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Workshop on “Modelling of high performance acoustic structures Porous media, metamaterials and sonic crystals”

DENORMS Action’s first Workshop entitled “Modelling of high performance acoustic structures Porous media, metamaterials and sonic crystals” will take place on 24th and 25th January 2017 in Rome, organised by Roma Tre University.

This first Workshop will be dedicated to theoretical and numerical modelling of acoustic treatments made of porous materials and periodic structures. The Workshop will also have a session on Multiphysics applications including electromagnetics. This session will be aimed at broadening the scope of theoretical and numerical results available in different areas of Physics and Mathematics. On this occasion, the leading experts in these fields will share their knowledge with other researchers, PhD students, young scientists and engineers from all across Europe.

Agenda

Tuesday 24th Jan.
Morning Session: New trends in traditional noise treatments – porous materials and microperforated plates

Opening Ceremony: 8h15-8h30

Plenary lecture: 08h30 – 09h15

Waves in porous materials
Keith Attenborough (The Open University), H.-C. Shin, I. Bashir, and S. Taherzadeh

Many observations of waves in porous materials are explained by Biot theory for dynamic poroelasticity. An important prediction of Biot theory is that, as well as a shear wave, there are two kinds of dilatational waves (i.e. a ‘fast’ and a ’slow’) that can propagate in a fluid-saturated poroelastic medium. ‘Slow’ waves are known to be important in determining the acoustical properties of air-saturated porous elastic solid materials with open connected pores since they are the most easily excited by fluid-borne excitation. There is considerable argument about the ability of Biot-type theories to explain the frequency-dependence of dilatational wave attenuation in underwater sediments in part because a viscous grain shearing theory is able to explain the observed frequency dependence of attenuation in underwater sediments without including a ‘slow’ wave. Direct evidence for the arrival of two distinct compressional wave types can be found in data for ultrasonic transmission through water-saturated bone and air-filled foam layers. Indirect evidence is provided by the results of measurements using separate acoustical- and mechanical-excitation of air-filled polyurethane foam. Biot-based predictions of the relative importance of the ‘fast’ and ‘slow’ waves in water- and air-saturated contexts are discussed. Also the effects of pore size distribution are explored in view of the facts that they are more important than pore shape effects and that parameters introduced by modifications to Biot theory due to Allard, Champoux, Lafarge and Pride can be related to parameters of the pore size distribution. A consequence of the two compressional waves in air-filled poroelastic layers is that two types of surface wave can be generated associated with the slow and shear waves respectively. The former is related to the surface wave created by a point source over a rough surface and the latter represents an air-coupled Rayleigh wave.

9h30-9h50: Nicolas Dauchez (Université de Technologie de Compiègne), Sound absorption of a poroelastic cuboid network

9h50-10h10: Venegas Rodolfo (ENTPE), Enhancing sound attenuation in multiscale porous materials via diffusion processes

10h10-10h30: Fabien Chevillotte (Matelys – Research Lab), From the microstructure to condensed equivalent fluid models

10h30-11h: Coffee Break

11h-11h20: Hugo Karpinski (University of Salford), Acoustical properties of nanoporous activated carbon felts

11h20-11h40: Tomasz Zielinski (Institute of Fundamental Technological Research of the Polish Academy of Sciences), Sound absorption of plates with micro-slits backed with an air cavity: analytical estimations, numerical modelling and measurements

11h40-12h: Mathieu Gaborit (KTH Royal Institute of Technology), Coupling of Bloch waves and Finite-Element models: case of metaporous sandwich structures

Afternoon session: Acoustic metamaterials (i.e. subwavelength absorbers), metasurfaces and sonic crystals for audible sound manipulation

Plenary lecture: 13h30-14h15

Subwavelength absorbers and metasurfaces
Noé Jiménez ( Laboratoire d’Acoustique de l’Université du Maine, UMR 6613 CNRS), J.-P. Groby, V. Romero-García, V. Pagneux, W. Huang (LAUM, UMR 6613 CNRS), and T. Cox (Univ. of Salford)

