Investigation on vibro-acoustic characteristics of high-speed railway steel-concrete composite bridge based on the combined FE-BE-SEA method

This paper presents a combined finite element-boundary element-statistical energy analysis (FE-BE-SEA) method to predict the vibro-acoustic characteristics of high-speed railway steel-concrete composite (SCC) bridge. The train-track coupling model is firstly introduced to accurately determine the forces transmitted to bridge, which are then imported into the established FE-BE model and SEA model. Among them, the former is adopted to calculate the vibration response in full frequency band and acoustic response at 20∼200 Hz, while for the noise part at 200∼2000 Hz, the latter is utilized for calculation. The on-site testing is carried out simultaneously to collect the measured results, which are compared with the predicted ones, validating the reliability and accuracy of the proposed method. Finally, a thorough discussion is conducted on the acoustic contribution and parametric analysis. The results indicate that the dominant frequency bands of deck and web radiated noise are below and above 200 Hz, respectively, ranking first and second in terms of overall acoustic contribution, followed by the diaphragm and flange. Reducing train speed, installing elastic fasteners, as well as increasing web thickness can significantly mitigate the vibro-acoustic responses from SCC bridge, but the effective frequency ranges for vibration and noise reduction are slightly different.