Structure-borne Noise Differences of Metro Vehicle Running on Different Tracks

Abstract

A floating-slab track (FST) increases the interior noise and reduces the passenger's acoustic comfort. A study combining experimental measurement and numerical simulation was conducted to reveal the characteristics of internal structure-borne noise on different tracks and improve riding comfort. A field measurement was taken to analyze the essential interior noise characteristics on different tracks with different speeds. A noise prediction model was built by combining a vehicle-track coupling model, the structural finite element method and the acoustic boundary element method to predict the interior noise and study the panel contribution for noise control. The results show that the sound pressure level (SPL) of FST is 5 – 10 dB higher than the ordinary monolithic track (OMT). The curve section is 1 – 4 dB larger than the straight section. In the range of 90 – 110 Hz and 135 – 150 Hz, the SPL of FST condition is higher than that of OMT condition, with a maximum difference of 12 dB. And the SPLs at five ISO positions all have peaks at 30 Hz and 90 Hz frequencies, and the sound pressure fluctuates wildly at 100 Hz. The vibration at 90 Hz is relatively violent, which leads to more significant noise, but at 110 Hz, that is small. At different frequencies, the contribution of the panels to the sound pressure in the carriage is different, and the acoustic contribution of these panels may be the opposite.