Sound transmission loss of windows on high speed trains

Yumei Zhang,Xinbiao Xiao,Zefeng Wen,David Thompson,Yue Wu,Zhihui Li,Giacomo Squicciarini

doi:10.1088/1742-6596/744/1/012141

Yumei Zhang, Xinbiao Xiao + Show 5 more

Open Access

https://doi.org/10.1088/1742-6596/744/1/012141

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Abstract

The window is one of the main components of the high speed train car body structure through which noise can be transmitted. To study the windows’ acoustic properties, the vibration of one window of a high speed train has been measured for a running speed of 250 km/h. The corresponding interior noise and the noise in the wheel-rail area have been measured simultaneously. The experimental results show that the window vibration velocity has a similar spectral shape to the interior noise. Interior noise source identification further indicates that the window makes a contribution to the interior noise. Improvement of the window's Sound Transmission Loss (STL) can reduce the interior noise from this transmission path. An STL model of the window is built based on wave propagation and modal superposition methods. From the theoretical results, the window's STL property is studied and several factors affecting it are investigated, which provide indications for future low noise design of high speed train windows.

Highlights

Interior noise is one of the key parameters affecting the comfort level of high speed trains
The three frequencies above are all independent of the boundary conditions; the mass-air-mass frequency can be influenced by the first bending mode of the plate the latter is sufficiently low in frequency not to influence the results in the present case
The values of these frequencies illustrate that the dip in the diffuse field Sound Transmission Loss (STL) at 260 Hz is associated with the “Mass-Air-Mass” resonance and that at 3000 Hz belongs to the “coincidence frequency”, both of which are a function of the angle of the incident sound field defined in figure 5

Summary

Introduction

Interior noise is one of the key parameters affecting the comfort level of high speed trains. Xin et al [11] applied the wave propagation method to study the sound insulation properties of finite double plate structures, and investigated the effect of the panel thickness, cavity thickness and the incidence angle. Interior noise and its source identification The interior and bogie area noise test results obtained are shown in figure 2 This shows that, after Aweighting, the interior noise is dominated by the region 630~1250 Hz with its peak at the 1000 Hz frequency band. As one of the main noise sources of interior sound, the bogie area noise may shed some light on this phenomenon It peaks in the region 630~1250 Hz where the A-weighted level is far higher than the rest of the frequency range. On the basis of this interior noise identification we can conclude that the window, as well as other panels from the roof and floor, has a contribution to the interior noise

Window’s vibration

Double panel cavity model

D2 4 a2b2

Model validation

Parameter study of window STL

Conclusion