Enhanced acoustic black hole effect using a modified thickness profile

Liling Tang, Li Cheng, Hongli Ji, Jinhao Qiu

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review

4 Citations (Scopus)

Abstract

The phenomenon of Acoustics Black Hole (ABH) takes place when bending waves propagate inside a think-walled structure with a power-law thickness profile. The phenomenon as well as its application potential in vibration damping enhancement, noise control and energy harvesting has also been demonstrated theoretically and experimentally by recent research. However, manufacturing an ideally tailored power-law profile can hardly be achieved in practice. The unavoidable truncation at the wedge tips of the structure can significantly weaken the ABH effect. On the premise of the minimum achievable truncation thickness by current manufacturing technology, ways to ensure and achieve better ABH effect need to be explored. In this paper, we investigate this issue using a previously developed wavelet-decomposed semi-analytical model on an Euler-Bernoulli beam with a modified power-law profile. As a continuation of the previous work, the model was first validated experimentally using a truncated conventional ABH profile. Then, the modified thickness profile is numerically investigated in terms of system loss factor and energy distribution. Compared with the conventional thickness profile with the same truncated wedge tip, it is shown that the modified thickness profile, along with the use of an extended plateau at the wedge tip, brings about a systematic increase in the ABH effect at mid-to-high frequencies, whilst providing rooms for possible low frequency applications.
Original languageEnglish
Title of host publicationProceedings of the INTER-NOISE 2016 - 45th International Congress and Exposition on Noise Control Engineering: Towards a Quieter Future
PublisherGerman Acoustical Society (DEGA)
Pages2361-2369
Number of pages9
Publication statusPublished - 21 Aug 2016
Event45th International Congress and Exposition on Noise Control Engineering: Towards a Quieter Future, INTER-NOISE 2016 - Hamburg, Germany
Duration: 21 Aug 201624 Aug 2016

Conference

Conference45th International Congress and Exposition on Noise Control Engineering: Towards a Quieter Future, INTER-NOISE 2016
Country/TerritoryGermany
CityHamburg
Period21/08/1624/08/16

Keywords

  • Acoustic Black Hole
  • Damping enhancement
  • Modified thickness profile

ASJC Scopus subject areas

  • Acoustics and Ultrasonics

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