高速铁路宽带复合吸声结构设计

针对高速铁路车外噪声频带宽的特征,设计了一种第1层为铝纤维板、第2层为铝微穿孔板的新型复合吸声结构。通过理论研究和试验测试优化调整其结构参数,利用多模态耦合获得了与以往的共振吸声结构相比更宽频带的高吸声性能。经测试,该结构总厚度为100 mm时,吸声系数在250~5000 Hz频段均不小于0.8,降噪系数为0.92,可覆盖高速铁路环境噪声的主要频率成分;总厚度继续增大,低频吸声系数和降噪系数可进一步提高。所设计的宽带复合吸声结构不仅吸声性能佳,选用的材料还具有良好的耐候性和物理、化学性能,绿色、环保、可回收利用。将其应用于我国高速铁路噪声控制工程,有助于推动我国绿色铁路建设。

Design of Broadband Composite Sound Absorption Structure for High Speed Railway

According to the characteristics of broadband of noise outside the high speed railway vehicle,a new composite sound-absorbing structure was designed,in which the first layer is aluminum fiberboard and the second layer is aluminum micro-perforated panel.Through the theoretical research and experimental test,the structural parameters were optimized and adjusted,and the high sound absorption performance with a broader bandwidth,which is compared with the previous resonance sound absorption structure,was obtained by using the multi-modal coupling.The test results show that when the total thickness of the structure is 100 mm,the sound absorption coefficient is not less than 0.8 in the frequency band of 250~5000 Hz,and the noise reduction coefficient is 0.92,which can cover the main frequency components of environmental noise of high-speed railway,as the total thickness continues to increase,the low-frequency sound absorption coefficient and noise reduction coefficient can be further improved.The designed broadband composite sound absorption structure not only has good sound absorption performance,but also has good weather resistance,physical and chemical properties,green environmental protection and is recyclable.It is helpful to promote the construction of green railway by applying this structure to the noise control engineering of high-speed railway in China.