功率流理论在无砟轨道振动研究中的应用

摘要

为研究无砟轨道振动的能量特性,应用功率流理论推导了有限元功率流法的计算公式,并以桥上减振双块式无砟轨道为例说明了功率流理论在无砟轨道振动研究中的具体应用.研究结果表明:采用功率流理论可以解释振动能量在无砟轨道振动系统中分布、传递、存储和耗散的机理,为无砟轨道振动控制及优化设计提供理论基础;在桥上减振双块式无砟轨道结构中,钢轨的振动能量主要集中在100～2 000 Hz的中高频范围,而道床板和桥梁的振动能量主要集中在20 ～ 200 Hz频率范围内;在简谐荷载作用下,振动能量通过扣件和减振垫时的衰减量各达到24 dB.%To study the vibration energy characteristics of ballastless track,the power flow theory was applied to deduce the computational formula of FEM power flow method,which was then applied to the vibration study of double-block ballastless damping track on bridge.Results show that power flow theory can explain the mechanism of vibration energy generation,storage,transfer and consuming in ballasdess track vibration system.This provides the base of vibration control and optimal design for ballastless track.In the structure of double-block ballasdess damping track on bridge,the vibration energy of rail distributes mainly in 100 ～ 2 000 Hz,while that of slabs and bridge is mainly in 20 ～ 200 Hz.Under harmonic load the attenuation of vibration energy induced by fasteners and damping pads respectively reach to 24 dB.