Micromechanical modelling and simulation of unidirectional fibre-reinforced composite under shear loading

In this paper, micromechanical modelling and simulation were performed for unidirectional fibre reinforced composites subjected to transverse and in-plane shear by finite element method. Representative volume element consisting of fibre, matrix and interface was established for the simulation, considering random fibre distribution. The two dominant damage mechanisms of fibre reinforced composites, matrix plastic deformation and interfacial debonding were taken into account in the simulation. Periodic boundary conditions were applied to the representative volume elements. The simulation results indicate that the failure behaviour of the composites under transverse shear is dominated by matrix plastic damage, while the in-plane shear damage is initiated by interfacial debonding and then ultimate failure is caused by matrix damage. Fibre distribution is found to have a more significant effect on the failure behaviour of the composites under transverse shear than in-plane shear. The predicted in-plane shear strength and failure strain show reasonable agreement with the experimental results.