Abstract
The effective thermal diffusivity of unidirectional fiber composites, of which effective thermal conductivity under the steady heat flow condition have been already investigated systematically, under the unsteady transverse and parallel directional heat flow condition were determined by a finite element method. The relation between the effective thermal conductivity and the apparent thermal conductivity of the composites measured by the usual laser flash technique was discussed and the condition that the former agreed with the latter was determined.
