A MODEL TO PREDICT THE THROUGH-THICKNESS DISTRIBUTION OF HEAT-GENERATION IN CROSS-PLY CARBON-FIBER COMPOSITES SUBJECTED TO ALTERNATING MAGNETIC-FIELD

A theory of local and global mechanisms of heat generation and distribution in carbon-fiber-based composites subjected to an alternating magnetic field has been proposed. A model is developed which predicts the strength and distribution of thermal generation through the thickness of carbon-fiber-based laminated composites. Earlier work established the distribution of point voltages in the plane of the laminate which exist in the form of potential differences between fibers in adjacent plies in a cross-ply or angle-ply laminate system. In the present work, a capacitive layer microstructure is formulated which models the actual fiber-reinforced-polymer microstructure from a square-packing assumption to a series of conductive parallel plates. From this capacitive layer analogy, an effective parameter of heating, gamma, is defined which establishes the distribution of heating through the thickness. Extreme gradients in this thermal source can exist with peaks occurring at the interfaces of ply/ply orientation changes. An optimization study establishes the effect of various micro- and macrostructural parameters on the parameter gamma. Several parametric studies are performed on a computer algorithm which calculates gamma to further analyze these effects.