A new method for modelling cohesive cracks using finite elements

A model which allows the introduction of displacements jumps to conventional nite elements is developed. The path of the discontinuity is completely independent of the mesh structure. Unlike so-called `embedded discontinuityʹ models, which are based on incompatible strain modes, there is no restriction on the type of underlying solid nite element that can be used and displacement jumps are continuous across element boundaries. Using nite element shape functions as partitions of unity, the displacement jump across a crack is represented by extra degrees of freedom at existing nodes. To model fracture in quasi-brittle heterogeneous materials, a cohesive crack model is used. Numerical simulations illustrate the ability of the method to objectively simulate fracture with unstructured meshes