Fatigue simulation for damage propagation in composite structures

The capabilities of newly-implemented Abaqus procedures for delamination propagation in composite structures subjected to fatigue loading are investigated by examining the response of double cantilever beam (DCB) tests. Two-dimensional and three-dimensional models are at first evaluated under quasi-static loading conditions using the virtual crack closure technique (VCCT). The results show good agreement between the shapes of the predicted and experimental delamination fronts. Then, fatigue analyses are performed using two fatigue procedures: direct cyclic fatigue (DCF) and simplified fatigue (SF). It is found that, when modeling the response of DCB tests, the SF and DCF procedures correctly recover the Paris law propagation rate. The analysis with the SF procedure appears to require 50 times less computational time than DCF. However, the fatigue delamination front is characterized by sharp edges. Therefore, additional modeling features such as gradual nodal release may be required before the residual lives of more complex postbuckled structures can be predicted with confidence.