Thermal conductivities of three-dimensionally woven fabric composites

This study investigates the effect of three-dimensional fiber reinforcement on the out-of-plane thermal conductivity of composite materials. Composite preforms 3D orthogonally woven with pitch carbon yarns and plied copper wires in thickness direction. After infusion, using a vacuum-assisted resin transfer molding process, the measured out-of-plane thermal conductivities of the resultant composites showed significant increase compared to a typical laminated uniaxially or biaxially reinforced composite. Although the through-thickness thermal conductivity of the samples increased with through-thickness fiber volume fraction, the values did not match those predicted by a simple rule of mixture. Using finite element models to better understand the behavior of the composite material, improvements to an existing analytical model were performed to predict the effective thermal conductivity as a function of the composite material properties and in-contact thermal material properties.