Acoustic radiation characteristics of the low-dynamic interaction rail

Abstract The low-dynamic interaction rail (LDIR) proposed in this study is designed to attenuate rail-radiated noise, addressing limitations in both conventional rail geometry and existing noise control methods. In contrast to conventional measures that apply damping materials to the rail surface or attach them to the rail side, the LDIR innovatively embeds the damping structure within the rail itself, optimizing the vibro-acoustic characteristics at the rail level. The vibro-acoustic characteristics of the LDIR are analyzed using the finite element methodand the acoustic boundary element method (BEM). Laboratory acoustic tests are conducted to compare the noise radiation differences between the LDIR and the Chinese National 60 kg/m (CN60) rail. The results indicate that the LDIR exhibits slightly lower natural frequencies and modal displacement at the critical vibration modes compared to the CN60 rail. With the application of the elastic-damping layer, the radiated sound pressure level (SPL) and total sound pressure level (TSPL) of the LDIR are markedly lower than those of the CN60 rail. The wheel-rail noise prediction model shows that the LDIR achieves optimal noise reduction under train operating conditions. This performance is obtained when the elastic-damping layer is made of polyurethane elastomer with an elastic modulus of 5,000 MPa. This study presents a novel solution for mitigating rail-radiated noise, while reducing trackside noise exposure levels and improving the acoustic environment of urban rail transit.