DEMONSTRATION OF MODEL-BASED CONTROL OF THERMOPLASTIC CONTINUOUS RESISTANCE WELDING

Abstract

Integrated design can extend the lightweighting potential of structural composite components in the aerospace industry. However, with increased component complexity and size, aspects such as manufacturing complexity and costs predominate, which is why differential construction is still the state of the art today. Welding technologies, such as resistance welding, provide an approach for producing integrated fibre-reinforced high-performance thermoplastics structures. This publication highlights the current development work in the field of continuous resistance welding. This process uses Joule heating of a conductive insert to generate heat, locally melting the joint along the mating surfaces of the two consolidated components to be joined. In the present application, continuous resistance welding (CRW) relies on discretizing the application of current to the continuous electrical insert, welding locally under a mobile end effector. A model based on fundamental physics encompassing both electrical and thermal phenomena was developed and used finite element to simulate weld interface temperature based on initial setup parameters and characterized properties. A surrogate model was used to predict weld interface temperatures and a control scheme based on this prediction was used to demonstrate CRW on a robotic platform.