Micromechanical matrix failure analysis for unidirectional fiber-reinforced composites

Abstract The cracking of composite matrix is dangerous for composite overwrapped pressure vessel while used in a cryogenic environment. The mismatch between fiber and matrix deformation under cryogenic condition will lead to non-negligible internal stresses in the composite matrix, which highlights the significance of micromechanical analysis focusing on the microscale failure of composite matrix. In this study, we propose a multiscale strategy to evaluate the failure of unidirectional FRC laminates under a combined loading condition of transverse compression/tension and in-plane shear. The micro-stress fields are obtained by micromechanical modeling and the failure prediction is based on two phenomenological multiscale criteria. Comparing to the bridging model, this multiscale failure criteria has improved prediction accuracy according to previous experimental characterizations. Numerical examples based on this multiscale analysis strategy can catch the shear-strength-enhancement effect and a “compression lag” effect under cryogenic temperature.