关键词: 激光焊接；超单元理论；密封条；疲劳分析；精细化疲劳模型；汽车尾门

Abstract: The purpose of this paper is to solve the problem of laser welding cracking in the fatigue condition of automobile tailgate. In order to reflect accurately the laser welding cracking in the tailgate fatigue condition, the super element theory was introduced to establish a refined model for laser welding fatigue analysis. Through the detailed model of laser welding near the crack area, a corrected multi-dimensional stiffness matrix was obtained, and the nonlinear material property calibration of the sealing strip was introduced, which simulated accurately the nonlinear dynamic performance of the automotive tailgate seal under the high strain rate, and effectively improved the calculation efficiency of laser welding of the vehicle tailgate and the risk prediction accuracy of fatigue cracking. Finally, the rationality and accuracy of the refined fatigue model were verified by relevant tests, which effectively improved the tailgate structure and reduced the experimental cycle and cost.

Key words: Laser welding; Super element theory; Sealing strip; Fatigue analysis; Refined fatigue model; Automobile tailgate