A dynamic Monte Carlo microscopic damage model incorporating thermo-mechanical coupling in a unidirectional composite

Abstract

On the basis of the study for the heat generation mechanism in unidirectional composites under tensile impact and the interaction between the temperature and the mechanical behaviour of the composite and its constituents, a dynamic Monte Carlo microscopic damage constitutive model taking thermo-mechanics coupling into account is proposed. The foundation of the model is the dynamic Monte Carlo microscopic numerical constitutive damage model for unidirectional composites. The key of the model is to calculate the coupling effect through a statistical average interation method. In this way one can simulate the composite deformation, damage and failure process, and predict its stress/strain curve. The numerical results (stress/strain curves) for unidirectional GRP provide good correlation with experiment results at a strain rate of 300 s −1, based on the bimodal Weibull distribution model of fiber strength. This suggests that the model and the method are rational and effective. Further study shows that the non-linearity of the dynamic stress/strain curve of the composite and its toughness at high strain rates are mainly induced by the cumulative breakage of fibers and its rate and temperature dependence, and thermo-mechanical coupling. Inertia has some effect on the non-linearity of the stress/strain curve and the high-velocity toughness of the composites. The study also shows that the simulations should be carried out on the bimodal Weibull distribution model of the fibers strength. However, there exist a certain deviation between the simulation results and the experiment results when the strain rate is above 800 s −1, and the strain is more than 4%, and further investigation is necessary.