Fatigue life simulation of the impacted carbon/epoxy composite laminates

The increasing use of composite materials in the aviation industry has led to a greater need to maintain composite structures’ safety against impact damage, especially when exposed to repetitive loading. Since experimental work can be challenging, proposing a simple and practical method of co-simulating composite laminates’ impact and fatigue behavior is crucial. This research presents composite and cohesive fatigue models based on the fundamental models of Shokrieh-Lessard and Turon. Additionally, two impact models with parameters consistent with these fatigue models are presented as well. Then, the impacted composite laminates are analyzed using a VUMAT that includes these models, and the results are compared to experimental data. The numerical analysis shows that the propagation patterns and shapes of different damage modes for impact and tension–tension fatigue are similar to experimental observations. However, for tension–compression, the simulation results differ partially from the tests. The tensile fatigue results showed that the impact had no significant effect on the specimen’s life. In contrast, a 2.1 J impact reduces specimens’ fatigue life for a maximum load of more than 40 % of the compressive strength, under tension–compression fatigue.