Enhanced Acoustic Black Hole effect in beams with a modified thickness profile and extended platform
Enhanced Acoustic Black Hole effect in beams with a modified thickness profile and extended platform
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通过修改厚度剖面和扩展平台增强梁中的声学黑洞效应
DOI：
10.1016/j.jsv.2016.11.010
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发表时间：
2017-03
影响因子：
4.7
通讯作者：
Cheng Li
中科院分区：
文献类型：
--
作者：
Tang Liling;Cheng Li
声学黑洞(ABH)现象得益于厚度呈幂函数变化的薄壁结构中弯曲波的传播特性，在理想情况下，当结构厚度趋于零时，可以实现零反射。然而，在实践中很难制造出具有嵌入ABH特征的结构的理想定制的幂规律轮廓。过去的研究表明，结构楔形尖端不可避免的截断会产生波浪反射，从而显著削弱预期的ABH效应。在现有制造技术所能达到的最小截断厚度的前提下，探索如何保证和达到更好的ABH效果就显得尤为重要。在这篇文章中，我们利用先前发展的小波分解半解析模型，研究了具有修正的幂函数分布和扩展的等厚度平台的Euler-Bernoulli梁。通过与传统的ABH剖面在系统损耗因子和能量分布方面的比较，数值结果表明，改进的厚度剖面使ABH效应在中高频下有系统地增加，特别是当截断厚度较小时，剖面参数较大时。扩展平台的使用进一步增加了ABH效应，使频带更宽，同时为特定的低频应用提供了房间。
The phenomenon of Acoustics Black Hole (ABH) benefits from the bending wave propagating properties inside a thin-walled structure with power-law thickness variation to achieve zero reflection when the structural thickness approaches zero in the ideal scenario. However, manufacturing an ideally tailored power-law profile of a structure with embedded ABH feature can hardly be achieved in practice. Past research showed that the inevitable truncation at the wedge tip of the structure can significantly weaken the expected ABH effect by creating wave reflections. On the premise of the minimum achievable truncation thickness by the current manufacturing technology, exploring ways to ensure and achieve better ABH effect becomes important. In this paper, we investigate this issue by using a previously developed wavelet-decomposed semi-analytical model on an Euler-Bernoulli beam with a modified power-law profile and an extended platform of constant thickness. Through comparisons with the conventional ABH profile in terms of system loss factor and energy distribution, numerical results show that the modified thickness profile brings about a systematic increase in the ABH effect at mid-to-high frequencies, especially when the truncation thickness is small and the profile parametermis large. The use of an extended platform further increases the ABH effect to broader the frequency band whilst providing rooms for catering particular low frequency applications.
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DOI：
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发表时间：
--
期刊：
--
影响因子：
--
作者：
L.
通讯作者：
L.
影响因子：
4.7
作者：
Georgiev, V. B.;Cuenca, J.;Krylov, V. V.
通讯作者：
Krylov, V. V.
DOI：
--
发表时间：
1990
期刊：
--
影响因子：
--
作者：
V. Krylov
通讯作者：
V. Krylov
影响因子：
3.4
作者：
E. Bowyer;D. O'Boy;V. Krylov;F. Gautier
通讯作者：
E. Bowyer;D. O'Boy;V. Krylov;F. Gautier
有限尺寸结构中声学黑洞效应的损失
影响因子：
4
作者：
Tang Liling;Cheng Li
通讯作者：
Cheng Li