Numerical methods in simulation of resistance welding

Finite element simulation of resistance welding requires coupling between mechanical, thermal and electrical models. This paper presents the numerical models and their couplings that are utilized in the computer program SORPAS. A mechanical model based on the irreducible flow formulation is utilized to simulate plastic deformation and the resulting distribution of stress, a thermal model based on transient heat transfer is used to determine the distribution of temperature, and a steady-state electrical model is employed to calculate the distribution of electrical potential and current density. From a resistance welding point of view, the most essential coupling between the above mentioned models is the heat generation by electrical current due to Joule heating. The interaction between multiple objects is another critical feature of the numerical simulation of resistance welding because it influences the contact area and the distribution of contact pressure. The numerical simulation of resistance welding is illustrated by a spot welding example that includes subsequent tensile shear testing