Modeling and experimental investigation of induction welding of thermoplastic composites and comparison with other welding processes

A three-dimensional finite element model of the induction welding of carbon fiber/polyphenylene sulfide thermoplastic composites is developed. The model takes into account a stainless steel mesh heating element located at the interface of the two composite adherends to be welded. This heating element serves to localize the heating where it is needed most, i.e. at the weld interface. The magnetic, electrical, and thermal properties of the carbon fiber/polyphenylene sulfide composite and other materials are identified experimentally or estimated and implemented in the model. The model predicts the temperature-time curves during the heating of the composite and is used to define processing parameters leading to high-quality welded joints. The effect of the heating element size and input current on the thermal behavior is investigated, both experimentally and using the developed model. The welds quality is assessed through microscopic observations of the weld interfaces, mechanical testing, and observations of the fracture surfaces. A comparison with two other welding processes, namely resistance welding and ultrasonic welding is finally conducted.