Abstract:

In order to improve the simulation accuracy of the weld spot of the front longitudinal beam in the vehicle crash simulation, a spot weld model using the shell element to simulate the parent material and the single solid element to simulate the weld nugget and its heat affected zone was built by means of the software LSDYNA. The properties of the parent material and the failure parameters of the weld spot were acquired by tensile tests of the sheet and the weld spot cup respectively. The internal force of the spot weld model was investigated by the numerical KSII tests in various parent material mesh configurations. The simulations of the front longitudinal beam crash were performed by a validated finite element model of the longitudinal beam using spot weld models with sodid element and beam element respectively. The simulation results were compared with the sled test results in terms of the failure behavior of the spot weld, the deformation of the longitudinal beam and the acceleration of the sled. The study indicated that the spot weld model with solid element is better than that with beam element for better reliability and higher accuracy.

Key words: vehicle engineering, spot weld model, solid element, finite element, crash simulation, frontal longitudinal beam