微穿孔型材结构隔声特性分析及影响因素探究

Analysis of Sound Insulation Characteristics of Microperforated Profile Structure and Investigation of Influencing Factors

针对高速列车型材中低频隔声,探究了平面波激励下,在型材上面板穿孔、筋板穿孔以及上面板和筋板同时穿孔时的传声损失。基于有限元法,在COMSOL中建立了微穿孔型材有限元模型,并考虑模型声学结构的相互作用以及穿孔后的孔内黏热损耗。通过与文献结果对比,验证了建模方法和仿真模型的准确性。与未穿孔型材相比,在型材上面板穿孔以及上面板和筋板同时穿孔均在其共振频率处产生共振峰值,具有更好的隔声特性。探讨了穿孔半径、穿孔率以及穿孔面板厚度对型材隔声特性的影响。结果表明:型材共振频率随着孔径的减小和穿孔率的增加而逐渐向高频移动;随着板厚的增加,型材共振频率逐渐向低频移动。在上面板和筋板同时穿孔比仅在上面板穿孔具有更低的共振频率。

Focusing on the mid to low-frequency sound insulation of high-speed train profiles,the sound transmission loss under plane wave excitation when the upper panel,the stiffener are perforated separately and when both the upper panel and the stiffener simultaneously is investigated.Based on the finite element method,the finite element model of the micro-perforated profile is established in COMSOL,and the interaction of the acoustic structure and the internal viscosity heat loss after perforation are considered.The accuracy of the modeling method and simulation model is verified by comparing with the literature results.Compared with the unperforated profile,the perforation on the upper panel and the simultaneous perforation on both the upper panel and the stiffener both result in resonance peaks at the resonance frequencies,which has better sound insulation characteristics.The influences of perforation radius,perforation rate and perforation panel thickness on sound insulation characteristics of profiles are discussed.The results show that the resonance frequency of profiles gradually shifts to high frequency with the decrease of aperture and the increase of perforation rate,and the resonance frequency of profiles gradually shifts to low frequency with the increase of plate thickness.Perforation on both the upper panel and the stiffener has a lower resonant frequency than only on the upper panel.