A novel implementation of the cohesive zone model for the fatigue propagation of delamination in composites using a sequential static fatigue algorithm

Composite materials are particularly exposed to delamination under fatigue loading conditions, which can significantly compromise their structural integrity. The ability to accurately and efficiently estimate the progression of delamination under fatigue is crucial for enhancing the safety and reliability of lightweight composite structures. The aim of this paper is to implement the cohesive elements formulation in a Sequential Static Fatigue (SSF) algorithm named C-SSF. The C-SSF algorithm simulates delamination propagation under fatigue loading by conducting a series of sequential static simulations. The accuracy of the C-SSF method is validated by comparing its results with experimental data from two published case studies. The results demonstrate that this approach can effectively simulate delamination growth under fatigue loading. Compared to a similar approach based on the Virtual Crack Closure Technique (VCCT), the C-SSF algorithm provided superior accuracy, especially when large and curved delamination fronts were involved. The C-SSF method proved its capability to simulate propagation of delamination in composite structures, making it a valuable tool for modelling the fatigue behaviour of other similar structures.