In the last decades, the exotic features of acoustic metamaterials have been deeply explored, but these special properties have been only recently extensively applied to audible sound in practical applications. The use of structured and locally-resonant media offers the possibility of tailoring their acoustic properties with a huge number of degrees of freedom (or with a huge freedom as you want), and, due to their resonant nature, their dimensions can be reduced to the subwavelength regime. This key feature has critical implications in the design of low frequency sound acoustic treatments, where the dimensions of the acoustic wavelength can exceed several meters. In this talk, different applications of structured materials with subwavelength dimensions are reviewed. First, we design absorbing panels for the reflection problems using arrays of Helmholtz resonators, showing that, using slow sound and the concept of critical coupling, perfect absorption can be obtained for panels almost one hundred thinner than the wavelength. Then, we show how using the same configuration, but allowing transmission, the problem of perfect absorption becomes more complex and we present several approaches to solve these issues. Solutions include transparent materials using the accumulation of resonances, symmetry-breaking and rainbow trapping metamaterials, where subwavelength perfect absorbers can be designed for a frequency band covering two octaves. Finally, we present the use of these resonant materials to tune the scattering of subwavelength thickness panels, showing the potential of structured materials for engineering acoustic applications in the audible regime.

14h30-14h50: Joong Seok Lee (Chungnam National University), Broadband sound absorption using multiple slow waves in metaporous layers

14h50-15h10: Ashwin Sridhar (Eindhoven University of Technology), A multiscale semi-analytical approach towards plane wave analysis of local resonance metamaterials

15h10-15h30: Neha Sharma (University of Salford), A Low Frequency Muffler based on the Acoustic Black Hole Effect

15h30-15h50: Coffee Break

15h50-16h10: Milan Cervenka (Czech Technical University in Prague), Acoustic bandpass filters employing shaped resonators

16h10-16h30: Bart Van Damme (Empa Switzerland), Theoretical and experimental investigation of bending waves in beams with a periodic structure

16h30-16h50: Logan Schwan (Laboratoire d’Acoustique de l’Université du Maine, UMR 6613 CNRS), Theory and experiments on surface acoustic waves at a lossy metasurface: complex dispersion relation and surface slow sound

17h-17h30: Round table (discussion on the presented topics and possible future developments within the WG1)

Wednesday 25th Jan.
Morning session New trends in vibroacoustics (i.e. elastic metamaterials and metasurfaces)

Plenary lecture: 8h30 – 9h15

Seismic Metamaterials
Richard Craster (Imperial College London), A. Colombi (Imperial College), D. Colquitt (Univ. of Liverpool), S. Guenneau, S. Enoch, S. Brule, Y. Achaoui (Univ. Marseille), P. Roux (ISTerre), and T. Antonakakis (Multiwave, Geneva)

It has been known for many years now that one can develop metamaterials in electromagnetism and, at least in theory, steer and manipulate waves in optics and electromagnetism; although in reality the various losses in real materials do limit the effectiveness. This is all at the nanoscale, elasticity and acoustics, on the other hand, are typically at far longer scales and the effect of losses can be less. I will consider two different models: one based on subwavelength resonators to generate mode conversion from surface to bulk waves which is truly a metamaterial and then I will introduce a seismic metamaterial based on periodic media with an ultra-low and wide bandgap that will stop very long waves from propagating, so subwavelength in some sense but not using resonators.

