MTMDs控制高速铁路简支箱梁桥车致振动噪声的研究

Structure-borne noise control with MTMDs for a high-speed railway simply supported box-girder bridge

轨道不平顺性激励引起桥梁结构振动,进而向空间辐射噪声。为了探明多重调谐质量阻尼器(MTMDs)对桥梁结构噪声的影响,选取32 m双线混凝土简支箱梁为研究对象,建立了移动集中力-桥梁-MTMDs耦合振动模型,根据桥梁的挠曲频响函数,求取了MTMDs的最优控制参数。在此基础上,采用瞬态有限元法和声学边界元法研究了不同数量调谐质量阻尼器对桥梁的减振、降噪效果。研究结果表明:MTMDs能有效控制桥梁的最大振动响应;由于MTMDs仅对一阶竖弯频率处的结构振动控制有效,使得其对结构噪声的控制效果不甚明显,对近轨侧25 m处声场的平均降噪效果约0.5 dB。

When a train runs across a bridge,the bridge is excited by dynamic forces acting on it because of the track irregularities,and the structure-borne noise radiated by the bridge raises evidently.To explore the influence of multiple tuned mass dampers（MTMDs） on structure-borne noise,the dynamic behavior of a two-track simply supported box-girder bridge with a span of 32 m was simulated as a case study.Based on a moving forces-bridge-MTMDs coupling vibration model,the optimal MTMDs parameters were derived and calculated with the flexural frequency response functions of the bridge,and then,the vibration and noise control effectivenesses of the bridge with and without MTMDs were compared respectively by applying the transient FEM and the acoustic BEM.The results showed that MTMDs are an effective device in reducing dynamic responses of a box-girder bridge;however,as the vibration control of MTMDs aims at the first flexural mode of the bridge,the structure-borne noise reduction is not as effective as the vibration reduction,and the average reduction of sound pressure level（SPL） is about 0.5 dB for the sound filed being 25 m far from the track.