Heat and mass transfers within decomposing carbon fibers/epoxy resin composite materials

摘要

Carbon fibers/epoxy resin composite laminates decompose by pyrolysis and oxidation when submitted to high heat fluxes. A multi-components approach is proposed to describe all transient decompositions of the material from the virgin state to the final charred state. Temperature, bulk density, pressure and species distributions are determined by solving heat and mass conservation laws. The model is based on a porous medium description that includes gas creation and transport within the laminate, driven respectively by Arrhenius' and Darcy's laws. The model accuracy is first evaluated against numerical and experimental results extracted from reference literature surveys. Nevertheless orthotropic heat transfers and effects of decomposition gas transport within the material up to the surface remain often uninvestigated. An experiment is thus carried out to analyze multidimensional heat and mass transfers during the degradation of a widely used CFRP composite exposed to high energy laser beam. Unsteady rear face temperature measurements are confronted to numerical results in order to validate the thermo-chemical model formulation and be able in a next step to study the fire/composite interactions through a coupled aerothermal approach.