Simulation of high-cycle fatigue-driven delamination in composites using a cohesive zone model

摘要

In this PhD thesis several published strategies for the simulation of high-cycle fatigue-driven delamination using cohesive elements are investigated in mode I using an efficient analytical model which eliminates the numerical errors involved in a finite element simulation. A detailed sensitivity study of all the models is performed with respect to the element size and the cycle-jump. The models are then compared and their advantages and disadvantages highlighted. For two of the models improvements are proposed and investigated using the analytical model.udNecessary conditions for a successful fatigue model are then highlighted and a new model is proposed. A sensitivity study demonstrates a very good performance of this model. The new fatigue degradation strategy is implemented into a user defined element (UEL) within the commercial finite element software ABAQUS. Two simulations are then performed for pure mode I and mode II fatigue-driven delamination. The new strategy is shown to achieve good agreement with the input Paris law and is also shown to perform well in comparison with FE implementations of some of the published cohesive element strategies for fatigue-driven growth of delamination.