Conlon Stephen C, Feurtado Philip A
Applied Research Laboratory, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
J Acoust Soc Am. 2018 Feb;143(2):921. doi: 10.1121/1.5024235.
Acoustic black holes (ABHs) have been explored and demonstrated to be effective passive treatments for broadband noise and vibration control. Performance metrics for assessing damping concepts are often focused on maximizing structural damping loss factors. Optimally performing damping treatments can reduce the resonant response of a driven system well below the direct field response. This results in a finite structure whose vibration input-output response follows that of an infinite structure. The vibration mobility transfer functions between locations on a structure can be used to assess the structure's vibration response phase, and compare its phase response characteristics to those of idealized systems. This work experimentally explores the phase accumulation in finite plates, with and without embedded grids of ABHs. The measured results are compared and contrasted with theoretical results for finite and infinite uniform plates. Accumulated phase characteristics, their spatial dependence and limits, are examined for the plates and compared to theoretical estimates. The phase accumulation results show that the embedded acoustic black hole treatments can significantly enhance the damping of the plates to the point that their phase accumulation follows that of an infinite plate.
声学黑洞（ABHs）已被研究并证明是用于宽带噪声和振动控制的有效被动处理方法。评估阻尼概念的性能指标通常侧重于最大化结构阻尼损耗因子。性能最佳的阻尼处理可以将驱动系统的共振响应降低到远低于直接场响应的水平。这会产生一个有限结构，其振动输入输出响应与无限结构的响应相同。结构上不同位置之间的振动迁移率传递函数可用于评估结构的振动响应相位，并将其相位响应特性与理想化系统的特性进行比较。这项工作通过实验探索了有限平板在有和没有嵌入声学黑洞网格情况下的相位累积情况。将测量结果与有限和无限均匀平板的理论结果进行比较和对比。研究了平板的累积相位特性、它们的空间依赖性和极限，并与理论估计值进行比较。相位累积结果表明，嵌入的声学黑洞处理可以显著增强平板的阻尼，使其相位累积情况与无限平板的情况相同。
