降噪块对嵌入式轨道声振特性和造价的影响

为了控制嵌入式轨道造价，工程中拟采用降噪块部分替代高分子阻尼填充材料或PVC管，为此需了解降噪块对嵌入式轨道声振特性和造价的影响。首先，本文基于有限元-边界元法建立了嵌入式轨道振动声辐射预测模型，并结合相关材料的造价，分析了降噪块替换部分浇注料对嵌入式轨道声振特性和造价的影响；其次，调查了使用降噪块替换PVC管对嵌入式轨道声振特性和造价的影响；最后，在前文调查结果的基础上，进一步优化降噪块的弹性模量，使得嵌入式轨道的声辐射性能与造价之比最优。相关结论如下：相比于无降噪块嵌入式轨道，双降噪块轨道造价降低了约3456元/米，辐射噪声仅增加约0.22dBA，性价比最佳；采用降噪块替换PVC管后，该轨道造价增加了约1409元/米，但辐射噪声仅降低约0.66dBA，性价比降低；在本文探讨的降噪块弹性模量范围内，降噪块材料弹性模量取10MPa时，轨道性价比最佳。

Influences of the Noise Reduction Blocks on Acoustic Radiation Performance and Cost of Embedded Tracks

In order to control the cost of embedded track, the noise reduction block is considered as a replacement part of the polymer damping material or PVC tubes. Therefore, it is necessary to research the influences of the noise reduction block on the vibration characteristics and the cost of embedded track. Firstly, the vibration and sound radiation prediction model of embedded track has been developed based on finite-boundary element method. In the model the castable material is partly replaced by the noise reduction block and its effect on sound radiation property and cost of the embedded track are analyzed when taking the specific cost of related materials into consideration. Secondly, the acoustic radiation characteristic and the cost of the embedded track whose PVC tubes are fully replaced by the noise reduction material are researched. Finally, in order to optimize the radiation effect and cost of the structure, the elastic modulus of the noise reduction block is further optimized. The conclusions are as follows: Compare with the track without noise block track, the track with double reduction blocks’ cost reduces up to about 3456 yuan/m and the noise increase only by nearly 0.22dBA, it has the best cost performance. After the PVC tubes have been replaced by noise reduction blocks, the cost of track increased about 1409 yuan/m and the noise decreased only by nearly 0.66dBA, the cost performance of track decreased. Within the research rang of the elastic modulus studied, when the elastic modulus of noise reduction block is 10MPa the Embedded Tracks reached the best cost performance.