This paper extends the static contact problem of crack faces to include dynamic contact and crack propagation based on the relevant literature (Zhang et al., 2018). The scaled boundary finite element method is used to solve dynamic crack face contact and crack propagation problems. Based on the scaled boundary finite element shape function considering side-face loads, the system dynamic equilibrium equation and related characteristic matrix are presented. The Lagrange multiplier method is used to establish the contact model between the crack faces. The meshing and remeshing algorithm is carried out by using arbitrary polygonal meshes. When a crack propagates, the remeshing operation involves only a small region of polygons around the propagating crack tip. Mesh mapping technology is used to transfer the response parameters to newly generated nodes. The proposed method is validated by analysing the impact of two identical bars and the dynamic contact of crack faces in the Koyna Dam. The results show that the dynamic contact model can effectively simulate the opening and closing of crack faces, and the longer the crack is, the greater the influence of the non-linearity of the contact along a crack face on the dynamic stress intensity factor and dynamic response. Finally, a dynamic crack propagation problem is simulated. Compared with the dynamic crack response without considering the contact constraint, when considering the contact constraint, the crack initiation angle is closer to the corresponding theoretical solution, and the crack propagation path is closer to the corresponding experimental result. Thus, the dynamic contact constraint condition of crack faces has an important influence on crack propagation.

本文根据相关文献（Zhang et al., 2018）将裂纹面的静态接触问题扩展为包括动态接触和裂纹扩展。缩放边界有限元方法用于解决动态裂纹面接触和裂纹扩展问题。基于考虑侧面载荷的缩放边界有限元形状函数，给出了系统动态平衡方程和相关特征矩阵。采用拉格朗日乘子法建立裂纹面之间的接触模型。网格划分和重新网格划分算法是通过使用任意多边形网格来执行的。当裂纹扩展时，重新网格化操作仅涉及裂纹周围的一小部分多边形区域。扩展裂纹尖端。网格映射技术用于将响应参数传递给新生成的节点。通过分析 Koyna 大坝中两个相同钢筋的影响和裂缝面的动态接触，验证了所提出的方法。结果表明，动态接触模型能够有效地模拟裂纹面的张合，裂纹越长，沿裂纹面接触的非线性对动态应力强度因子和动态应力的影响越大。回复。最后，动态裂纹扩展问题是模拟的。与不考虑接触约束的动态裂纹响应相比，考虑接触约束时，裂纹萌生角更接近对应的理论解，裂纹扩展路径更接近对应的实验结果。因此，裂纹面的动态接触约束条件对裂纹扩展有重要影响。