High-resolution thermal analysis at thermoplastic pre-impregnated acomposite interfaces

Abstract

In situ consolidation of pre-impregnated thermoplastic composite requires as much as possible intimate contact as well as an appropriate molecular diffusion across the interface, where the intimate contact takes place. The last depends on the temperature that influences the molecular mobility. Thus, in order to evaluate the consolidation, first, we must describe accurately the composite surfaces and then, when placed in contact for manufacturing the laminate, a high-resolution simulation of the resulting thermal model must be accomplished to have access to the thermal history at the rough contact surface. In this paper, we proceed in three steps: (i) first the pre-preg surface is assimilated to a random process, a fractional Brownian motion, that can be characterized by two main descriptors, the topothesy and the fractal dimension; then, (ii) assuming the rough surface is represented by a Cantor set, the different parameters describing the fractal are determined from the statistical surface description; and finally, (iii) the resulting Cantor set representation will be considered as the geometrical support of a high-resolution thermal analysis accomplished within the proper generalized decomposition framework that allows exploring scales never until now attained.