Integrated design of passive control methods for mitigating vibration and noise of rails in high-speed railway

Attachment of constrained layer dampers and dynamic vibration absorbers (DVAs) on rails are two effective passive control methods used for mitigating vibration and noise of railways at the source. An integrated passive control method in which constrained layer dampers and DVAs were simultaneously attached on the rail was proposed to attenuate the vibration and noise of the rail in a broad frequency range and to suppress the maximum vibration emitted by the first pinned-pinned resonance of the rail. The design method for the integrated application was developed based on the optimum design theory of DVA for multiple-degree-of-freedom damping structures. The vibration and noise reduction properties of the integrated control method were analyzed using a vibroacoustic model established based on the sequential finite element method–boundary element method and evaluated through laboratory tests. The results show that the integrated control method fully demonstrates the advantages of the two passive vibration control methods, which can improve the longitudinal transmission loss of the rail by 5.3 dB/m at the first pinned-pinned resonant frequency and reduce the maximum acoustic power of the rail by 7.8 dB(A) as well as achieve an overall rail noise reduction of 4.0 dB(A) within 3000 Hz. The vibration and noise reduction properties of the integrated control method are improved as the mass ratio increases in the frequency range above 600 Hz. The test results show that the integrated control method decreases the rail web vibration and rail noise by more than 40%.