Simulation of tensile fatigue crack propagation in carbon fiber unidirectional laminates under progressive fatigue damage model

Abstract

Abstract This paper predicts and analyzes the tensile fatigue crack propagation of carbon fiber reinforced unidirectional laminates at high-stress levels using the carbon fiber stiffness strength degradation formula. The results show that different paving modes significantly affect crack propagation and stress distribution. Under the 45° layup, two cracks appeared. The upper crack expanded along the fiber direction, and the lower crack first appeared as a horizontal crack at the constrained end and then along the fiber direction. Under 0° layering, vertical cracks appear at the prefabricated crack tip, and the crack direction is the same as the loading direction. At a -45° layup, two cracks appeared at the prefabricated crack tip, and then the lower crack extended to the integral separation of the test piece. In addition, the strain characteristic analysis shows that the strain increases and decreases rapidly during crack propagation. This study has a certain reference value for further understanding of fatigue crack propagation characteristics of carbon fiber-reinforced composites.