为了探究钢板结合梁桥的振动噪声,建立车-轨-桥耦合动力分析模型,获得了列车与桥梁的动力反应,后将此动力反应作为声学边界条件求解得到了钢板结合梁桥的结构噪声辐射,并对噪声辐射影响参数进行了探究.研究表明,列车过桥时,桥梁的结构位移呈现出周期性变化,各测点的竖向加速度均大于横向加速度;全桥结构噪声表现为全频段内均有衰减,高频区段衰减速率较低频段快;当车速提高时,各场点的总体声压级逐渐变大,车速从 200 km/h 升至260 km/h时,各场点声压级的上升幅度更大;双向行车时总体声压级显著增加,但各板件在峰值声压级时的贡献量比例无显著变化;有板肋时,顶板声压级贡献量较上翼缘板的更大,无板肋时则相反.添加板肋能够对局部结构进行优化,但对于整体的降噪效果影响不大.本桥板肋布置间距宜在 5.2m左右.
Coupled Vibration and Structural Noise Analysis of Steel Plate Combined with Continuous Girder Axle
In order to investigate the vibration noise of the steel plate bonded girder bridge,this paper establishes a vehicle-rail-bridge coupled dynamic analysis model to obtain the dynamic response of the train and the bridge,and then solves this dynamic response as the acoustic boundary conditions to obtain the structural noise radiation of the steel plate bonded girder bridge,and investigates the noise radiation impact parameters.The study shows that when the train crosses the bridge,the structural dis-placement of the bridge shows periodic changes,and the vertical acceleration of each measurement point is larger than the lateral acceleration.The structural noise of the whole bridge shows attenuation in the whole frequency band,and the attenuation rate of the high frequency band is faster than the low fre-quency band.When the speed increases,the overall sound pressure level of each field point gradually becomes larger,and when the speed increases from 200 km/h to 260 km/h.The rise of the sound pres-sure level of each field point is the overall sound pressure level increases significantly in two-way traffic,but there is no significant change in the ratio of the contribution of each plate to the peak sound pressure level;with plate ribs.The contribution of the top plate to the sound pressure level is greater than that of the upper flange plate,and the opposite is true when there are no plate ribs.The addition of plate ribs can optimize the local structure,but the overall noise reduction effect is general.The spacing between the plate ribs of this bridge should be about 5.2 m.
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