A parametric study and modal analysis of an acoustic black hole on a beam
A parametric study and modal analysis of an acoustic black hole on a beam
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发表时间：
2018-09
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通讯作者：
K. Hook;J. Cheer;S. Daley
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作者：
K. Hook;J. Cheer;S. Daley
声学黑洞是一种具有不同厚度轮廓的结构特征，为弯曲振动提供了一种潜在的轻量级阻尼解决方案。在实际应用中，声黑洞的长度将受到可用空间的限制，最小尖端高度将受到制造能力和强度要求的限制。因此，锥度的幂律往往是关键的设计参数。本文给出了一种具有实际约束条件的声黑洞端点在光束上的参数化研究。计算了一个幂律范围内声黑洞的反射系数，结果表明，对于一个固定的幂律，反射系数随频率变化，呈现出高反射带和低反射带。这些波段可能与声黑洞的模式有关。此外，还发现存在一个最优幂律，使每个声黑洞构型的宽带平均反射系数最小。
Acoustic black holes are structural features that have a varying thickness profile, and provide a potential lightweight damping solution for flexural vibrations. In practical applications, the length of an acoustic black hole will be constrained by the available space and the minimum tip height will be limited by both the manufacturing capabilities and strength requirements. Therefore, the power law of the taper is often the critical design parameter. In this paper, a parametric study of an acoustic black hole termination on a beam is presented with practical constraints on the length and tip height. The reflection coefficient of the acoustic black hole has been calculated for a range of power laws and it has been shown that, for a fixed power law, the reflection coefficient varies over frequency and exhibits bands of high and low reflection. These bands can be related to modes of the acoustic black hole. In addition, it has been found that an optimum power law exists for minimising the broadband average reflection coefficient for each acoustic black hole configuration.