Numerical Simulation and Field Tests of Concrete Bridge-borne Low-frequency Noises
Numerical Simulation and Field Tests of Concrete Bridge-borne Low-frequency Noises
复制标题
DOI：
--
复制
发表时间：
2013
期刊：
影响因子：
--
通讯作者：
Wu Ding-jun
中科院分区：
文献类型：
--
作者：
Wu Ding-jun
提出了一种数值方法来模拟时间，研究了列车运行时混凝土桥载低频噪声的频率和空间特性，采用有限元法和振型叠加法求解列车-轨道-桥梁瞬态动力相互作用问题，重点研究了桥梁的局部高频振动，采用边界元法求解模态声传递向量，并对桥梁-轨道-桥梁瞬态动力相互作用进行了分析。通过模态声传递向量与桥梁模态坐标谱相乘，计算出各场点的声压谱，再利用快速傅立叶逆变换得到时域声压，并结合真实的城市轨道交通U型桥进行了振动和噪声的现场测试。通过对上海某预应力混凝土异形梁的振动分析，计算了该桥各部位的振动加速度，计算了不同场点处的声压，并与实测值进行了比较，发现计算结果与实测值吻合较好，时间历程和光谱的测量结果。
A numerical procedure was proposed to simulate the time,the frequency and the space characteristics of concrete bridge-borne low-frequency noises under moving trains.The finite element method and the mode superposition method were used to solve the transient dynamic train-track-bridge interaction problem with emphasis on local bridge vibration of high frequency.The boundary element method was applied to find the modal acoustic transfer vectors.The bridge-borne sound pressure spectra for various field points were then computed through multiplying the modal acoustic transfer vectors by the modal coordinate spectra of the bridge.The time-domain sound pressures were finally obtained with the help of the inverse fast Fourier transforms.Vibration and noise field tests were carried out with a real urban rail transit U-shaped prestressed concrete girder in Shanghai.The vibration accelerations at various parts of the bridge and the bridge-borne sound pressures at different field points were computed and compared with the measured data.It is found that the computed results agree well with the measured ones in terms of both time-history and spectrum.