基于等效结构应力的铝合金地铁车体疲劳寿命预测

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.

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

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.