Experimental investigation of sound absorption in a composite absorber

• 作者: Nansha Gao Hong Hou
• 来源期刊: 力学快报（英文版）
• 年，卷（期）: 2021,（1）
• 页码范围: 58-62
• 页数: 5页
• 语种: 英文
• DOI: 10.3969/j.issn.2095-0349.2021.01.011

摘要

A composite absorber made of a polyurethane sponge and multi-layer micro-perforated plates is pre- sented in this study. Results from an acoustic impedance tube test show that the polyurethane sponge can exhibits higher low-frequency sound absorption in front of the micro-perforated plate, while sound absorption at medium and high-frequencies remains low. The physical mechanism behind this is that the micro-perforated plate increases the denpth cavity. If the polyurethane sponge is placed behind the micro-perforated plate, the amplitude of the original absorption peak will remain constant, but the ab- sorption peaks will shift to lower frequencies. The reason for this phenomenon is that porous materials with low flow resistance can be approximately equivalent to fluid, which not only does not affect the res- onance absorption coefficient of micro-perforated plate, but also makes the peaks move to low frequency. This study has the potential applications in the sound absorption design of composite structure.