大量工程实际案例显示,地铁转向架的疲劳失效与结构的模态共振息息相关。若整车与设备和转向架的模态不合理匹配,轨道车辆可能出现异常振动和噪声。因此,必须对地铁车辆转向架进行模态分析和错频设计,以确保平稳运行、减少结构振动和噪声,提高车辆的安全性和乘坐舒适性。采用车辆在运行状态环境激励下模态识别方法,辨识了转向架在镟轮前后、不同载重工况下的构架模态参数,根据测试结果可知,镟轮前后基本不影响构架的模态参数,但随着载重增大,各阶模态频率普遍升高,这与车辆载重增大影响转向架空簧刚度变大等边界约束状态有关。通过将测试结果对比自由状态和约束状态下的转向架构架仿真分析结果可知,应该尽可能的去模拟实际的边界条件约束状态,以保证有限元模型的准确性。这为后续学者研究模态错频设计提供了基础。

A large number of practical cases have shown that fatigue failure of subway turnstile structures is mainly caused by modal resonance. If the modal characteristics of the entire vehicle, equipment, and turnstile are not properly matched, abnormal vibrations and noise may occur in the rail vehicles. Therefore, it is necessary to conduct modal analysis and mistuning design of subway vehicle turnstiles to ensure smooth operation, reduce structural vibrations and noise, and improve the safety and ride comfort of the vehicles. By adopting a modal identification method for vehicle turnstile under operating environmental excitation, the modal parameters of the turnstile structure before and after wheel profiling and under different loading conditions were identified. According to the test results, it can be concluded that wheel profiling has little effect on the modal parameters of the structure, but as the load increases, the modal frequencies of various orders generally increase. This is related to the increase in the stiffness of the turnstile air spring due to the increased boundary constraints caused by the increased load. By comparing the test results with the simulation analysis results of the turnstile structure under free and constrained states, it is found that it is necessary to simulate the actual boundary constraint conditions as much as possible to ensure the accuracy of the finite element model. This provides a basis for subsequent researchers to study modal mistuning design.