Analysis of the laser-assisted forming process of CF/PEEK composite corner structure: Effect of laser power and forming rate on the spring-back angle

Abstract Carbon fiber-reinforced polyether ether ketone (CF/PEEK) is commonly used in the aerospace industry due to its high specific strength. The laser-assisted forming process shows potential to enhance the efficiency of forming thermoplastic composites and enabling in situ forming. However, when forming CF/PEEK corner structures with laser assistance, the shape accuracy of the part is limited by the spring-back resulting from prepreg bending. This article focuses on investigating the phenomenon of bending spring-back in thermoplastic composite parts. Through laser-assisted heating forming experiments and finite-element simulations, the effects of laser power and forming rate on the spring-back angle of single-layer CF/PEEK parts are analyzed. The process parameter distribution curve for achieving the minimum spring-back angle is determined. The corner structure demonstrates the least spring-back deformation, with a spring-back angle of 1.77°, at a forming rate of 1,700 mm/min, and a laser power of 63 W. At lower temperatures, the spring-back deformation is mainly influenced by the residual stress. The main mechanism of spring-back deformation of resin at high temperatures is the increase of bending caused by deconsolidation. This study offers theoretical guidance for achieving precision molding of multilayer thermoplastic composite bending structures.