扣件胶垫温变特性对车辆-轨道垂向耦合动力响应的影响分析

Analysis of Influence of Temperature Variation Characteristics of Fastener Rubber Pads on Vehicle-track Vertical Coupling Dynamic Responses

为了更加科学的表征扣件系统的温变力学特性,以此实现车辆-轨道耦合振动的精确预测,以高速铁路WJ-7B型常阻力扣件的扣件胶垫为研究对象,采用动态力学分析仪对扣件胶垫进行温度扫描试验,将试验所得的模型参数与基于格林函数法建立车辆-轨道垂向耦合动力学分析模型相结合,采用虚拟激励法分析扣件胶垫温变对车辆、轨道的结构振动响应的影响规律。计算结果表明:扣件胶垫的模量值和损耗因子具有明显的低温敏感性;扣件胶垫的温变特性对车体的振动响应基本无影响;转向架、轮轨力、轮对、钢轨在中频段内的振动响应峰值频率随温度降低均向右迁移,峰值减小;扣件胶垫的刚度和损耗因子在玻璃化转变区数值较大,导致轮轨耦合系统的刚度和损耗因子均较大,表现为振动主频的右移和高频振动响应的衰减。

In order to more scientifically characterize the temperature-dependent mechanical characteristics of the fastener system and realize the accurate prediction of vehicle-track coupling vibration,the temperature scanning test of the rubber pad of the WJ-7B constant resistance fastener of high-speed railway was carried out using dynamic mechanical analyzer.The model parameters obtained from the test were combined with the vehicle-track vertical coupling dynamic analysis model established based on Green’s function method.The influence law of temperature variation of the fastener rubber pad on the structural vibration responses of vehicles and tracks was analyzed using virtual excitation method.The calculation results show that the modulus value and the loss factor of the fastener rubber pad have obvious low temperature sensitivity.The temperature variation characteristics of the fastener rubber pad have little effect on the vibration response of the car body.The peak frequencies of vibration responses of bogie,wheel-rail force,wheel pair and rail in the middle frequency band move rightward with the decrease of temperature,and their peak values decrease.The stiffness and loss factor of the fastener rubber pad are relatively large in the glass transition region,resulting in relatively large stiffness and loss factor of the wheel-rail coupling system,which is manifested by the rightward shift of the main frequency of vibration and the attenuation of the high-frequency vibration response.