Progressive damage modelling of bonded composite repairs

Presented is a three-dimensional progressive damage model that can assess the mechanical behaviour of bonded composite repairs of cracked metallic plates. The model is able to assess the stress intensity factor (SIF) at the crack tip, patch debonding and damage accumulation in the composite patch as functions of the applied load. Considered are the stress analysis, failure analysis and material property degradation. Stress analysis is performed using a three-dimensional detailed parametric finite element (FE) model developed using the ANSYS FE code. Failure analysis is performed using a set of stress-based polynomial failure criteria. Material property degradation of the failed material (patch and adhesive) is performed using appropriate degradation rules. The three model components have been programmed in the ANSYS FE code creating a user-friendly parametric macro-routine, which can be easily applied to bonded repairs of different materials and configuration.