随机不平顺激励下地铁整体道床式轨道振动特性研究

Study on the Vibration Characteristics of Metro Monolithic Track Bed under Random Irregularity Excitation

对地铁钢轨振动特性和支座反力的探究是研究地铁引起环境振动的关键。为研究整体道床式轨道的振动特性,基于二维车辆–轨道耦合动力学数值分析法和三维有限元法对不同车速、不同轨道不平顺激励工况下的钢轨垂向振动加速度、振动速度、钢轨位移、支座反力和时域轮轨力进行仿真计算。结果表明:车速一定时,由同种方法计算得到的不同轨道不平顺激励下钢轨最大的垂向位移、支座反力在数值上的差异在5%以内;同种轨道不平顺谱激励下,钢轨最大的垂向振动加速度、振动速度、垂向位移、支座反力以及时域轮轨力波动范围随车速增大而增大;在钢轨最大垂向振动速度、垂向位移和支座反力方面,基于二维数值分析模型的计算结果大于三维有限元模型的计算结果。根据两种方法计算所得的最大支座反力分别占单个车轮静载的40.46%和37.44%;同一车速工况下,钢轨最大的垂向振动加速度、垂向速度、垂向位移、最大支座反力以及时域轮轨力的最大变化范围均在美国五级谱激励条件下取得。

Exploring the metro rail vibration characteristics and support reactions force is the key for studying the subway-induced environmental vibration. In this paper, the vibration characteristics of integral ballast track are studied. The 2D vehicle-track coupling dynamics numerical analysis method and 3D finite element method are adopted to simulate the vertical vibration acceleration, vibration velocity, rail displacement, support reaction force and time-domain wheel-rail force of the rail under different vehicle speeds and different track irregularities. It is concluded that under the same speed and the different track irregularity, the differences of the maximum vertical displacement and the maximum support reactions force are all within 5 % using the same calculation method. Under the same track irregularity spectrum excitation, the maximum vertical vibration acceleration, vibration velocity, vertical displacement, support reaction force of rail and time-domain wheel-rail force fluctuation range increase with the increasing of vehicle speed. The vertical vibration velocity, vertical displacement and support reaction of rail obtained from the 2D numerical analysis model are larger than those of 3D finite element model.The maximum support reaction forces calculated by the two methods occupy the proportions of 40.46 % and 37.44 % respectively of the static load of a single wheel. At the same vehicle speed, the maximum vertical vibration acceleration, vertical velocity, vertical displacement, maximum support reaction force and the maximum variation range of wheel-rail force in time domain are obtained under the fifth-stage spectrum excitation of the United States.