9h30-9h50: Lucas Pomot (Aix Marseille University), C. Payant, and S. Guenneau, Combining transformation physics and homogenization for designs of seismic cloaks

9h50-10h10: Aleksey Pichugin (Brunel University London), Asymptotic modelling of the Rayleigh-Bloch waves travelling along a periodically-perturbed elastic surface

10h10-10h30: Ioannis Antoniadis (National technical Univeristy of Athens), Towards the design of highly dissipative low-frequency metamaterials: the k-damping concept

10h30-11h: Coffee Break

11h-11h20: Claude Boutin (ENTPE /CNRS Université de Lyon), P. Fossat, and K. Viverge, On the non-conventional vibro-acoustic behaviour of highly contrasted plates

11h20-11h40: Anastasiia Krushynska (University of Turin), Spider web-inspired acoustic metamaterials for sound manipulation

11h40-12h: Lucas Van Belle (KU Leuven), Modelling, analysis and experimental validation of vibro-acoustic locally resonant metamaterials including damping

12h-12h20: Sakdirat Kaewunruen (University of Birmingham), Engineered crumbed rubber concrete for vibroacoustic reduction in railway built environment

Afternoon session: Use of metamaterials in other fields of Physics and metamaterials exposed to multiple physical phenomena

Plenary lecture: 13h30-14h15

Numerical modelling of metamaterials: electromagnetic and acoustic applications
Alessandro Toscano (Roma Tre University)

With the term « metamaterials » (MTM) we refer to the wide family of artificially engineered electromagnetic materials and, thus, not existing in the nature, designed through the intrusion of given inclusions with proper shape and dimensions in a host medium. The surprising features of metamaterials, their easy large-scale realization, and the results obtained by several different groups both at the European and worldwide level, allow nowadays to employ metamaterials as a suitable solution to overcome the traditional limits of current devices realized with conventional materials. In this talk the last results obtained at Roma Tre on possible, practical applications of metamaterials in acoustics, microwaves and optics are shown.

14h30-14h50: Stefano Vellucci (« Roma Tre » University), Cloaking and magnet-less non-reciprocity through metamaterials

14h50-15h10: Camille Gaulon (University Paris Diderot), Acoustic properties and dissipation in liquid foams

15h10-15h30: Tao Yang (Technical University of Liberec), Relationship between sound absorption property and transmission behavior of Struto nonwoven

15h30-15h50: Coffee Break

15h50-16h10: Jiangyi Zhang (LAUM CNRS UMR 6613), Nonlinear Membrane-Type Acoustic Metamaterials: Harmonic generation and solitons

16h10-16h30: Livija Cveticanin (University of Novi Sad), Negative effective mass in the mass-in-mass subsystem with cubic nonlinearity

16h40-17h10: Round table (discussion on the presented topics and possible future developments within the WG1)

For more details, please see the flyer and the week agenda and how to reach the venue.

Participation and registration

Registration is closed!

Participation in the Workshop is free of charge. 20 support grants will be provided on competitive basis to participants who are presenting their work during the Workshop. Priority will be given to PhD students and Early Career Investigators (i.e. researcher whose career spun less than 8 years since the date of the PhD). More information is provided on the registration form.

Deadlines

Abstract submission is closed participants have been informed about the decision on 19th December 2016.

Organising Committee:

Anton Krynkin (Work Group 1 Leader) – a.krynkin@sheffield.ac.uk
Francesco Asdrubali (Local Organiser) – francesco.asdrubali@uniroma3.it
Pauline Rasera (DENORMS Grant Manager) – denorms@univ-lemans.fr
Jean-Philippe Groby (DENORMS Chair) – jean-philippe.groby@univ-lemans.fr
Olga Umnova (DENORMS Vice-Chair) – o.umnova@salford.ac.uk

Scientific Committee:

Keith Attenborough (Open University, UK)
Anne-Christine Hladky-Hennion, (CNRS, ISEN-IEMN, France)
Jean-Philippe Groby (CNRS, the Maine University, France)
Kirill Horoshenkov (The University of Sheffield, UK)
Andrew Norris (Rutgers University, USA)
Olga Umnova (The University of Salford, UK)
Victor Sanchez-Morcillo (UPV – EPSG, Spain)
Chrysoula Tsogka (Foundation for Research and Technology, Greece)
Livija Cveticanin (University of Novi Sad, Serbia)

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