Vibration and Bridge-Borne Noise from Urban Rail Transit Trough Beam

Abstract

Vehicle-track-bridge dynamic interaction analysis is applied to compute local dynamic responses of a trough beam under urban rail transit train by mode superposition method. The modal acoustic transfer vectors (MATVs) are obtained by boundary element method. The bridge-borne noise at different field points is then computed based on the MATVs and Fourier spectra of the mode coordinate responses of the bridge. The numerical results show that the noise level is significantly affected by the train speed but hardly influenced by the fastening stiffness. The residents in the high-rise buildings near the bridge may be much affected by the bridge-borne noise.

Prediction and Analysis of Structural Noise from a U-beam Using the FE-SEA Hybrid Method

“…It can be seen from Figure 10 that the frequency corresponding to the peak values of the sound pressure levels of all plates in the near-field zone are at 63 Hz, which is consistent with the conclusion in [7] are mainly concentrated within the 40 Hz to 80 Hz frequency range. Therefore, this frequency band should also be the focus for noise reduction.…”

“…It was also noted that the noise from the railway structure has the widest radiation region and slowest attenuation rate at 63 Hz. Han et al [7] analyzed the effects of plate thickness and stiffening on the noise of U-beam construction using the modal superposition method. They pointed out that the bottom plates of the U-beam construction have a larger influence on the structure noise in the far field than its web plates, and increasing the thickness of the bottom plate is more effective in reducing the noise than increasing the thickness of the web plates.…”

“…In this paper, a vehicle-rail coupling model is established using the SIMPACK software to obtain the vertical wheel-rail interaction force. According to the modal density of the U-beam plates, FE and FE-SEA bridge models are established respectively for plates having lower modal density (lower than 5) and plates having higher modal density (higher than 5) by using the VA To analyze the contribution of each plate vibration on the total sound pressure of a certain point, the sound pressure contribution coefficient D c is introduced [7]:…”

“…The modeling strategy, where different types of models (FE and SEA models) are built on different frequency bands (frequency-dividing strategy) for different plates, is carried out according to whether the bending mode density under the wide band excitation is higher than 5 or not [17][18]. sound pressure level 70.6 dB at the 3 rd far-field point of the 2 nd model in [7], which proves the reliability of the proposed model. Table 3 compares the computation cost for each method.…”