Abstract: Considering the fact that spot-welds in most of the FE analyses of car crashes are modeled as a rigid beam, parameter study is performed by using FE calculation. It is found that the failure time of a rigid beam is highly dependent on the mesh size and the angle between the beam element and the connected surfaces, which means it is instable and unreliable to model the spot-weld to the rigid beam. Then, a new simulation technique of the spot-welds is put forward by using an elastic-plastic beam, which is independent of nodes. After simulation comparison, the elastic-plastic beam turns up to be a more suitable method to simulate the behavior of the spot-welds because of its insensitivity to small mesh size and stability and reliability in predicting the failure time of the spot-weld.

Key words: Elastic-plastic beam, Finite element method, Spot-weld connection, Vehicle crash simulation