Periodicity-Enhanced Attenuating Layers and Structures
Lead Research Organisation:
University of Salford
Department Name: Sch of Computing, Science & Engineering
Abstract
Periodicity-enhanced (meta) materials and surfaces are artificial structures that possess properties not found in naturally-occurring materials and surfaces. The periodicity stems from the regular spacing of inclusions in a host matrix or roughness on a surface. Inclusions range from solid cylinders in air such as encountered in 'sonic crystals' to a grid framework in a poroelastic material such as an air-filled foam used for sound absorption. Roughness elements can be of various shapes and profiles ranging from identical rectangular grooves to arrays with fractal profiles. Without further modification, periodicity-enhanced materials stop the passage of some incident wavelengths (or frequencies) and enhance the transmission of others. By modifying the roughness of a surface, the interference between waves travelling directly from a source to a receiver above the surface and waves reflected from the surface can be controlled.
The proposal is concerned with ways of extending the frequency range over which the periodicity-enhanced materials and surfaces reduce the transmission of sound and vibration. The methods to be investigated include use of locally resonant inclusions or roughness elements, use of multiple resonances, exploitiation of interactions and overlaps between resonances periodicity-related transmission loss and spatial variation of periodicity and other characteristics thereby producing graded systems and roughness profiles. The work will provide a basis for the design of more efficient sound and vibration absorbing devices that are lightweight yet offer high transmission loss and vibration damping properties. The resulting surface designs will include alternatives to conventional noise barriers, while allowing access and preserving line of sight, and cost-effective methods for protecting buildings against ground-borne vibrations.
The proposal is concerned with ways of extending the frequency range over which the periodicity-enhanced materials and surfaces reduce the transmission of sound and vibration. The methods to be investigated include use of locally resonant inclusions or roughness elements, use of multiple resonances, exploitiation of interactions and overlaps between resonances periodicity-related transmission loss and spatial variation of periodicity and other characteristics thereby producing graded systems and roughness profiles. The work will provide a basis for the design of more efficient sound and vibration absorbing devices that are lightweight yet offer high transmission loss and vibration damping properties. The resulting surface designs will include alternatives to conventional noise barriers, while allowing access and preserving line of sight, and cost-effective methods for protecting buildings against ground-borne vibrations.
People |
ORCID iD |
| Olga Umnova (Principal Investigator) |
Publications
Schwan L
(2017)
Sound absorption and reflection from a resonant metasurface: Homogenisation model with experimental validation
in Wave Motion
| Description | We have discovered that 1. A method of multi-scale homogenization can be used to derive a simple expression for the admittance of a resonant metasurface. At the leading order, this is described by a simple analytical expression, while at the corrector order a non-local nature of admittance has to be accounted for. 2. A total absorption of incident sound can be achieved with a finite size metasurface around the resonance frequency of the unit cells. The phenomena are quite robust and good absorption is achieved even when the incident wave is not plane. 3. Mixing slightly mistuned resonators in a single cell broadens the frequency range where high absorption values are achieved. The interaction between the resonators can be described as a part of the homogenization procedure. 4. We have shown that graded surfaces, certain surfaces with several resonators per period and corrugated 5. It has been demonstrated numerically and experimentally that the metasurface is efficient for cavity mode control. 6. Another part of work has been devoted to the interaction of resonators in a single unit of a metamaterial and the interaction between the resonators and the substrate. It has been shown that the resonance frequency can be controlled by rotating the resonators. The lowest frequency is achieved when the slots are facing each other or when the slot is facing the substrate. 7. Effective boundary conditions become non-local when surface properties are graded and when the surface is corrugated. In these cases, the non-locality appears in the corrector order derivations over the smallness parameter identified as the ratio of lattice constant to the wavelength at resonance. |
| Exploitation Route | We expect, the results will attract an interest from the research community. We expect that the method of multi-scale homogenization will find a wide application for modelling properties of metasurfaces and metamaterials. This should include the cases when the contrast between the scales is not high, so accounting for corrector order terms in the homogenization procedure becomes necessary. The model developed can be used as a design tool for building metasurfaces with prescribed acoustic properties. |
| Sectors | Aerospace, Defence and Marine,Construction,Transport,Other |
| URL | http://www.sciencedirect.com/science/article/pii/S0165212517300161 |
| Description | The findings of this project have been already used for 3 BSc, 1MSc and 1 MRes projects at the University of Salford. A collaboration with the industry (Carbon Air Ltd, DSTL UK) is developing -the elements of metasurface design and modelling will be used for the development of new structures/ products. A KTP project with Cosmotec Textiles (funded by Innovate UK) has been successfully completed in 2019. The work on developing new product ideas was based on the findings of Periodicity Enhanced Attenuating Layers and Structures project. In particular, near field interactions between the fibres within the nonwoven materials have been used to enhance their sound absorption capacity. |
