A Numerical Model for the Thermoplastic Welding Process

Thermoplastic composites offer advantages over thermoset composites, such as welding, which allows for complex geometries and eliminates drawbacks of mechanical fastening and adhesive bonding. Most thermoplastic resistance welding studies rely on experiments, and reliable models are needed for wider applications. In this paper, a numerical model for the thermoplastic welding process is proposed. The model is based on one-dimensional temperature distribution around the joint interface obtained from the transient heat conduction equation. To evaluate the bond strength, a bonding model that considers intimate contact and autohesion was used. The material and the thermal properties as well as the processing parameters were obtained from the literature. Eight modeling conditions were investigated, and the results were discussed. The model proved useful for conducting parametric studies, which can assist in the selection of processing parameters for future experimental tests. It provided an overview of the temporal evolution of the intimate contact, autohesion, and degree of bonding mechanisms along the weld thickness under various modeling conditions for the APC-2/PEEK composite.