A study on the influence of fatigue damage initiation laws for cohesive zone models in propagation-driven load cases
Abstract
Cohesive zone models for composite laminates considering a Paris-law based damage function for fatigue are well established to model propagation of delamination from existing flaws. However, these models have some limitations in cases without an existing flaw. The limitations occurring in these special cases can be overcome by incorporating SN-curve based damage initiation laws. However, it has not yet been investigated if the combination of different damage models has a strong influence on scenarios with existing pre-cracks, such as typical linear elastic fracture mechanics specimens. Therefore, the 4ENF test is modeled with a propagation-only model and a combined initiation and propagation model. It is shown that the SN-curve based damage initiation model does not affect the Paris-law based damage propagation model negatively.
