Simulation of Crack Propagation and Failure in Thin Walled Structures using the Cohesive Model
The cohesive model is a two-parameter model for damage and crack propagation in materials. It has been used since the 70s for brittle materials and since the late 80s for metals, but up to now the applications are limited to structures, which can be modelled using 2D plane strain or 3D finite element analyses. It is shown here that the model can be used for thin walled structures as well, which are in general meshed by shell elements. Special aspects, which will be discussed, are the failure modes occurring in shells and the prediction of the crack propagation direction in complex shell structures. As an example a stiffened vessel under internal pressure is investigated and crack initiation, maximum load and the propagation direction will be determined.