Failure Load Evaluation of Resistance Spotweld Subjected to Tensile and Shear Loads

Resistance spot welds have been widely used in joining sheet metal parts/panels in automobiles. A modern car contains approximately 2000–5000 spot welds. Failure of the spot-weld is an important concern during crash analysis for safety design of automobiles. The strength of the spot weld is investigated using cross tensile and lap shear test samples. One set of test data (one material and thickness combination) is used to find the failure criteria parameters of a spot weld in an explicit FE-code (LS-DYNA). Using the calculated failure parameters of the spot weld, failure loads can be predicted in simulations representing another set of test data which comprises of materials of different thicknesses. The predicted failure loads are found to be in good agreement with experimental data.