Nonlocal thermo-elastic constitutive relation of fibre-reinforced composites

The effective properties of composite materials have been predicted by various micromechanical schemes. For composite materials of constituents which are described by the classical governing equations of the local form, the conventional micromechanical schemes usually give effective properties of the local form. However, it is recognized that under general loading conditions, spatiotemporal nonlocal constitutive equations may better depict the macroscopic behavior of these materials. In this paper, we derive the thermo-elastic dynamic effective governing equations of a fibre-reinforced composite in a coupled spatiotemporal integral form. These coupled equations reduce to the spatial nonlocal peridynamic formulation when the microstructural inertial effects are neglected. For static deformation and steady-state heat conduction, we show that the integral formulation is superior at capturing the variations of the average displacement and temperature in regions of high gradients than the conventional micromechanical schemes. The approach can be applied to analogous multi-field coupled problems of composites.