Fracture-fatigue damage prediction in CFRP laminates: A multi-scale thermo-mechanical approach

Carbon epoxy composites offer low weight and excellent mechanical strength, however, under cyclic thermo-mechanical loads, their performance may degrade. This paper proposed a multi-scale computational approach to predict fracture-fatigue damage accumulation in carbon fibre reinforced polymer composites (CFRPC) laminated at elevated temperatures (below glass transition temperature of polymer matrix). Mori-Tanaka homogenization method is used to determine effective thermo-mechanical properties of laminates at mesoscale. These properties are employed in macroscale simulations incorporating different failure criteria (Tsai-Wu, Hoffman, and Rotem) for laminates with varying fibre percentages (45%, 53%, and 59%). The proposed model predicts tension-compression fatigue and correlates well with experimentally obtained fatigue life data. A custom script developed in COMSOL implements the failure models and damage accumulation to estimate fatigue life. By using scanning electron microscopy, post-failure analysis reveals typical damage mechanisms in laminates. This study provides a reliable multi-scale framework for predicting fatigue and damage evolution in composites under cyclic thermo-mechanical loading, providing valuable insights for aerospace applications.