Evaluation of transverse thermal diffusivity of unidirectional fiber-reinforced composites

Abstract

The applicability of the homogeneous medium approximation to transverse transient heat conduction in unidirectional fiber-reinforced composites is examined. The study focuses on the problem of transient heat conduction in thin cross-sections, encountered in applications such as the manufacture of commercial prepreg tapes, the filament winding process, etc. The flash experiment for measuring the apparent transient diffusivity was numerically simulated for a wide range of composite parameters. Based on the parametric studies, a critical sample thickness is proposed, above which the composite may be analyzed in a simplified manner as a homogeneous medium having an equivalent transient thermal diffusivity. Below the critical thickness, the homogeneous medium approximation may introduce nonnegligible errors. An analytical means for the evaluation of the homogenized transient diffusivity in practical situations is also presented.