Heat generation mechanisms during induction heating of cross-ply carbon fiber reinforced thermoplastic laminates

Induction welding is considered to be one of the most promising welding technologies for carbon fiber reinforced thermoplastic (CFRTP) composites. However, the uncertainty of heat generation mechanisms presents a challenge to regulating the temperature field uniformity. In this paper, a quantitative calculation method for the induction heating efficiency of various mechanisms was proposed for cross-ply CFRTP laminates. Combining electrical and thermal properties, the cross-ply CF/PEEK and CF/PPS induction heating experiments were designed to explore the quantity ratio of various heat generation mechanisms. The results show that the heat production at the junction is about 10⁶-10⁷ times that of fiber heating. The dielectric loss is dominant mechanism at the junction, and the proportions of heat generated by dielectric loss in CF/PEEK and CF/PPS laminates were 0.6688 and 0.8255, respectively. Furthermore, the temperature prediction model with various stacking sequences was established, showing a good agreement with the experimental temperatures.