Publications
294 results found
Brûlé S, Enoch S, Guenneau S, et al., 2018, Seismic Metamaterials: Controlling Surface Rayleigh Waves Using Analogies with Electromagnetic Metamaterials, World Scientific Series in Nanoscience and Nanotechnology, Pages: 301-337
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- Citations: 6
Craster R, Antonakakis T, Guenneau S, 2018, Dynamic Homogenization of Acoustic and Elastic Metamaterials and Phononic Crystals, World Scientific Series in Nanoscience and Nanotechnology, Pages: 1-56
Craster R, Guenneau S, Maier SA, 2018, Preface by Main Editor, World Scientific Series in Nanoscience and Nanotechnology, Vol: 16, Pages: V-VI, ISSN: 2301-301X
Roux P, Rupin M, Lemoult F, et al., 2018, New Trends Toward Locally-Resonant Metamaterials at the Mesoscopic Scale, World Scientific Series in Nanoscience and Nanotechnology, Pages: 251-299
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- Citations: 1
Guenneau S, Brule S, Enoch S, et al., 2018, Some challenges regarding cloaking and earthquake protection, 12th International Congress on Artificial Materials for Novel Wave Phenomena (METAMATERIALS), Publisher: IEEE, Pages: 158-160
Brûlé S, Javelaud EH, Enoch S, et al., 2017, Flat lens effect on seismic waves propagation in the subsoil., Sci Rep, Vol: 7
We show that seismic energy simulated by an artificial source that mainly propagates Rayleigh surface waves, is focused in structured soil made of a grid of holes distributed in the ground. We carry out large-scale field tests with a structured soil made of a grid consisting of cylindrical and vertical holes in the ground and a low frequency artificial source (<10 Hz). This allows the identification of a distribution of energy inside the grid, which can be interpreted as the consequence of a dynamic anisotropy akin to an effective negative refraction index. Such a flat lens reminiscent of what Veselago and Pendry envisioned for light opens avenues in seismic metamaterials to counteract partially or totally the most devastating components of seismic signals.
Brule S, Ungureanu B, Achaoui Y, et al., 2017, Metamaterial-like transformed urbanism, INNOVATIVE INFRASTRUCTURE SOLUTIONS, Vol: 2, ISSN: 2364-4176
Craster R, Guenneau S, Hutridurga H, et al., 2017, Regularized transformation optics for transient heat transfer, 2017 11th International Congress on Engineered Material Platforms for Novel Wave Phenomena (METAMATERIALS), Publisher: IEEE, Pages: 127-129
Dupont G, Remy F, Kimmoun O, et al., 2017, Type of dike using C-shaped vertical cylinders, Physical Review B, Vol: 96, ISSN: 2469-9950
The present study investigates a way to design dikes which can filter the wavelengths of ocean surface waves. This offers the possibility to achieve a structure that can attenuate waves associated with storm swell, without affecting coastline in other conditions. Our approach is based on low-frequency resonances in metamaterials combined with Bragg frequencies for which waves cannot propagate in periodic lattices.
Cherkaev E, Guenneau S, Wellander N, 2017, Homogenization of Maxwell equations with a quasiperiodic non-linear conductivity, Pages: 373-375
We homogenize a time domain formulation of Maxwell's equations with a nonlinear conductivity assumption in a quasiperiodic composite setting.
Aznavourian R, Puvirajesinghe TM, Brule S, et al., 2017, Spanning the scales of mechanical metamaterials using time domain simulations in transformed crystals, graphene flakes and structured soils, JOURNAL OF PHYSICS-CONDENSED MATTER, Vol: 29, ISSN: 0953-8984
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- Citations: 10
Guenneau S, Diatta A, Puvirajesinghe TM, et al., 2017, Cloaking and anamorphism for light and mass diffusion, JOURNAL OF OPTICS, Vol: 19, ISSN: 2040-8978
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- Citations: 6
Colombi A, Craster R, Colquitt D, et al., 2017, Elastic wave control beyond band-gaps: shaping the flow of waves in plates and half-spaces with subwavelength resonant rods., Frontiers in Mechanical Engineering, Vol: 3, ISSN: 2297-3079
In metamaterial science, local resonance and hybridization are key phenomena strongly influencing the dispersion properties; the metasurface discussed in this article created by a cluster of resonators, subwavelength rods, atop an elastic surface being an exemplar with these features. On this metasurface, band-gaps, slow or fast waves, negative refraction, and dynamic anisotropy can all be observed by exploring frequencies and wavenumbers from the Floquet–Bloch problem and by using the Brillouin zone. These extreme characteristics, when appropriately engineered, can be used to design and control the propagation of elastic waves along the metasurface. For the exemplar we consider, two parameters are easily tuned: rod height and cluster periodicity. The height is directly related to the band-gap frequency and, hence, to the slow and fast waves, while the periodicity is related to the appearance of dynamic anisotropy. Playing with these two parameters generates a gallery of metasurface designs to control the propagation of both flexural waves in plates and surface Rayleigh waves for half-spaces. Scalability with respect to the frequency and wavelength of the governing physical laws allows the application of these concepts in very different fields and over a wide range of lengthscales.
