基于车桥耦合的高架槽形梁结构噪声影响分析

Analysis for the Structure Noise of Simply Supported Trough Girders Considering Vehicle-bridge Vertical Interaction

为了探讨列车通过轨道交通高架槽形梁时诱发的结构噪声,以某拟建30 m轨道交通槽形梁为研究对象,建立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。采用多体动力学软件Simpack建立列车的空间动力学模型,采用有限元软件Ansys建立槽形梁有限元模型,基于Simpack和Ansys相结合的联合仿真方法,获取轮轨激振力。在计算列车荷载作用下槽形梁结构振动响应的基础上,采用有限元-间接边界元耦合声学分析法,探讨底板厚度以及腹板高度对槽形梁结构噪声的影响。研究结果表明:底板厚度的增加可以降低槽形梁梁体正下方的结构噪声,但并非越厚越好,底板厚度对结构远声场有一定程度的影响,但降噪效果不明显;腹板高度的变化使槽形梁结构噪声辐射衰减方向有所改变,桥梁腹板两侧噪声辐射衰减速度较快;桥梁底板正上方的结构辐射噪声最强区域有缩小趋势;分析结果可为轨道交通槽形梁结构减振降噪优化设计提供一定的理论参考依据。

The structure noise of simply-supported trough girders in urban rail transit is analyzed. The model of vehiclebridge coupling system for a 30 m reinforced concrete trough girder is built, and the corresponding finite element model and the acoustic boundary element model are established. The train’s spatial dynamics model is established by means of Simpack software, and the finite element model of the girder is established by Ansys software. Based on the combination of Simpack and Ansys codes, the wheel/rail exciting force is obtained. On the basis of calculating the vibration response of the trough girder under the action of train load, and using finite element - indirect boundary element hybrid acoustic analysis method, the influence of the bottom plate thickness and height of the web on the trough girder structure noise is discussed. The results show that increase of the thickness of the bottom plate can reduce the structure noise of the trough girder, but it does not mean that the thicker the bottom plate is, the better the noise reduction effect is. When the thickness of the bottom plate reaches a certain value, its influence on the noise reduction effect of the structure is limited. Variation of the web height can alter the direction of radiation attenuation of the bridge structure noise, and the structure noise radiation on both sides of the bridge attenuates fast. The radiation noise of the structure above the bottom plate is the strongest, but it has a tendency to decrease with the variation of the web height. The results of the analysis can provide some theoretical references for the optimal design of the rail transit trough beam structure.