Experimental Verification of a Cure Model for Closed Molds with Internal and External Heat Sources

摘要

A numerical model of the cure stage which includes the effects of internal and external heat sources is compared to experimental measurements. The necessity for creating the model arose from recent developments in the resistance heating method for curing thick closed-mold parts. Traditional resin transfer molding relies on temperature being applied to the mold through external heat sources, such as an oven, autoclave, or hot press. The exothermic reaction is initiated near the surface of the part. As the cure front moves to the center of the composite, an excessive amount of heat is generated which is not easily dissipated. Thus large temperature gradients and temperatures are created which lead to thermal stresses and resin damage, respectively. The resistance heating method passes current through conductive carbon fibers initiates the chemical reaction and the part cures from the interior toward the exterior. The dispersed internal heat sources can reduce both the temperature gradient and thermal spikes.