Energy Spatial Distribution of Structure Noise Radiated from U-beam Slabs

Abstract

AbstractAt present, the application of U-beams in urban rail transit is gradually increasing, but researches about the bridge structural noise are still insufficient. This article took U-type girder as the research object and studied the structural noise distribution on the basis of energies in different frequency band. Firstly, the dynamic response of the bridge under vehicle load was acquired with the combination of finite element simulation method and field test. Secondly, the structure-acoustic coupling finite element-infinite element model of the U-beam was established, and noise fields of the whole U-beam, the floor and the wing slabs were calculated respectively. By calculating the energies contribution of the sound field point in different frequency bands, the spatial distribution of the radiation noise of the floor and the wing slab in the above frequency bands were obtained. The results show that in the frequency range of 20–200 Hz and the main frequency band (40– 63 Hz), the floor plays a major role in most areas of the whole noise field, and the main influence domain of wing slabs is located in the sector area around wing slabs. In the frequency range of 100–160 Hz, the floor mainly contributes to the acoustic energy of the sector region above and below the U-beam.