考虑枕下胶垫超弹性本构的弹性长枕轨道动力仿真

Dynamic simulation of long elastic sleeper track based on hyperelastic constitutive models of ruber cushion under sleeper

为揭示枕下胶垫超弹性本构特征对弹性长枕轨道动力响应的影响,基于Mooney-Rivlin超弹性本构理论,建立车辆-轨道-隧道-土体空间耦合动力学模型,分析车辆荷载作用下轨道-隧道系统的动力响应,与等效刚度法进行对比,并探讨超弹性本构中枕下胶垫的合理硬度。研究结果表明:基于超弹性本构仿真得到的轨道各位置位移、加速度数据更真实准确;随着枕下胶垫硬度减小,隧道壁加速度有效值减小,但会放大轨枕垂向位移及下部结构75 Hz频段的振动;综合考虑轨道动力响应、振动传递特性及减振效果,建议弹性长枕轨道枕下胶垫的绍尔硬度取52。

In order to reveal the influence of rubber elastic cushion under the sleeper on the dynamic behaviors of elastic long sleeper track, a 3 D coupling dynamic model of vehicle-track-tunnel-soil was established based on Mooney-Rivlin hyperelastic constitutive theory. The dynamic responses of track-tunnel system were analyzed and compared with equivalent stiffness method, and the reasonable Shore hardness of elastic cushion was discussed.The results show that the displacement and acceleration data obtained by the hyperelastic constitutive method are closer to the measured results at different locations of metro track. The effective value of tunnel wall acceleration decreases with the decrease of the hardness of elastic cushion. The maximum of sleeper displacement and lowfrequency vibration near 75 Hz of the structure below the cushion are amplified. Considering the dynamic behaviors, vibration transmission and reduction, the ruber with about 52 Shore hardness is recommended as elastic cushion.