| First Year Of Impact | 2016 |
| Sector | Aerospace, Defence and Marine,Digital/Communication/Information Technologies (including Software),Education,Manufacturing, including Industrial Biotechology,Transport |
| Impact Types | Economic |
| Description | Vice-chair and member of the COST Action DENORMS CA 15125 |
| Geographic Reach | Europe |
| Policy Influence Type | Influenced training of practitioners or researchers |
| Impact | COST Action DENORMS CA 15125 |
| URL | https://denorms.eu/ |
| Description | DSTL-DGA Anglo-French PhD studentship, project title "Acoustic metamaterials for harsh environments" |
| Amount | £128,849 (GEL) |
| Organisation | Defence Science & Technology Laboratory (DSTL) |
| Sector | Public |
| Country | United Kingdom |
| Start | 09/2017 |
| End | 04/2019 |
| Description | Poroelastic metasurface for simultaneous attenuation of airborne sound and vibrations |
| Amount | £52,000 (GBP) |
| Organisation | University of Salford |
| Sector | Academic/University |
| Country | United Kingdom |
| Start | 09/2019 |
| End | 10/2022 |
| Description | Senior Visiting Researcher, University of Burgundy |
| Amount | € 4,000 (EUR) |
| Organisation | University of Burgundy |
| Sector | Academic/University |
| Country | France |
| Start | 05/2014 |
| End | 07/2014 |
| Description | Visiting researcher grant, University of Burgundy, France |
| Amount | € 6,000 (EUR) |
| Organisation | University of Burgundy |
| Sector | Academic/University |
| Country | France |
| Start | 05/2018 |
| End | 08/2018 |
| Title | Measurement data on absorption of metasurface in anechoic environment |
| Description | Measurement data on the performance of resonance metasurface in anechoic environment collected at Salford University in November - December 2015. |
| Type Of Material | Database/Collection of data |
| Provided To Others? | No |
| Impact | The data generated confirm that full absorption at resonance frequency can be achieved by a finite size metasurface even when the incident wave is not plane |
| Title | measurement data on the performance of metasurface in the impedance tube |
| Description | The experiments have been performed at Salford University confirming the design approach to achieve the full absorption at resonance frequency and in the frequency band centred at it. the experiments have been performed using Salford University impedance tube. |
| Type Of Material | Database/Collection of data |
| Provided To Others? | No |
| Impact | The design approach developed by the group has been confirmed by the measurements performed using impedance tube. This is the simplest and most controlled environment for acoustic experiments. The measurements have been performed on a number of identical basic elements of the metasurface as well as a mixture of elements with different resonance frequencies. A very good agreement with the model has been observed. |
| Description | C. Boutin ENTPE, France, |
| Organisation | University of Lyon |
| Department | National School of Public Works of the State |
| Country | France |
| Sector | Academic/University |
| PI Contribution | Contribution to collaboration from Salford: Multiple scattering, Experiments, development of homogenization technique in application to acoustic metasurfaces |
| Collaborator Contribution | Contribution to collaboration from ENTPE: Two -scale asymptotic homogenization technique |
| Impact | Several papers listed in the Publications section have been written in collaboration with C.Boutin |
| Start Year | 2014 |
| Description | DSTL |
| Organisation | Defence Science & Technology Laboratory (DSTL) |
| Country | United Kingdom |
| Sector | Public |
| PI Contribution | The models and the devices/ structures developed during the project |
| Collaborator Contribution | Testing facilities, advice on the use of the project outcomes for military applications |
| Impact | The collaboration is still in its early stage so there are no any particular outcomes yet |
| Start Year | 2014 |
| Description | University of Burgundy, France |
| Organisation | University of Burgundy |
| Country | France |
| Sector | Academic/University |
| PI Contribution | An analytical model has been developed by O.U. for a joint paper published in Journal of the Acoustical Society of America in October 2015 |
| Collaborator Contribution | A numerical model and experiments for this paper have been performed by research team in ISAT, University of Burgundy, France |
| Impact | A joint paper has been submitted to Journal of the Acoustical Society of America A joint PhD project with ISAT has started in October 2016 |
| Start Year | 2014 |
| Description | collaboration with LAUM, University of Maine, France |
| Organisation | University of Maine |
| Country | United States |
| Sector | Academic/University |
| PI Contribution | Analytical models edeveloped by O.U. have been published in two joint papers. O.U. lead a submission of COST proposal in 2013 (unsuccessful), which was prepared in collaboration with research team from LAUM. |
| Collaborator Contribution | Numerical models. COST proposal has been prepared jointly. |
| Impact | Two joint research papers published in 2013. COST grant proposal in 2014 (unsuccessful). |
| Start Year | 2012 |
| Description | COST Action DENORMS CA 15 25 workshop |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Postgraduate students |
| Results and Impact | Logan Schwan and Olga Umnova are engaged with COST Action DENORMS CA 15 25 project: O.U. as a co-chair and L.S. as a regular member. They participated in the 1st DENORMS workshop held in Jan 2017 in Rome. The audience mostly comprised of PhD students, early career researchers and industrial partners. |
| Year(s) Of Engagement Activity | 2017 |
| URL | https://denorms.eu/2016/09/28/workshop/ |
| Description | paper in a professional magazine |
| Form Of Engagement Activity | A magazine, newsletter or online publication |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Industry/Business |
| Results and Impact | A paper is published in Issue 82, 2016 of La revue Acoustique & Techniques, entitled Contrôle des vibrations par surfaces résonantes : Exemples en acoustique et en élastodynamique by L.Schwan, C.Boutin, O.Umnova and M.Dietz. |
| Year(s) Of Engagement Activity | 2016 |