Abstract Nowadays the use of porous polyurethane sponge (PPS) is very common for sound absorption, thanks to its light-weight feature and easy fabrication. However, in many circumstances the traditional PPS has very limited absorption capabilities, due to the slow wave phenomenon and/or to insufficient sub-wavelength sound absorption. In this paper, we propose a composite porous metamaterial (CPM) consisting in a porous polyurethane sponge with embedded multi-layer I-plates to mitigate this problem. To characterize the sound absorption coefficient of the proposed CPM, we resort to the Johnson-Champoux-Allard (JCA) model, where five acoustic parameters, namely porosity, flow resistivity, tortuosity, viscous, and thermal characteristic lengths, are determined by acoustic test methods. Numerical and experimental results show that the sound absorption performance of PPS in the CPM is remarkably improved, compared to a contrast structure and a pure porous material, taking advantage of a twofold mechanism of local acoustic energy dissipation of the I-plates and the slow wave phenomenon cancellation inside the structure. Finally, the effects of the geometrical parameters on average sound absorption coefficient are presented and discussed in detail. The scheme of this paper possesses potential application value for the design of broadband and efficient sound absorbers, providing a reference for researches of new acoustic functional devices with high absorption performances.

中文翻译：

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I型板嵌入多孔聚氨酯海绵复合多孔超材料的设计、制作及吸声试验

摘要 如今，多孔聚氨酯海绵 (PPS) 因其重量轻且易于制造而被广泛用于吸音。然而，在许多情况下，由于慢波现象和/或亚波长吸声不足，传统PPS的吸收能力非常有限。在本文中，我们提出了一种复合多孔超材料（CPM），由多孔聚氨酯海绵和嵌入的多层 I 板组成，以缓解这个问题。为了表征所提出的 CPM 的吸声系数，我们采用 Johnson-Champoux-Allard (JCA) 模型，其中五个声学参数，即孔隙度、流阻、曲折度、粘性和热特征长度，通过声学测试确定方法。数值和实验结果表明，与对比结构和纯多孔材料相比，PPS 在 CPM 中的吸声性能得到显着提高，利用 I 板局部声能耗散和慢波的双重机制。结构内部的现象消除。最后，详细介绍并讨论了几何参数对平均吸声系数的影响。本文的方案对于宽带高效吸声体的设计具有潜在的应用价值，为新型高吸声吸声功能器件的研究提供参考。利用 I 板局部声能耗散和结构内部慢波现象消除的双重机制。最后，详细介绍并讨论了几何参数对平均吸声系数的影响。本文的方案对于宽带高效吸声体的设计具有潜在的应用价值，为新型高吸声吸声功能器件的研究提供参考。利用 I 板局部声能耗散和结构内部慢波现象消除的双重机制。最后，详细介绍并讨论了几何参数对平均吸声系数的影响。本文的方案对于宽带高效吸声体的设计具有潜在的应用价值，为新型高吸声吸声功能器件的研究提供参考。