轨道交通箱型梁腔室结构的减振降噪研究

轨道交通箱型梁在列车荷载作用下产生的低频振动与噪声对人体健康危害很大,针对箱型梁的减振降噪研究具有重要意义。将有限元振动分析理论与声辐射分析边界元法相结合,计算列车荷载作用下箱型梁的结构噪声,并对比分析不同的腔室结构对箱型梁结构噪声辐射的影响。计算结果表明:箱型梁场点结构噪声的辐射受振动水平影响较大;对于不同的腔室结构的箱型梁,跨中场点的最大线性声压级从大到小依次为单箱单室、单箱双室、单箱三室、双箱单室箱型梁;箱型梁采用双箱单室结构形式最有利于结构噪声的控制,且随辐射距离的增加,噪声辐射衰减越快;降低翼缘和腹板振动水平能够有效降低箱型梁结构噪声。分析结果可为城市轨道交通箱型梁的结构减振降噪设计提供一定的理论参考。

Box Beam Chamber Structure for Vibration and Noise Control in Urban Rail Traffic

Finite element method (FEM) and boundary element method (BEM) are applied to calculate noises radiated by box beam and (to) analyze the radiation levels of box beam with a variety of chamber. As the calculation results indicate, noise of box beam site structure is greatly influenced by vibration level; for box beam structures with different chambers, the maximum linear sound pressure level of inter-midfielder decreases from single cell single box girders to single box with double cells to single box with three cells to twin-box single-cell girder. Twin-box single-cell girder is the most ideal one to reduce structure noise of box beam, and the more distant the radiation is, the faster the attenuation of the noise. The reduction of structure noise of the box beam adopts positive correlation with that of vibration of the flange and web. The findings can provide reference for the design of the reduction of vibration and noise of urban rail transit box beam.