Comparison Between Discontinuous Galerkin Method and Cohesive Element Method: On the Convergence and Dynamic Wave Propagation Issue

Abstract

The zero-thickness cohesive element method (CEM) is a powerful way to simulate crack propagation. However, it suffers from artificial compliance issue and alters the wave speed in dynamic analyses. In this article, we show that the CEM formulation can be correlated to the Babuška and Zlámal, discontinuous Galerkin formulation, and switching to symmetric interior penalty Galerkin (SIPG) formulation improves the accuracy of wave speed approximation. Moreover, we demonstrate the SIPG formulation can better control the nodal jumps between element interfaces with a lower cost than CEM. A convergence study is carried out to support this SIPG robustness.