轨道结构参数对钢轨和轨枕振动特性的影响

建立轨道结构三维实体有限元模型,同时考虑钢轨、轨下垫层、轨枕和道床,并与已有轨道结构振动模型的数值结果进行比较。结果表明,本文模型的数值结果在高频部分较合理,能够反映轨道结构高频振动特性。分析不同轨道结构参数对钢轨和轨枕振动特性的影响,这些轨道结构参数主要包括钢轨材料损失因子和钢轨质量、轨下垫层损失因子和垂向刚度、轨枕质量和损失因子、道床的刚度与阻尼特性等。分析结果表明,轨道结构参数的改变对钢轨和轨枕在不同频域范围影响不同,通过合理的轨道结构系统参数优化设置,可达到减振降噪效果。相关计算和分析结果可为低噪声轨道的设计提供依据与参考。

Effect of Structure Parameters of Railway Track on Dynamic Behavior of Rail and Sleeper

A linear 3D finite element model(FEM) for a ballasted track is established,in which the rails,fastening systems,sleepers and ballast are considered respectively.The model is verified with the theoretical predicted results and the test results by D J Thompson.It is found that the results by the present track model are more close to the test results in high frequency range than those theoretically predicted by D J Thompson.This model is available for predicting the dynamic characteristics and noise radiation of the track.The influence of the track structure parameters on the vibration and acoustic characterizes of the track is analyzed in detail.The structure parameters include the material loss factor and the mass of rail,the pad loss factor and its vertical stiffness,the loss factor and the mass of sleeper,as well as the ballast loss factor and its vertical stuffiness.The numerical results indicate that the track structure parameters have different effects on the dynamic behavior of the track in different frequency ranges.The related numerical results will be very useful in the optimum design of railway track structure parameters to reduce the vibration and noise radiation of the track.