On the numerical simulation of fatigue driven delamination with interface elements

Abstract

This paper investigates robustness and efficiency of a method for the numerical simulation of fatigue driven delamination growth in laminated composites. The method is based on the fatigue degradation of a bilinear interface element and the paper studies the dependence of the predicted behaviour on the interface element size, $\Delta$l, and the number of cycles per increment, $\Delta$N. It is concluded that the value of $\Delta$N must be small enough to ensure that at least two increments are required to advance the crack by $\Delta$l. It is also shown that $\Delta$l must be sufficiently small so that at least two interface elements lie in the cohesive zone ahead of the crack tip. The paper also proposes extensions of the model to include a non-zero minimum cyclic load value and an improved algorithm for mixed-mode fatigue driven delamination growth.