101 - THE COHESIVE – SEQUENTIAL STATIC FATIGUE ALGORITHM: A NOVEL APPROACH FOR THE FATIGUE PROPAGATION OF DELAMINATION IN COMPOSITES (CompTest 2025)
One of the most dangerous and common forms of damage in laminated composites is delamination propagation under fatigue loads. Predicting the evolution of delamination defects under fatigue loads is thus of critical importance. The most common modelling techniques used for this purpose are the Virtual Crack Closure Technique (VCCT) and the Cohesive Zone Modelling (CZM) [1]. VCCT, based on linear elastic fracture mechanics, effectively predicts the strain energy release rate G at a crack tip. However, VCCT has notable limitations, including the need for a pre-existing crack, its inability to account for nonlinear behaviours; moreover, its implementation for fatigue analyses is not straightforward nor very efficient. In contrast, CZM can simulate both crack initiation and propagation while being less sensitive to mesh size, enhancing its accuracy. Despite its advantages, CZM often requires specific implementation strategies for fatigue analyses. Most implementations in the literature rely on custom Abaqus subroutines, such as user material (UMAT) [2] or user element (UEL) [3], to model delamination propagation. This is often a cumbersome task, often requiring very specific expertise and additional modelling assumptions.
Date
21.05.2025.
Keywords
Delamination; Fatigue; Cohesive Zone Modelling; Virtual Crack Closure Technique; Sequential Static Fatigue
