Continuum damage mechanics model of glass/epoxy composite laminate under in-plane shear loading

In order to investigate the in-plane shear behaviour of S2-glass/epoxy composite laminate, continum damage mechanics (CDM) model involving elasticity and plasticity for S2-glass/epoxy laminate under in-plane shear loading was studied in this paper. Typical in-plane tensile shear tests of the composite were conducted, two types of CDM models were established based on the plane stress assumption and the parameters were identified. The former CDM model considered no plasticity while the later one did. Both two CDM models were coded to VUMAT through ABAQUS/Explicit, finite element analysis (FEA) for in-plane shear behaviour of the composite was conducted by them following experimental tests. The results of FEA were compared with experiments and the influence of plasticity on the in-plane shear behaviour of the composite was discussed. Element types on the results of FEA were also analyzed. The results show that the CDM model considering no plasticity can exactly predict the failure strength of S2-glass/epoxy composite under in-plane shear loading, but it can not well predict the nonlinear mechanical behaviour. However, when coupled with isotropic plasticity criteria, the CDM model can perfectly predict the nonlinear mechanical behavior, and the result of failure strength is also acceptable compared with the experimental results. The CDM models can also be used for FEA simulation by shell elements, but the results of load-deflection curve are a little lower than that using plane stress elements because of the transverse shear behaviour of shell elements. Moreover, reduced integration method is found to be beneficial for FEA simulation.