Interaction between kinking and splitting in the compressive failure of unidirectional fiber reinforced laminated composites

The interaction between fiber kink banding and splitting in the compressive response of fiber composites is investigated by adopting a micromechanics based 2D finite element representation of the composite. The effect of scaling of the computational model (size of model) on the compressive strength and post critical response is also studied. The size of the computational model is scaled in a systematic manner by increasing the number of fibers in the model, but maintaining a fixed aspect ratio and fiber volume fraction. The response of the model changes with change in model size, and therefore, a converged model size (baseline) for predicting compressive strength is first established. Since the strains experienced within the kink band are very large, the baseline model is extended to account for splitting as a potential mode of failure by adopting a discrete cohesive zone model. A parametric study is carried out to investigate the interaction between kinking and splitting in limiting the compressive strength of the composite.