In a previous blog I showed how to model a stationary crack and calculate the J-integral to determine whether the crack propagates. Abaqus offers different techniques to simulate crack propagation, including surface- and element-based cohesive behaviour and the virtual crack closure technique. When using one of these methods with conventional FEM, the location of the crack needs to be prescribed beforehand. When the eXtended Finite Element Method (XFEM) is used, this is not necessary. In this case, enrichment terms are added to the normal displacement interpolation, so a crack within an element can be described. In this blog I will explain how to model crack propagation using the surface-based cohesive behaviour approach and XFEM.