Cohesive zone modelling to predict crack growth under fatigue loading

Abstract

Abstract This manuscript presents the partial results in the development of numerical models based on Cohesive Zone Modelling to analyse quasi-static and fatigue crack propagation in adhesive interfaces. This work applied to adhesive interface between fibre laminates and structural epoxy adhesive of a wind turbine blade 3rd shear-web connection to the trailing edge panels. Fracture characterization experiments using the Double Cantilever Beam with Unequal Bending Moments (DCB-UBM) specimen are performed, and results are used to determine different modelling parameters, such as the mixed-mode cohesive laws and fatigue damage parameters for cohesive crack propagation. The developed numerical model is compared and validated against sub-component testing on two different scale levels, using a Modified Tear Test (MTT) specimen geometry with simplified geometry and loading, and a more complex geometry sub-component specimen with a simplified Shear Web Disbond Test (SBDT). The work is carried out as part of the CORTIR-II project, funded by the Danish Ministry of Energy.