A parametric study of an acoustic black hole on a beam
A parametric study of an acoustic black hole on a beam
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DOI：
10.1121/1.5111750
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发表时间：
2019-06-01
影响因子：
2.4
通讯作者：
Daley, S.
中科院分区：
文献类型：
--
作者：
Hook, K.;Cheer, J.;Daley, S.
声学黑洞（ABH）的几何结构特征，提供了一个潜在的轻量级的弯曲振动阻尼解决方案。在这篇文章中，一个ABH的梁上的参数研究已进行评估如何实际的设计约束影响其行为，从而提供了详细的了解设计权衡。ABH的反射系数已被计算为每个锥形轮廓，通过尖端高度，锥形长度和幂律参数化，它已被证明表现出低反射的光谱带。这些频带已经与ABH单元的模式相关，并且随着ABH参数的适当变化，这些频带在频率上变得更紧密地间隔开。这表明ABH设计应最大化模态密度以最小化宽带反射系数;然而，最小反射水平也取决于幂律和尖端高度。因此，宽带反射值已被用来表明，最佳的幂律和尖端高度设置存在，实现最大模态密度和最低水平的反射之间的平衡。此外，在离散频率下，在尖端高度和锥形长度实际上受到限制的情况下，可以调整幂律以最大化性能。最后，通过实验研究验证了结果。
Acoustic black holes (ABHs) are geometric structural features that provide a potential lightweight damping solution for flexural vibrations. In this article, a parametric study of an ABH on a beam has been carried out to assess how practical design constraints affect its behaviour, thus providing detailed insight into design trade-offs. The reflection coefficient of the ABH has been calculated for each taper profile, parameterised via the tip-height, taper-length, and power-law, and it has been shown to exhibit spectral bands of low reflection. These bands have been related to the modes of the ABH cell and become more closely spaced in frequency as the ABH parameters are suitably varied. This suggests that ABH design should maximise the modal density to minimise the broadband reflection coefficient; however, the minimum level of reflection is also dependent on the power-law and tip-height. Consequently, broadband reflection values have been used to show that optimum power-law and tip-height settings exist that achieve a balance between maximum modal density and minimum level of reflection. Additionally, at discrete frequencies, in cases where tip-height and taper-length are practically constrained, the power law can be tuned to maximise performance. Finally, an experimental study is used to validate the results.