Finite-element modeling of heat transfer in carbon/carbon composites

A finite-element model has been developed to predict the thermal conductivi ties, parallel and transverse to the fiber axis, of unidirectional carbon/c arbon composites. This versatile model incorporates fiber morphology, matri x morphology, fiber/matrix bonding, and random distribution of fibers, poro sity, and cracks. The model first examines the effects of the preceding var iables on the thermal conductivity at the microscopic level and then utiliz es those results to determine the overall thermal conductivity. The model w as able accurately to predict the average thermal conductivity of standard pitch-based carbon/carbon composites. The model was also used to study the effect of different composite architectures on the bulk thermal conductivit y. The effects of fiber morphology, fiber/matrix interface, and the ratio o f transverse fiber conductivity to matrix conductivity on the overall compo site conductivity was examined. Published by Elsevier Science Ltd.