Composite embedded track structure considering temperature dependent characteristics for rolling noise reduction of inter-city railway system

Intercity railway will generate strong noise when passing through the surrounding residents, among which rolling noise is the main noise source and is difficult to control. A composite embedded track structure containing polymer material was fabricated to analyze its damping and rolling noise reduction characteristics. The damping characteristics of polymer materials of embedded track were tested by dynamic thermo-mechanical analyzer (DMA Q800). The frequency response function (FRF) of the embedded track system is tested by force hammer percussion method. The vibration of the embedded track is simulated by the the 2.5-dimensional finite element method (2.5D FEM) considering damping characteristics obtained by material test of DMA Q800. The sound radiation model of embedded track is developed by using 2.5-dimensional sound boundary element method (2.5D BEM). The model is verified by the test. The FRF, track decay rate, and wheel-rail force at different temperatures are analyzed. With the decrease of temperature, the elastic modulus and loss factor of polymer material of embedded track increase, which will affect the above results. Sound directivity and effect on wheelrail noise reduction of embedded track have been studied. The results show that the composite embedded track has good damping characteristics and noise reduction performance. Sound sensitivity analysis of loss factors of the three polymer materials of embedded track is carried out to improve embedded track noise reduction capability.