Abstract A multidisciplinary design optimization method of a lightweight car body for fatigue life prediction is presented in an attempt to minimize the coupling vibration interactions at different structural frequencies. A mathematical model is developed to simulate such coupling vibration interactions based on the theory of finite elements. The finite element model is integrated with a rigid-flexible coupled multibody dynamics model which was used to obtain load time histories. The obtained results demonstrate the effectiveness of the proposed approach in simultaneously attenuating the structural coupled vibration and improving the durability at several structural frequencies. The field structure dynamics stress verification is carried out and vehicle vibration characteristics are obtained under different operated vehicle speed. The measured dynamic stress is found to be in good agreement with the predictions of the mathematical model. Finally, the fatigue life prediction results of the weight-reduced car body structure before and after multidisciplinary optimization are compared and analyzed. The results also illustrate the multidisciplinary design optimization method can be applied in the durability design of railway vehicle critical structure components when subjected to complex loading environment.

中文翻译：

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用于疲劳评估的轻量化车身多学科设计优化

摘要 为了尽量减少不同结构频率下的耦合振动相互作用，提出了一种用于疲劳寿命预测的轻量化车身多学科设计优化方法。基于有限元理论开发了一个数学模型来模拟这种耦合振动相互作用。有限元模型与刚柔耦合的多体动力学模型集成在一起，用于获得载荷时间历程。获得的结果证明了所提出的方法在同时衰减结构耦合振动和提高多个结构频率下的耐久性方面的有效性。进行了现场结构动力学应力验证，获得了不同运行车速下的车辆振动特性。发现测得的动态应力与数学模型的预测非常吻合。最后，对多学科优化前后轻量化车身结构的疲劳寿命预测结果进行对比分析。研究结果还说明了多学科设计优化方法可应用于铁路车辆关键结构部件在复杂载荷环境下的耐久性设计。