Tensile stress-strain analysis of resistance spot weld using non-linear FEM with experimental verification

Abstract

This research presents an investigation on stress-strain behavior induced by resistance spot welding followed by a tensile shear test. The spot weld is modeled according to standardized dimensions for tensile tests with the main material properties of Cu as the electrode and low carbon steel S235 as the plates with 1 mm thickness, which include electric conductivity, resistivity, and heat transfer coefficient for the solid body as well as the contact interface. The FEM simulation is conducted using the process parameter of current between 6,000 A and 15,000 A, force at 5,000 N, and different stages of time following the welding process and tensile test, which is carried out after releasing both of the electrodes and material reaches the initial temperature with contact clamp velocity of 5 mm/min. To ensure the glued elements between the plates, a subroutine in MSC Marc/Mentat is used in the simulation with defined temperature. The outcome of simulation results will be verified with a series of experiments. It is expected that simulation will give good agreement compared to experimental analysis within an acceptable range of error.