关键词: 前保险杠；强度分析；载荷谱；振动疲劳；扭振工况

Abstract: For the problem of front bumper fractured in durability test of a light truck, this paper analyzes the reason of fracture from structural mode, strength and vibration fatigue. Based on the basic principle of vibration fatigue in frequency domain and the definition method of vibration fatigue load, the torsional fatigue simulation analysis model is established and the failure causes are identified. The result shows that the risk area is consistent with the real vehicle. At the same time, the structural optimization is completed for the risk position and passed the durability test, and the analysis method is verified effectiveness, the research results can provide a reference for solving similar problems of the light truck chassis structures.

Key words: Front bumper; Strength analysis; Load spectrum; Vibration fatigue; Torsional vibration condition