Spot Weld Property Testing and Simulation Modeling with Failure Criteria

Abstract

Spot welds have been widely used in vehicle body assembly, and can affect the performance of a vehicle. This paper studies the mechanical properties of spot weld and utilizes those properties in the numerical simulation to predict the failure behavior of a spot-welded component. The mechanical properties of a spot weld are not easy to obtain due to the size of spot weld, and the non-uniformity around the weld zone. The study utilized the hardness measured on and around the spot weld, heat treated samples with the same hardness, and then performed the tensile tests on those heat treated specimens to obtain the corresponding mechanical properties. With those testing data, the numerical simulation model was then created based on the properties obtained. A single-spot-welded part was used to correlate the results of hardware tests and numerical simulation. The study compared the results of three different modeling schemes with those of the hardware test. The results showed that the simulation model with material properties assigned to their corresponding region provided better correlation with the hardware testing results.