A new way is proposed to simulate the crack propagation paths of the multi-cracked structure. Firstly, the complete displacement and stress fields of the multi-cracked structure are calculated by the extended boundary element method (XBEM) coupled with characteristic analysis of the crack tip. Secondly, based on the maximum circumferential stress criterion by considering the contribution of the non-singular stress terms, the crack initiation angles are obtained. Thirdly, the cracks propagate forward along the crack initiation angles to form a new multi-cracked structure. During this process, boundary element adaptive mesh technique is established and the XBEM is used to analyze the newly formed multi-cracked structure repeatedly. Finally, the crack propagation paths of the multi-cracked structure are obtained. Numerical examples show that the results obtained by the XBEM are in good agreement with the experimental results.

提出了一种模拟多裂纹结构裂纹扩展路径的新方法。首先，采用扩展边界元法（XBEM）结合裂纹尖端特征分析，计算出多裂纹结构的完整位移场和应力场。其次，基于最大周向应力准则，考虑非奇异应力项的贡献，得到裂纹萌生角。第三，裂纹沿裂纹萌生角向前扩展，形成新的多裂纹结构。在此过程中，建立边界元自适应网格技术，并利用XBEM对新形成的多裂纹结构进行反复分析。最终得到多裂纹结构的裂纹扩展路径。