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Applications of Multiple Resonators ...

Au-yeung, Ka Yan.

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Applications of Multiple Resonators for Noise Reduction and Mechanical Vibration Damping.

Record Type:	Electronic resources : Monograph/item
Title/Author:	Applications of Multiple Resonators for Noise Reduction and Mechanical Vibration Damping./
Author:	Au-yeung, Ka Yan.
Published:	Ann Arbor : ProQuest Dissertations & Theses, : 2021,
Description:	138 p.
Notes:	Source: Dissertations Abstracts International, Volume: 83-01, Section: B.
Contained By:	Dissertations Abstracts International83-01B.
Subject:	Materials science. -
Online resource:	https://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=28697806
ISBN:	9798534657678

Applications of Multiple Resonators for Noise Reduction and Mechanical Vibration Damping.
Au-yeung, Ka Yan.

Applications of Multiple Resonators for Noise Reduction and Mechanical Vibration Damping. - Ann Arbor : ProQuest Dissertations & Theses, 2021 - 138 p.

Source: Dissertations Abstracts International, Volume: 83-01, Section: B.

Thesis (Ph.D.)--Hong Kong University of Science and Technology (Hong Kong), 2021.

This item must not be sold to any third party vendors.

Low frequency noise absorption and vibration damping has been a challenge in everyday life, compromising the quality of life and health especially for urban dwellers. A small, reliable, effective passive noise absorption and damping system that is easy to install and maintain at low-cost is needed. In this research, two kinds of acoustic metamaterials were researched to see if they have the properties necessary to develop such a system. Acoustics metamaterials were well-proved effective low-frequency noise absorbers. Two types of acoustics metamaterials, split tube resonators and membrane-type acoustic metamaterial (MAMM), were investigated here. A split tube resonators is a box consists of two narrow splits, two narrow channels and an air cavity. Friction is generated when air passes the resonators. This feature leads to absorption of sound. Two split tube resonators can form a unit of ventilated metamaterial absorber (VMA). Using two layers of VMA could reach almost perfect absorption at < 500 Hz in experiments and simulations. MAMM consists of an elastic membrane with a locally decorated pattern mounted on a rigid frame. Perfect absorption at multiple frequencies could be demonstrated in experiments and simulations in 200 − 1000 Hz using an asymmetric resonator. Next, MAMM could be used as a tuned mass damper in the damping system. The damping parameters, frequency and quality factor can be tuned easily and studied by the effective mass method. Multiple frequency dampers and multiple dampers with different frequencies were studied. The damping effect on primary resonance on a beam and plate with free boundaries could be lowered by 20dB using MAMM as tuned mass dampers. The coherent super decay phenomenon was discovered when multiple dampers were applied to a structure. It is a linear sum of the displacement of several damped oscillators that can collectively decay much faster than the individual ones. The concept of coherent super decay was introduced and applied in a simulation of a 10-storey building. This simulation was done easily by using the effective mass methodology. The maximum displacement of the building was lowered by 39.9% with 100 dampers whose total mass was only 1.8% of the whole building.

ISBN: 9798534657678Subjects--Topical Terms:

543314
Materials science.
Subjects--Index Terms:

Acoustic metamaterials

Applications of Multiple Resonators for Noise Reduction and Mechanical Vibration Damping.
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260 1 $a Ann Arbor : $b ProQuest Dissertations & Theses, $c 2021
300 $a 138 p.
500 $a Source: Dissertations Abstracts International, Volume: 83-01, Section: B.
500 $a Advisor: Yang, Zhi Yu.
502 $a Thesis (Ph.D.)--Hong Kong University of Science and Technology (Hong Kong), 2021.
506 $a This item must not be sold to any third party vendors.
520 $a Low frequency noise absorption and vibration damping has been a challenge in everyday life, compromising the quality of life and health especially for urban dwellers. A small, reliable, effective passive noise absorption and damping system that is easy to install and maintain at low-cost is needed. In this research, two kinds of acoustic metamaterials were researched to see if they have the properties necessary to develop such a system. Acoustics metamaterials were well-proved effective low-frequency noise absorbers. Two types of acoustics metamaterials, split tube resonators and membrane-type acoustic metamaterial (MAMM), were investigated here. A split tube resonators is a box consists of two narrow splits, two narrow channels and an air cavity. Friction is generated when air passes the resonators. This feature leads to absorption of sound. Two split tube resonators can form a unit of ventilated metamaterial absorber (VMA). Using two layers of VMA could reach almost perfect absorption at < 500 Hz in experiments and simulations. MAMM consists of an elastic membrane with a locally decorated pattern mounted on a rigid frame. Perfect absorption at multiple frequencies could be demonstrated in experiments and simulations in 200 − 1000 Hz using an asymmetric resonator. Next, MAMM could be used as a tuned mass damper in the damping system. The damping parameters, frequency and quality factor can be tuned easily and studied by the effective mass method. Multiple frequency dampers and multiple dampers with different frequencies were studied. The damping effect on primary resonance on a beam and plate with free boundaries could be lowered by 20dB using MAMM as tuned mass dampers. The coherent super decay phenomenon was discovered when multiple dampers were applied to a structure. It is a linear sum of the displacement of several damped oscillators that can collectively decay much faster than the individual ones. The concept of coherent super decay was introduced and applied in a simulation of a 10-storey building. This simulation was done easily by using the effective mass methodology. The maximum displacement of the building was lowered by 39.9% with 100 dampers whose total mass was only 1.8% of the whole building.
590 $a School code: 1223.
650 4 $a Materials science. $3 543314
650 4 $a Acoustics. $3 879105
650 4 $a Mechanical engineering. $3 649730
650 4 $a Quality of life. $3 529789
650 4 $a Simulation. $3 644748
650 4 $a Construction. $3 3561054
650 4 $a Fourier transforms. $3 3545926
650 4 $a Sound waves. $3 3561055
650 4 $a Experiments. $3 525909
650 4 $a Permeability. $3 915594
650 4 $a Earthquakes. $3 535233
650 4 $a Seismic engineering. $3 3561056
650 4 $a Building failures. $3 773020
650 4 $a Noise control. $3 658942
650 4 $a Vibration. $3 544256
653 $a Acoustic metamaterials
653 $a Vibration damping
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690 $a 0548
690 $a 0986
710 2 $a Hong Kong University of Science and Technology (Hong Kong). $3 1022235
773 0 $t Dissertations Abstracts International $g 83-01B.
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792 $a 2021
793 $a English
856 4 0 $u https://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=28697806