【摘要】 以减振CRTS-Ⅲ型轨道系统为研究对象,基于车辆、轨道、桥梁系统二维模型,利用动柔度法分别计算车辆和轨道系统的动柔度,建立频率域的车辆-轨道耦合模型,计算桥梁振动加速度并与常规CRTS-Ⅲ型轨道系统相比较。采用有限元法计算桥梁结构近场点和远场点噪声,探讨桥梁各子结构板对近场点和远场点噪声的声贡献率。计算结果表明:与常规CRTS-Ⅲ型轨道系统相比,铺设减振CRTS-Ⅲ型轨道系统的桥梁的振动峰值加速度减小69.9%,加速度平均值降低60.4%;近场和远场噪声计算点声压级分别降低8.4 dB、8.5 dB;桥梁顶板声贡献率分别达65.28%、68.30%。采用减振CRTS-Ⅲ型轨道系统能够有效降低桥梁结构噪声。声贡献率计算表明顶板振动是导致桥梁产生噪声的主要噪声源。更多还原

【Abstract】 The vibration-damped CRTS-III type track system is taken as the research object. Based on the twodimensional model of vehicle, track and bridge system, the dynamic compliance of the vehicle and track system is calculated. The frequency-domain vehicle-track coupling model is established. The bridge vibration acceleration is calculated and compared with that of the conventional CRTS-III type track system. The near-field and far-field noises of the bridge structure are calculated using the finite element method, and the acoustic contribution rates of the sub-structures of the bridge to the near-field and far-field noise are discussed. The calculation results show that compared with the conventional CRTS-III type track system, the vibration peak acceleration of the bridge is reduced by 69.9 %; the average acceleration is reduced by 60.4 %; the sound pressure levels at the near-field and far-field noise measurement points are decreased by 8.4 dB and 8.5 dB, respectively; the acoustic contribution ratios of the bridge roof reach 65.28 % and 68.30 % respectively. It is concluded that the use of vibration-reduction CRTS-III rail system can effectively reduce the noise of the bridge structure.The calculation of the acoustic contribution ratio shows that the roof vibration is the major noise source that causes the bridge noise.更多还原