A dynamic Monte-Carlo simulation for unidirectional composites under tensile impact

Abstract

A dynamic Monte-Carlo simulation method, based on a two-dimensional model with fine mesh, sufficient fibers and adequate length, which takes the effect of the inertia and the constitutions of rate dependence into account for the unidirectional composites has been established. On the basis of the dynamic properties of carbon and glass fibers and epoxy resin, the Monte-Carlo simulations are carried out to study the tensile impact failure processes of unidirectional CFRP and GFRP. The simulated stress/strain curves and micro-failure process of the unidirectional CFRP are in good agreement with the experiments. This shows that the simulation method and the program are effective for the tensile impact failure process of the composites made from rate-insensitive fibers having a small failure strain. However, no matter whether we use the single or bimodal Weibull distribution parameters of glass fibers, the simulated results for the unidirectional GFRP are inconsistent with the experiments. This means that the method cannot simulate the tensile impact failure process of composites consisting of rate-sensitive fibers with large failure strain, although the effect of the fibre rate sensitivity (high-speed ductility) and inertia are taken into account. This indicates that some important mechanism exists to induce the high-speed ductility and stress/strain curve non-linearity of the composite other than those of high-speed ductility and cumulative failure of the fiber, and inertia. This process may be thermo-mechanic coupling.