Front Side Member Crash Analyses Considering Dynamic Failure of a Spot Weld

Abstract

Consideration of the dynamic material properties and the fabrication history including spot welds is very crucial for accurate and efficient crash analyses of auto-body structures. A resistance spot weld is described as a rigid beam in a general finite element model without failure model of a spot. For accurate crash analyses, an appropriate description of a spot weld in the finite element model and its dynamic failure model has to be considered. In this paper, crash simulations of a front side member are carried out considering the dynamic material properties, the forming effect of each auto-body component, and the dynamic failure model of a spot weld. The resistance spot weld is characterized as a beam element connecting two shell elements of each sheet at the location of the weld. The crash experiment of a front side member was also carried out to compare its result with the numerical result. Examine numerical analyses were carried out the effect of the dynamic material properties, the fabrication history and the assembly method on the crash analysis results such as the reaction, the crushing distance and the deformed shape of auto-body structures. Results demonstrate that consideration of a spot weld failure enhance the numerical analyses for the accurate prediction of crash analysis results on the front side member.