Full metadata record
| DC Field | Value | Language |
|---|---|---|
| dc.contributor | Faculty of Engineering | en_US |
| dc.contributor.advisor | Cheng, Li (ME) | - |
| dc.creator | Zhou, Tong | - |
| dc.identifier.uri | https://theses.lib.polyu.edu.hk/handle/200/9071 | - |
| dc.language | English | en_US |
| dc.publisher | Hong Kong Polytechnic University | - |
| dc.rights | All rights reserved | en_US |
| dc.title | Vibration control utilizing 'acoustic black hole' effect | en_US |
| dcterms.abstract | The ‘Acoustic Black Hole’ (ABH) effect can be exploited for flexural vibration suppressions in thin-walled structures. Conventional ABH structures, however, are tied with the inherent structural weakness due the low local stiffness required and possibly high stress concentration caused by the small residual thickness of the ABH taper, thus limiting their practical applications. In this thesis, the dynamic and static properties of an embedded double-layered compound ABH beam are investigated through numerical simulations. It is shown that, whilst ensuring effective ABH effect, the compound ABH structure allows a significant improvement in the static properties of the structure. For the former, the compound design is shown to outperform its counterpart in the conventional ABH configuration in terms of damping enhancement and vibration suppression. For the latter, the compound ABH structure is also shown to provide much better static properties in terms of structural stiffness and strength. Furthermore, the structural damping can be further improved by using an extended platform at the tip of power-law profile, which meanwhile improves the structural strength but reduces the structural stiffness. Therefore, when choosing the platform length, a balance needs to be struck among the desired ABH effect and the mechanical properties of the structure. Experimental measurement was also conducted to confirm the validity of the FEM analyses as well as the superior ABH effect of the compound ABH beams. To further improve the static and dynamic properties, compound ABH beams with an enlarged width are also investigated by numerical simulations. | en_US |
| dcterms.extent | 75 pages : color illustrations | en_US |
| dcterms.isPartOf | PolyU Electronic Theses | en_US |
| dcterms.issued | 2017 | en_US |
| dcterms.educationalLevel | M.Sc. | en_US |
| dcterms.educationalLevel | All Master | en_US |
| dcterms.LCSH | Hong Kong Polytechnic University -- Dissertations | en_US |
| dcterms.LCSH | Vibration -- Control | en_US |
| dcterms.LCSH | Structural dynamics | en_US |
| dcterms.accessRights | restricted access | en_US |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| 991021962224303411.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 2.78 MB | Adobe PDF | View/Open |
Copyright Undertaking
As a bona fide Library user, I declare that:
- I will abide by the rules and legal ordinances governing copyright regarding the use of the Database.
- I will use the Database for the purpose of my research or private study only and not for circulation or further reproduction or any other purpose.
- I agree to indemnify and hold the University harmless from and against any loss, damage, cost, liability or expenses arising from copyright infringement or unauthorized usage.
By downloading any item(s) listed above, you acknowledge that you have read and understood the copyright undertaking as stated above, and agree to be bound by all of its terms.
Please use this identifier to cite or link to this item:
https://theses.lib.polyu.edu.hk/handle/200/9071