard extended finite element method, ABAQUS platform, three-point bending beam test, poor crack configuration, discrete Freschet distance