Analysis of spring-back deformation of CF/PEEK thin angled laminates by laser-assisted forming

Abstract

Laser-assisted forming is an advanced manufacturing method for thermoplastic composites, which has attracted much attention in recent years. Angled structure is the basic element of complex components. In this paper, the influence of forming characteristics and process parameters of laser-assisted forming on the angle deviation of angled thermoplastic laminates is studied. The results show that thin angled laminates with no more than 7 layers of thermoplastic tapes manufactured by laser-assisted forming have angles larger than that of the mold, that is, the spring-back deformation. Laser power, consolidation force and the number of layers have significant effects on the spring-back deformation. The local heating and pressing, and the fast cooling rate during laser-assisted forming cause large residual stress in the samples, which is the main reason for the spring-back deformation. In addition, the effect of repass treatment on spring-back deformation is studied. It turns out that the repass treatment can significantly reduce the spring-back deformation. This is due to the prolonged time of samples at high temperature, which could relax the molecular chain and reduces the residual stress.