Multifactor optimization for induction welding of carbon fiber reinforced thermoplastic composites based on response surface methodology

Induction welding of thermoplastic (CFRP) composites is one of the most promising welding techniques due to its high efficiency, flexibility, and selectivity of the heat area. However, the nonuniformity of the temperature field in the welding area poses a challenge to welding quality. In this paper, a multifactor optimization method devoted to the quality and efficient bonding of carbon fiber-reinforced polycarbonate (CF/PC) composites was presented. A transient three-dimensional finite element model was developed and validated to analyze the heating characteristics during the welding process. The mapping relationship between process parameters—equilibrium temperature and relative effective area were established to optimize the weld quality applying the response surface method. The single lap shear experiment was carried out to evaluate the mechanical properties of the welded joints, focusing on micro appearances and welding defects. The results show that the optimal process parameters are a current of 100A and a coil distance from the surface of 3.6 mm. Under the process parameter, the effective welding area is 0.3823 with an error of 4.25%. Highlights: The transient three-dimensional finite element (FE) model was established. The evaluation indicators for welding quality were proposed. The multifactor optimization method for process parameters was developed. The mechanical property and welding defects of welded joints is evaluated.