中文摘要：

交通荷载引起的桥梁振动辐射低频噪声严重危害居民的身体健康和生存环境,正确把握桥梁振动噪声辐射机理和准确预测声压水平,对评价及降低环境噪声污染具有重要现实意义。结合车桥耦合振动理论和声传播理论,建立了桥梁振动辐射瞬态噪声的有限元-边界元混合求解体系。结合一座三跨钢连续梁桥,对交通荷载作用下桥梁振动产生的瞬态噪声声场特性进行了实验分析和数值模拟。分析结果表明,该方法能够同时反映声场在时域和频域的分布规律,可全面评估车桥振动辐射噪声的声压水平和声场特性,并具有较好的精度。算例中的下承式钢箱梁桥由于桥面板刚度小,声辐射面大,在车辆荷载作用下辐射噪声水平较高,噪声主要由桥面板振动引起。车辆入桥及出桥时的冲击作用只影响桥梁支座附近的声场。桥面附近等高线形状基本为圆弧形,桥面中心线附近的声压大于横断面两侧。

英文摘要：

Low-frequency noise induced by vehicle-bridge coupling vibration is harmful to people＇s health and living environment.The investigation for the sound pressure level and the radiation mechanism of such kind of noise offers important accordance for assessment of environmental noise pollution and noise control.In this paper,the transient noise induced by vehicle-bridge coupling vibration is investigated by proposing a solving system based on FEM and BEM.A steel continuous bridge with three spans in service is studied as the case.The transient noise produced by vehicle-bridge coupling vibration is investigated by experiment and numerical simulation.Results show that the sound field properties in both time and frequency domains can be calculated by the proposed solving system,through which a more comprehensive assessment of sound pressure level and sound field distribution could be obtained.And the precision of the method is also validated.It is found that the sound pressure of the steel half-through girder bridge is great because the small stiffness and large sound radiation area of the steel plates.And the noise is induced mainly by the steel plates of the bridge.The traffic impacts while the vehicle traveling into and out of the bridge only affect the sound pressure in the neighborhood of the bridge abutment.The shape of contour lines in the area around the bridge deck looks like arcs.The sound pressures in the central area of the cross section of the bridge are greater than those in the two sides.