Stress distribution in carbon fiber-reinforced epoxy composites under the supercritical condition

Abstract

The recycling of carbon fiber-reinforced resin matrix composites is attracting more and more attentions, and many mechanical, chemical, and energy recycling methods have been proposed. Among those methods, supercritical solvent recycle technique has been developed recently. Hygrothermal treatment was applied first to the composites before the supercritical process. Numerical simulation method was used to carry out the calculation of the thermal stress, peel stress, and interfacial shear stress under both the hygrothermal and supercritical conditions, to identify the mechanism of structural damage of composites. It shows that the hygrothermal treatment reduced both the critical pressure and temperature, and accelerated the structural damage of composites under the supercritical condition. The temperature and pressure simultaneously impacted the mechanics performance of composites, while the temperature was the dominant factor to destroy the composites' structure. And, potential damage areas were located in the free end with two failure types mainly: interfacial debonding failure and stratified destruction. POLYM. COMPOS., 36:961–968, 2015. © 2014 Society of Plastics Engineers