Finite-element simulation of interfacial crack propagation: Methods and tools for the complete failure process under large scale yielding

Interface crack propagation is described with an advanced finite element model on the basis of a non-linear material law with large plastic deformation and a global energy release rate criterion. The simulation covers the whole failure process in one model, starting from small loads, development of a large plastic zone, onset of cracking and crack propagation until complete rupture.The model implements an elastic–plastic material law including hardening. Numerical stability and reliability strongly depend on the correct implementation of the material law. The central part is the realization of a moving crack. Due to the discrete nature of a finite element model, the crack can only propagate in finite steps resulting in sudden changes of boundary conditions. Smoothing these changes is essential for numerical stability and reasonable computation time.Simulated crack propagation bases on a criterion to decide between further increase of load or further advance of crack. A global energy release criterion is used here and was found to be independent of the specific discretisation.