Three-dimensional analytical model for composite laminate with transverse cracks by assuming parabolic crack opening

In this study, a model for the three-dimensional effective compliance of composite laminates with transverse cracks is developed based on continuum damage mechanics. Three-dimensional laminate theory is used to reproduce all the thermoelastic properties of the damaged laminate. The damage variable, which describes the degree of stiffness reduction caused by transverse cracking, is formulated based on a three-dimensional micromechanical model, with a loose boundary condition and assuming parabolic crack opening. These assumptions contribute to the analytical accuracy of the stiffness reduction model, while simplifying the damage variable expression. The effective thermomechanical properties of various composite laminates are predicted using the proposed model and compared with finite element analysis (FEA) and experimental results. We found that the proposed model with derived damage variable successfully reproduces the FEA and experimental results of stiffness degradation of damaged composite laminates.