Weld Quality Prediction in Ultrasonic Welding of Carbon Fiber Composite Based on an Ultrasonic Wave Transmission Model

Ultrasonic welding has been widely used in joining plastic parts since it is fast, economical, and suitable for automation. It also has great potential for joining thermoplastic composite structures in the aerospace and automotive industries. For a successful industrial application of ultrasonic composite welding, it is necessary to have effective weld quality prediction technology. This paper proposes a model for weld quality prediction by establishing a correlation between ultrasonic wave transmission and welding process signatures. The signatures, welding power, and force are directly related to the weld quality. This model is used to predict the weld quality with three contact conditions and validated by experiments. The results show that the quality model performs well when a centralized and consistent contact condition is achieved. The model provides a process physics-based solution for the online weld quality prediction in ultrasonic welding of carbon fiber composite.