车下设备橡胶元件热氧老化对高速列车车体模态的影响

Influence of Thermal Oxygen Aging of Rubber Components of Suspended Equipment on the Mode of High-Speed Train Body

摘要:

通过加速老化试验和动态力学性能试验，分析橡胶动态力学性能参数的变化规律。引入形状系数，提出V型橡胶减振元件的三向动刚度计算方法，采用非线性最小二乘法对橡胶元件动力性能试验数据进行拟合，获得橡胶粘弹性本构模型参数。结合橡胶粘弹性本构模型，以橡胶减振元件的动刚度为老化指标，建立橡胶减振元件动刚度性能演变模型。建立高速列车车体及吊挂设备耦合有限元模型，吊挂设备与车体间连接刚度采用所建立的动刚度性能演变模型，探究外部环境温度、激励频率以及热氧老化对车体与车下设备振动模态的动态发展影响。结果表明：低阶模态频率随动刚度的增大，均会有不同程度的增大。其中对一阶低频垂弯和一阶高频垂弯的影响较为明显。当减振元件动刚度值增大时，一阶低频垂弯模态频率向无吊挂设备时一阶垂弯频率靠近，同时其对应的幅值增大；一阶高频垂弯模态频率向更高频方向移动，其所对应的幅值下降。研究结果可为高速列车橡胶隔振元件的工程应用提供参考。

Abstract:

The variation law of dynamic mechanical performance parameters of rubber was analyzed through accelerated aging test and dynamic mechanical performance evaluations. The parameters of viscoelastic constitutive model of rubber were obtained by non-linear least squares fitting. A method for calculating the three-dimensional dynamic stiffness of V-shaped rubber damping elements was proposed by introducing shape coefficients. Using the dynamic stiffness of rubber damping components as the aging index， a dynamic stiffness performance evolution model was developed for rubber damping components. A finite element model of the high-speed train body and under vehicle equipment， as well as a rigid flexible coupling dynamic model of the high-speed train was developed to explore the effects of external environmental temperature， excitation frequency， and thermal oxygen aging on modal frequency， coupled vibration of the body and under vehicle equipment. The results show that the low-order modal frequencies will increase to varying degrees with the increase of dynamic stiffness. The impact on first-order low-frequency vertical bending and first-order high-frequency vertical bending is more significant. When the dynamic stiffness value of the damping element increases， the first-order low-frequency vertical bending mode frequency approaches the first-order vertical bending frequency without the suspended equipment， and its corresponding amplitude increases. The first-order high-frequency vertical bending mode frequency shifts towards higher frequencies， and its corresponding amplitude decreases. The research results can provide reference for the engineering application of rubber vibration isolation components in high-speed trains.