Development of 2-dimensional finite element modeling of resistance spot welding: 1^st generation model electric-thermal coupled

Resistance spot welding (RSW) is commonly used in the automotive and aviation industries. RSW is a process to join the overlapped metal sheet using Joule heating process and took place in less than a second. In order to reduce the cost of actual experiments, two type of simulation model based on 2D and 2D-axisymmetric finite element method (FEM) had been developed. It allows visual examination of welded joint by observing an increase in temperature within the overlapped sheets and can be used to predict the weld nugget size. RSW simulation was conducted by using ANSYS Parametric Design Language (APDL). The simulation model has a thickness of 1 mm each sheets metal and two different electric contact resistivity (ECR) which are Cu-Al and Al-Al resistivity. Welding simulation was performed by varying ECR and electric current (10 kA, 20kA, 25 kA, and 30 kA) with weld cycle time of 100 milliseconds. Melting temperature of aluminum is above 650°C so that the minimum target of simulation temperature is between 700-800°C. In this study, the result between 2D and 2D-axisymmetric were compared. The comparison showed that the aluminum with the 2D model reached above the melting temperature using ECR Al-Al 0.4, 0.1, 0.065 and 0.045 Ωm for weld current 10, 20, 25 and 30 kA, respectively. For the aluminum with 2D-axisymmetric model reached above the melting temperature using ECR Al-Al 18, 4, 2, and 1 μΩm for weld current 10, 20, 25 and 30 kA. As for the result, the 2D-axisymmetric model has more realistic value for ECR than 2D model.