HIGH-CYCLE FATIGUE MODELLING ON A BENCHMARK DCB MODE I DEBOND USING A COHESIVE ZONE MODEL

A benchmark study on high-cycle fatigue modelling using a cohesive zone model presented for a bonded composite double-cantilever beam (DCB) joint. A user-developed subroutine, USDFLD, was applied to make the field variable represented by a characterized damage parameter for controlling the degradation and failure behaviour of cohesive elements. Accumulative local cohesive fatigue damage was analyzed via a correlation with global crack growth rate characteristic. The damage assessment was accomplished according to theories on fracture mechanics, damage mechanics, fatigue characteristics, and cohesive zone modelling through cycle jump approach. Debond length variation through fatigue cycles was determined using an analytical solution. Also, an available Abaqus fatigue approach integrated with virtual crack closure technique (VCCT) was conducted under two extreme loading ratios. Good agreement was obtained between the test and modelling results. Results discussion and recommended appropriate increment size for the proposed high-cycle fatigue modelling methodology are presented.