障板與多孔材組合之隔音性能研究

Sound Insulation Characteristics of Panels Lined with Porous Material

The approach for the sound insulation of panel lined with porous materials has been developed. Biot theory is adopted for the analysis of the waves propagated in porous material. The transfer matrix between the contact interfaces and also between the two ends of the porous material and of the solid material has been established. The combination of these matrices can be conducted on evaluating the sound propagation characteristic in the layered media. The comparison of the transmission loss with the experimental measurements and results of the literature shows that the present method is reliable. The analysis of the double panels and sandwich panel reveals that the unbonded connection of the layer medium has better sound insulation ability in higher frequency range and just a little reduction in low frequency region. For double panels and sandwich panel, either bonded or unbonded, the increasing of the thickness of the porous material can improve the overall sound transmission loss is definite even though it is not so obvious in bonded case. 本文旨在探討板材與多孔吸音材組合時之隔音效果。文中採用Biot的理論分析在多孔材中之波傳現象，同時建立聲波在多孔材、彈性固體兩端或多孔材與彈性固體交界面之傳輸矩陣，並利用矩陣組合之方式來探討聲波在疊層材質中之傳播特性。文中首先以實驗量測以及與文獻結果之比較，驗證本文分析方法之正確性。在兩層材質或三明治材質之分析中可發現，層與層間不作接合，則在高頻區域有明顯的隔音效果提高現象，但低頻區隔音性能則有些微下降。另外，若增加多孔材之厚度，則不論層與層間接合或不接合，整體穿透損失皆有所改善，雖然在接合之情況下並不特別明顯。