橡胶浮置板式轨道结构竖向振动分析模型

应用轨道段组合单元, 建立了能反映橡胶浮置板式轨道结构竖向振动特性的动力分析模型。在模型中, 钢轨模拟为连续弹性支承的Euler梁; 浮置板视为弹性薄板, 用有限元法中的纵横向有限条带单元进行离散; 钢轨扣件及橡胶支座模拟为线性弹簧和阻尼。基于弹性系统动力学总势能不变值原理和形成系统矩阵的“对号入座”法则, 建立了地铁列车-橡胶浮置板式轨道竖向振动方程, 并对车辆和轨道结构的动力特性进行了数值分析。计算结果表明: 地铁列车通过广州地铁二号线橡胶浮置板式轨道时, 轮重减载率最大值为0.597, 车体竖向振动加速度最大值为0.846 m.s^-2, 浮置板式轨道系统的隔振效率为20%~27%, 因此, 车辆-轨道结构竖向振动分析模型能够准确描述地铁车辆和橡胶浮置板式轨道结构间的动力特性。

Analysis model of vertical vibration for rubber floating slab track

According to the structural vertical vibration characteristics of rubber floating slab track, a composite element dynamic analysis model of track section was established.In the model, Euler beam element with continuous elastic supports was used to simulate steel rail.Floating slab track was taken as elastic thin plate and was discreted by longitudinal and lateral directional finite strip elements.Linear spring and damp were regarded as fastener and rubber support.Based on the principle of total potential energy with stationary value in elastic system dynamics and the "set-in-right-position" rule for formulating system matrices, the total potential energy of vertical vibration of train and track was obtained and the matrix equation of vertical vibration was established to analyze the vibration properties.Analysis result indicates that the maximum reduction rate of wheel load is 0.597, the maximum vibration acceleration of car body is 0.846 m·s-2 and the vibration isolation efficiency of the track system is between 20% and 27%.Obviously, the vertical model accurately describes the dynamic response properties of vehicle and track.