A new method for modelling cohesive cracks using finite elements

A model which allows the introduction of displacements jumps to conventiona l finite elements is developed. The path of the discontinuity is completely independent of the mesh structure. Unlike so-called 'embedded discontinuit y' models, which are based on incompatible strain modes, there is no restri ction on the type of underlying solid finite element that can be used and d isplacement jumps are continuous across element boundaries. Using finite el ement shape functions as partitions of unity, the displacement jump across a crack is represented by extra degrees of freedom at existing nodes. To mo del fracture in quasi-brittle heterogeneous materials, a cohesive crack mod el is used. Numerical simulations illustrate the ability of the method to o bjectively simulate fracture with unstructured meshes. Copyright (C) 2001 J ohn Wiley & Sons, Ltd.