Fatigue Failure Prediction for Fiber-Axial Compressive Cyclic Loading in CFRP Based on an Entropy Damage Criterion and Micro-Buckling Model

This study presents a framework for estimating the longitudinal compression–compression fatigue life of unidirectional carbon-fiber-reinforced polymer (UD-CFRP) by linking entropy-based matrix degradation to a fiber micro-buckling criterion. A reference effective fiber-direction shear modulus of 2000 MPa was selected using published shear responses of carbon/epoxy composites. Its degradation was prescribed phenomenologically using <!-- MathType@Translator@5@5@MathML2 (no namespace).tdl@MathML 2.0 (no namespace)@ -->