Dynamic crack face contact and propagation simulation based on the scaled boundary finite element method

Abstract

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.