Ultrasonic plastic welding (UPW) is a promising method for joining carbon fiber reinforced thermoplastic (CFRTP). The interface temperature determines weld quality to a large extent. This paper numerically analyzes the contact behavior and temperature characterization during welding using harmonic balance method (HBM). The simulation and experimental results show that amplitude and welding time are important factors determining the interface temperature. Increasing amplitude and welding time can significantly increase the interface temperature. Plunging speed and trigger force have little effect on the interface temperature. For nonlinear contact and heat generation, the results show that there is a certain separation between workpieces and the heat source is mainly friction heat generation in the early stage of welding. With the progress of welding, there is no separation between the workpieces and viscoelastic heat generation begins to dominate.
Keywords: carbon fiber reinforced thermoplastic (CFRTP); harmonic balance method (HBM); heating generation; ultrasonic welding; welding parameters.