2010 Volume 34 Issue 6 Pages 490-499
In railway transport, it has been recently increasingly demanded to reduce the rolling noise that accounts for a great portion of the track wayside noise by a method easy to execute. Therefore, we have developed a new type device, called Rail Noise Isolating Material (RNIM). RNIM consists of two laminated layers, the inner one of which is made of viscoelastic sheet ; and the outer one of high modulus plate. In order to select the materials suitable for RNIM, the impact test was executed against several samples made by representative practical materials. As the test results, ethylene-propylene rubber (EPDM) foam was selected for the inner layer ; and damping or normal steel, for the outer layer. The noise reduction property of the selected sample (the damping steel for the outer layer), was examined by measurement of track wayside noise among train passage on a commercial line. As the result, it was found that the noise reduced by 2～3 dB with installation of RNIM.
