Contribution Source and Spatial Distribution of Concrete Box Girder Low-frequency Noise in Rail Transit

Abstract:

By taking double-line concrete simply supported box girder of rail transit as the research object, a vehicle-track-box girder finite element model and a box girder structure-borne vibration-radiation noise finite element model-infinite element model were established. Combined with field tests, the sound pressure distribution of whole box girder and each plate was obtained by the model, and the sound pressure contribution of each plate was analyzed. The results show that the finite element-infinite element model can accurately predict box girder structure-borne noise. The contribution to the sound field of web plate is less. The sound pressure of the near field is mainly affected by bottom plate, followed by wing plate. The sound pressure of the far field is mainly affected by bottom plate and top plate. In the space below bottom plate, the noise radiated by bottom plate dominates the sound field. At the same height of the box girder, the sound pressure contribution of roof plate is slightly larger than wing plate, and these two plates play a major role. In the area above roof plate, the sound pressure contribution of roof plate is much larger than other plates.

Key words:urban rail transit;box girder structure-borne noise;finite element-infinite element;plate sound pressure contribution;spatial distribution of sound field