摘要
混凝土箱梁在列车动荷载作用下会产生振动进而辐射低频结构噪声,影响沿线居民生活品质。以一跨高速铁路32m双线混凝土简支箱梁为研究对象,对箱梁板厚、翼缘斜撑、翼缘横隔板对结构噪声的影响进行研究。首先,基于车辆-轨道-桥梁系统频域模型求解扣件力;然后,将频域扣件力施加在桥梁-轨道有限元模型中进行谐响应分析求解箱梁振动。最后,利用边界元法以节点位移为边界条件求解桥梁结构噪声最大声压级。结果表明:在满足受力的前提下适当增加板厚可有效降低桥梁结构噪声;增加腹板厚度桥梁结构噪声降噪量最好,腹板厚度增大4 cm时结构噪声减小3 d B(A)~5 d B(A);设置翼缘斜撑可降低桥梁结构噪声约10 d B,斜撑间距4 m为宜,而对A计权声压级降噪效果不明显;设置翼缘横隔板可降低结构噪声约9 d B,三角隔板和弧角隔板降噪效果相当。
The vibration and radiation low-frequency structural noise of box girders induced by the dynamic loads of trains may greatly affect the life quality of the residents adjacent to the track. In this paper, with a 32 m-long concrete simplysupported box girder of a double-line high-speed railway track as the object, the influences of plate thickness, flange diagonal bracings and flange diaphragms on structural noise were studied. First of all, the fastener＇s force was solved in the frequency domain based on the vehicle-track-bridge model. Then, the fastener＇s force was applied to the bridge-track finite element model to obtain the vibration situation of the box girder through the harmonic response analysis. Finally, using boundary element method, the maximum sound pressure level of the structural noise radiated by the girder was solved with nodal displacement as the boundary condition. The results show that properly increasing the plate thickness can effectively reduce structural noise on the premise of meeting the requirements of structural loading; increasing web＇s thickness can reduce structural noise significantly. When the web＇s thickness increases by 4 cm, the structural noise can decrease by 3-5 d B（A）. Diagonal bracings can reduce the structural noise by nearly 10 d B, and the appropriate spacing of the bracings is 4 m.However, the noise reduction effect for A weighted sound pressure levels is not obvious. The diaphragm of flanges can reduce the structural noise by nearly 9 d B, and the noise reduction effects of the triangular baffle and the arc angle baffle are essentially the same.
作者
杨得旺
李小珍
高慰
YANG Dewang;LI Xiaozhen;GAO Wei(Depaxtment of Bridge Engineering, Southwest Jiaotong University, Chengdu 610031, China)
出处
《噪声与振动控制》
CSCD
2018年第A01期193-198,共6页
Noise and Vibration Control
基金
国家自然科学基金资助项目(51378429)
国家863计划资助项目(2011AA11A103)
关键词
声学
箱梁
结构噪声
板厚
斜撑
横隔板
vibration and wave
box-girder
structural noise
plate thickness
diagonal bracings
diaphragm
