Accurate Finite Element Modeling of Spot-Welded Region for Crash Analysis

Abstract

The resistance spot-welded region in most current finite element crash models is characterized as a rigid beam at the location of the welded spot. It is designed to be failed by some failure criterion which is a function of the axial and shear load at the rigid beam. The role of this rigid beam is simply to transfer the load across the welded component. The calculation of the load acting on the rigid beam is important to evaluate the failure of the spot-weld. In this paper, the numerical simulation is carried out to evaluate the calculation of the load at the rigid beam. The load calculated from the precise finite element model of the spot-welded region considering the residual stress due to the thermal history during the spot welding procedure is regarded as the reference value and the value of the load is compared with the one obtained from the spot-welded model using the rigid beam with respect to the element size, element shape and number of imposed constraints. Analysis results demonstrate that the load acting on the spot-welded element is correctly calculated by the change of the element shape around the welded region and the location of welded constrains. The results provide a guideline for an accurate finite element modeling of spot-welded region in the crash analysis of vehicles.