Advances in Simulating the Processing of Composite Materials by Electromagnetic Induction

In the previous installment of this work, a flat spiral "pancake" type coil geometry and two different plate material types with large differences in electrical and thermal conductivity (structural steel and carbon fiber reinforced polymer composite) were used to perform static plate induction heating characterization experiments for the purposes of characterizing the heating behavior of both materials in preparation for continuous induction welding simulations. The static plate heating tests were validated experimentally in two Finite Element Analysis (FEA) software codes including LSTC's LS- DYNA® 980 (R7) solver. Following on from this initial work, a simulation test-bed has been created in order to study the continuous induction welding of two joining partners. The simulation test-bed mimics an experimental setup developed at the Institut für Verbundwerkstoffe (IVW) GmbH which considers a two-dimensional joining setup (two flat overlapping plates) and allows a more complete investigation of the thermal behavior that occurs during a continuous induction welding process. 3D surface plots of the top surface temperatures which are generated across the entire width of the joint as well as along its length can be investigated for different welding speeds and induction welding processing parameters. More importantly, the same types of surface plots can also be generated at the joining interface providing a complete view of the temperature profile that occurs during the process at this important location. This information can be used to decide on the optimum processing parameters to ensure that the material anywhere at the joining interface always remains within its prescribed upper and lower processing temperature limits. With its three-way physics coupling, the simulation test-bed also allows the consideration of further processing parameters including the influence of roller contact and additional top surface cooling via a moving air-jet nozzle for different induction welding speeds.