Level set propagation for mixed-mode crack advance

In the extended finite element method framework, the advantage of being able to represent cracks independently from mesh rests on the use of level sets. Propagation simulation is connected to the update of these level sets, following the resolution of differential equations of evolution. In this document, we analyse these equations so that fast and robust mixed-mode propagation methods can be put forward. The proposed methodology can also manage the separation of a crack front into several fronts as well as the merging of several fronts during the propagation process. An example of 3D non-planar propagation is proposed at the end to show the efficiency of our choices.