腹板开孔的箱型梁结构噪声辐射特性分析

Structural noise radiation characteristics of box beams with web holes

箱型梁结构在列车的动力作用下产生振动并引发低频噪声,这种低频噪声对人体健康危害很大。以单跨32 m轨道交通箱型梁为研究对象,分别建立腹板无孔与腹板开孔两种工况下的三维实体有限元模型;在计算列车荷载作用下箱型梁振动响应的基础上,采用有限元-边界元耦合声学求解方法,分析计算腹板开孔的箱型梁结构噪声辐射特性。结果表明:腹板开孔使箱型梁跨中顶板和底板的垂向振动均有所降低;腹板开孔使箱型梁结构噪声衰减方向发生改变,在梁体下方及远场点有较好的降噪效果,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依据。

Under the action of dynamic loads of trains,box beam structures vibrate and radiate low-frequency noise being harmful to human health.Taking a 32m rail transportation box beam as a study object,the finite element method was adopted to establish two models of the box beam,one with web holes and another without web holes.After calculating the vibration response of the box beam under the action of a train,the structural noise radiation characteristics of the box beam with web holes were analyzed by adopting the finite element-boundary element coupled acoustic solving method.The results showed that web-holes can reduce vertical vibrations of the box beam top and bottom plates;web-holes can change the box beam structural noise attenuation direction and the box beam has a good noise reduction effect below the box beam and at far sites.The study results provided a theoretical reference for the design of urban rail transportation box beams to reduce vibration and noise.