支座刚度对高铁箱梁结构声辐射影响分析

随着箱梁结构在高速铁路中的广泛应用，其引起的结构振动和噪声问题日益受到关注。本文以京沪高速铁路32m简支箱梁为研究对象，首先建立高架轨道箱梁结构声学计算模型，该模型利用一1/10缩尺模型的仿真与实测结果验证，再通过建立高速列车-轨道耦合动力学模型计算作用箱梁结构上的作用力，并以此作为荷载边界条件施加于箱梁有限元模型上，计算箱梁结构的振动响应。最后，将箱梁结构振动响应作为声学边界条件，采用间接边界元法分析支座刚度对箱梁结构声辐射衰减规律的影响。研究结果表明：在3种不同刚度支座条件下，梁体声功率辐射影响主要集中在1～48Hz，支座刚度越大，声功率辐射值及峰值越小。箱梁最大声压级主要集中在1～20Hz；各场点声压级变化与声功率变化趋势较为接近；三种支座在相同场点的声压级变化趋势较为接近，但支座刚度越大，声压级越小；在同一场点，支座刚度越大，声压级峰值越小。在48～100Hz内，支座刚度值对梁体的声功率辐射及场点声压级大小影响不大。

Influence of Support Stiffness on the Structural Noise Radiation of the Box-girder in High Speed Railway

With the wide application of box girder structure in high-speed railway, the vibration and noise problems caused by the structure have attracted more and more attention. The paper takes 32m simple box girder of Beijing-Shanghai high-speed railway as the research object, structure noise calculation model of the elevated railway box girder is established, and the model is verified by the simulation and measured results of a scale model (1/10). Then, high-speed train-orbit coupling dynamics model is established and the force acting on the box girder structure is calculated, and applied as the load boundary condition to the box girder finite element model (FEM) to calculate the vibration response. Finally, vibration response as the acoustic boundary conditions, the indirect boundary element method (IBEM）is used to analyze the influence of the support stiffness on the sound radiation of the box girder. the result show that, In 3 different stiffness conditions, effects of beam sound power mainly concentrated in 1 ~ 48Hz, the greater the rigidity of the support, the smaller the acoustic power radiation value and the peak value. The maximum sound pressure level of the box girder is mainly concentrated in 1 ~20 Hz. The sound pressure level changes at each field are closer to the sound power change trend;The sound pressure levels of the three supports at the same field point are relatively close, but the greater the support stiffness, the smaller the sound pressure level; at the same field point, the greater the support stiffness, the smaller the peak value of the sound pressure level. In 48 ~ 100Hz, the stiffness value has little effect on the field SPL and the acoustic radiation of the beam。