基于等效结构应力的铝合金地铁车体疲劳寿命预测

Fatigue life simulation on aluminum subway car body based on equivalent structure stresses

为评估某铝合金地铁车辆的疲劳寿命,采用美国ASME标准中的网格不敏感的主S-N曲线法对该车焊缝进行疲劳寿命预测.用HyperMesh对车体进行有限元建模,并对焊缝处网格细化;用ANSYS计算焊缝处应力;运用自主开发的FE-Weld软件对其进行等效结构应力的计算和疲劳寿命的预测;对疲劳寿命不符合设计要求的结构进行改进和优化,改进后结构的疲劳寿命符合设计要求.网格不敏感的主S-N曲线法具有重要工程应用推广价值.

To evaluate the fatigue life of an aluminum subway vehicle,the weld line fatigue life of the vehicle is predicted by the mesh-insensitive master S-N method in ASME standard of the United States.The finite element model of the car body is built by HyperMesh and the mesh of weld lines is refined; the stress near weld lines is calculated by ANSYS; by the self-developed software FE-Weld,the equivalent structural stress is calculated and the fatigue life is calculated; the structures where the fatigue life cannot meet the design requirements are improved and optimized,and the fatigue life of the improved structure meets the design requirements. The mesh-insensitive master S-N curve method has great promotion value on engineering application.