A Novel Robust Remeshing Finite Element Technique for Fracture Propagation

Abstract

In this work, a novel and robust remeshing algorithm for crack opening problems is proposed, combined with triangular plane stress finite elements. In the proposed algorithm, the crack tip efficiently propagates until a pre-established maximum crack length is achieved and the crack propagation direction is defined considering the maximum tangential stress criterion. The stress state at the crack tip is obtained using a weighted average of the stresses of the integration points adjacent to the crack tip, to smoothen the stress field near the crack tip. In order to achieve accurate stress fields in the vicinity of the singularity, the proposed algorithm establishes that there is always a fixed number of nodes and elements surrounding the crack tip. To verify the accuracy of the algorithm, three benchmark tests were analyzed and the solutions were compared with results available in the literature. It was observed that the proposed technique allows to maintain the meshes regular during the propagation process, significantly reducing the number of distorted elements, which solves one of the main problems when simulating crack propagation with the finite element method (FEM). Additionally, the obtained results allowed to understand that this algorithm generally leads to accurate crack paths.