Extended finite element modeling of 3D dynamic crack growth under impact loading

This paper is devoted to the numerical simulation of the dynamic propagation of non-planar 3D cracks under transient loadings. For that purpose, in an explicit finite element code, the X-FEM with only discontinuous enrichment is used coupled with level sets to represent the crack geometry. We show on a complex example that the commonly used Hamilton-Jacobi based level set updating algorithm lacks robustness and numerical efficiency to model such types of problems. To circumvent this, we introduce a simple geometric updating algorithm that does not involve any equation solving, and is therefore numerically cheap. The robustness of this updating algorithm is demonstrated on several virtual propagation examples. Finally common benchmark used in the literature as well as a complex experiment involving the dynamic propagation of a non-planar 3D crack under impact loading are used to demonstrate the efficiency of the approach.