基于瞬时边界元的轨道交通高架槽形梁桥声辐射特性及影响分析

Sonic Radiation Characteristics and Influence Analysis of the Trough Girder Beam Bridge Based on Transient Boundary Element Method

为了精准预测列车通过轨道交通高架槽形梁桥时诱发的结构噪声,分析梁底板厚度对声辐射的影响,结合有限元-瞬时边界元法,采用多体动力学软件SIMPACK和有限元软件ANSYS协同联合仿真分析法,建立了车桥耦合系统振动分析模型以及槽形梁结构声辐射有限元/边界元模型。分析了列车荷载作用下槽形梁桥的声辐射特性,探讨了底板厚度对槽形梁结构噪声的影响。研究表明:地铁列车以80km/h的时速通过槽形梁桥时,桥面板的振动及桥梁结构噪声主要集中在底板附近;随着底板厚度的增加,槽形梁桥结构辐射噪声近声场处降低较为显著,对结构远声场有一定程度的影响。分析结果可为轨道交通槽形梁结构减振降噪提供一定的参考。

In order to predict accurately the structure noise on the elevated rail transit trough beam induced by passing trains,analyze the influence of plate thickness on the sonic radiation,combined with the finite element transient boundary element method,a vibration analysis model of vehicle bridge coupling system and a finite element/boundary element model of the trough girder structural acoustic radiation are established by adopting the collaborative joint simulation analysis method of multi-body dynamics software SIMPACK and finite element software ANSYS.Through analyzing the vibration and acoustic radiation characteristics of beam bridge under train load slot,the influences of the plate thickness on the bottom beam structural noise are discussed.The result shows that when the subway train passing through the trough girder bridge at the speed of 80 km/h,the bridge deck vibration and the structural noise are mainly concentrated on the near bottom;with the increase of plate thickness,the trough bridge structure radiation noise is reduced significantly in the near sound field,which has some influence on the far sound field to a certain extent.This research provides a theoretical basis for the noise reduction of rail transit trough beam structural vibration.