A Multiscale Approach for Fiber Damage Prediction of Composite Open-Hole Tension Coupon under Fatigue Loading

Abstract

Since fiber-reinforced polymer (FRP) composites are inherently anisotropic and display a wide variety of failure mechanisms, predicting their fatigue behavior is a challenging task. Prediction of fatigue in FRP composites demands progressive damage analysis tools that account for constituent physics of the problem. In this work a fatigue failure methodology based on the kinetic theory of fracture (KTF) is developed that uses the physics of the matrix constituent to track damage in both laminar and inter-laminar regions. Fiber failure is predicted using the maximum principal stress theory. Matrix and fiber damage mechanisms are implemented together to predict the overall progressive fatigue behavior of the composite. Using this methodology, finite element simulations of an open-hole coupon subjected to tension-tension fatigue loading were conducted. The resultant residual stiffness and the damage location, type and amount inside the plies with number of fatigue cycles were benchmarked against published experimental data.