High-performance ultrasonic welding of continuous carbon fiber reinforced polycarbonate composites: Synergizing simulation and experimentation

Ultrasonic welding has emerged as a highly efficient and environmentally sustainable technique for joining carbon fiber-reinforced thermoplastic composites (CFRTP). Polycarbonate (PC) serves as an ideal matrix material due to its excellent impact resistance, thermal stability, and cost-effectiveness. This study investigates the ultrasonic welding of obliquely woven carbon fiber-reinforced polycarbonate (CF/PC) composites, integrating both simulation and experimental exploration. A model for interfacial frictional heat generation and adhesion evolution, neglecting viscoelastic heating, was developed to predict temperature profiles and resin adhesion dynamics at the welding interface, validated by experiments. Additionally, the study conducted a detailed simulation analysis of four common lap joint configurations, providing insights to guide experimental research and optimize joint design. The effects of welding pressure and time on joint strength were explored, revealing that the optimal parameters for a 1.8 mm thick CF/PC composite are 2.0 bar pressure and 1.2 s welding time. These parameters yielded exceptional mechanical performance, with shear strength of 18.05 MPa and peel strength of 2.21 MPa. Microscopic analysis revealed that the primary failure modes were interface fiber-resin delamination and resin matrix shear failure, with minimal fiber breakage. These results contribute to optimizing the ultrasonic welding process, advancing CFRTP welding technology in engineering.