Examining the effect of the shear coefficient on the prediction of progressive failure of fiber-reinforced composites

The ultimate damage of composites under tension usually results from fiber damage, which includes both tensile and shear contributions. In this study, the shear coefficient alpha of the fiber yarn is incorporated into the failure criterion to consider the shear effect of the fiber yarn. An analytical model is then proposed that combines a homogenization method and the enhanced failure criterion to facilitate quick evaluation of the progressive damage and failure of the composite. The sensitivity of alpha on the behaviors of progressive damage and failure are comprehensively explored for different types of fiber-reinforced composites, including a laminate, a plain weave composite, a two-dimensional triaxially braided composite, and a three-dimensional woven composite. The results indicate that damage and failure behaviors are generally sensitive to the shear coefficient, and composites with more complex textile structure demonstrates greater sensitivity to the alpha. An analysis of the sensitivity of alpha for different failure criteria was also conducted, and the results reveal that the Hashin-Hou criterion shows more sensitivity to alpha than the Chang-Chang criterion, the Hoffman criterion, or the Tsai-Wu criterion. Therefore, the identification of the shear coefficient is significant for exploring the damage and failure behaviors of fiber- reinforced composites.