Theoretical and Numerical Study on the Effect of TMD in Ground Borne Noise Control

The combined mass of wheelset and rail exhibits a simple harmonic motion on the resilient fastener. The natural resonance mode of this motion is called P2 resonance. P2 resonance typically happens at a frequency around 30–100 Hz proportional to the square root of the stiffness of the resilient fastener. Railway Groundborne noise (GBN) at the buildings near railway tunnels is associated with the vibration at the P2 resonance frequency of the rail. Tuned Mass Dampers (TMD) tuned to the P2 resonance frequency can significantly dissipate the ground-borne vibration energy. A TMD includes the mass-spring-damper system that counteracts the rail vibration and dissipates the energy at a resilient layer via amplified hysteresis motion of the oscillators. The theory and FEA simulation demonstrate the effect of the TMD on groundborne vibration reduction in this study. The results of the vibration reductions from FEA are compared with the laboratory test results.