Colombi A, Roux P, Miniaci M, et al., 2017, The role of large scale computing behind the development of seismic (and elastic) metamaterials., 2017 11th International Congress on Engineered Material Platforms for Novel Wave Phenomena (METAMATERIALS), Publisher: IEEE, Pages: 406-408
Colombi A, Ageeva V, Smith RJ, et al., 2017, Enhanced sensing and conversion of ultrasonic Rayleigh waves by elastic metasurfaces, Scientific Reports, Vol: 7, ISSN: 2045-2322
Recent years have heralded the introduction of metasurfaces that advantageously combine the vision of sub- wavelength wave manipulation, with the design, fabrication and size advantages associated with surface excitation. An important topic within metasurfaces is the tailored rainbow trapping and selective spatial frequency separation of electromagnetic and acoustic waves using graded metasurfaces. This frequency dependent trapping and spatial frequency segregation has implications for energy concentrators and associated energy harvesting, sensing and wave filtering techniques. Different demonstrations of acoustic and electromagnetic rainbow devices have been performed, however not for deep elastic substrates that support both shear and compressional waves, together with surface Rayleigh waves; these allow not only for Rayleigh wave rainbow effects to exist but also for mode conversion from surface into shear waves. Here we demonstrate experimentally not only elastic Rayleigh wave rainbow trapping, by taking advantage of a stop-band for surface waves, but also selective mode conversion of surface Rayleigh waves to shear waves. These experiments performed at ultrasonic frequencies, in the range of 400-600 kHz, are complemented by time domain numerical simulations. The metasurfaces we design are not limited to guided ultrasonic waves and are a general phenomenon in elastic waves that can be translated across scales.
Lefebvre G, Antonakakis T, Achaoui Y, et al., 2017, Unveiling extreme anisotropy in elastic structured media, Physical Review Letters, Vol: 118, ISSN: 0031-9007
Periodic structures can be engineered to exhibit unique properties observed at symmetry points, such as zero group velocity, Dirac cones, and saddle points; identifying these and the nature of the associated modes from a direct reading of the dispersion surfaces is not straightforward, especially in three dimensions or at high frequencies when several dispersion surfaces fold back in the Brillouin zone. A recently proposed asymptotic high-frequency homogenization theory is applied to a challenging time-domain experiment with elastic waves in a pinned metallic plate. The prediction of a narrow high-frequency spectral region where the effective medium tensor dramatically switches from positive definite to indefinite is confirmed experimentally; a small frequency shift of the pulse carrier results in two distinct types of highly anisotropic modes. The underlying effective equation mirrors this behavior with a change in form from elliptic to hyperbolic exemplifying the high degree of wave control available and the importance of a simple and effective predictive model.
Achaoui Y, Antonakakis T, Brule S, et al., 2017, Clamped seismic metamaterials: Ultra-low broad frequency stop-bands, New Journal of Physics, Vol: 9, ISSN: 1367-2630
The regularity of earthquakes, their destructive power, and the nuisance of ground vibration in urbanenvironments, all motivate designs of defence structures to lessen the impact of seismic and groundvibration waves on buildings. Low frequency waves, in the range 1–10 Hz for earthquakes and up to afew tens of Hz for vibrations generated by human activities, cause a large amount of damage, orinconvenience; depending on the geological conditions they can travel considerable distances andmay match the resonant fundamental frequency of buildings. The ultimate aim of any seismicmetamaterial, or any other seismic shield, is to protect over this entire range of frequencies; the longwavelengths involved, and low frequency, have meant this has been unachievable to date. Notably thisis scalable and the effects also hold for smaller devices in ultrasonics. There are three approaches toobtaining shielding effects: bragg scattering, locally resonant sub-wavelength inclusions and zerofrequencystop-band media. The former two have been explored, but the latter has not and isexamined here. Elastic flexural waves, applicable in the mechanical vibrations of thin elastic plates, canbe designed to have a broad zero-frequency stop-band using a periodic array of very small clampedcircles. Inspired by this experimental and theoretical observation, all be it in a situation far removedfrom seismic waves, we demonstrate that it is possible to achieve elastic surface (Rayleigh)wavereflectors at very large wavelengths in structured soils modelled as a fully elastic layer periodicallyclamped to bedrock. We identify zero frequency stop-bands that only exist in the limit of columns ofconcrete clamped at their base to the bedrock. In a realistic configuration of a sedimentary basin 15 mdeep we observe a zero frequency stop-band covering a broad frequency range of 0–30 Hz.
Farhat M, Chen PY, Guenneau S, et al., 2017, Localized surface plate modes via flexural Mie resonances, Physical Review B, Vol: 95, ISSN: 2469-9950
Surface-plasmon polaritons are naturally generated upon excitation of metals with high-frequency electromagnetic waves. However, the concept of spoof plasmons has made it possible to generate plasmoniclike effects in microwave electrodynamics, magnetics, and even acoustics. Similarly, in this paper, the concept of localized surface plate modes (SPMs) is introduced. It is demonstrated that SPMs can be generated on a two-dimensional (clamped or stress-free) cylindrical surface with subwavelength corrugations, which resides on a thin elastic plate, under excitation by an incident flexural plane wave. Numerical characterization of this corrugated rigid structure shows that it is elastically equivalent to a cylindrical scatterer with dispersive but uniformly negative flexural rigidity. This, indeed, suggests that plasmoniclike elastic materials can be engineered with potential applications in various areas including earthquake sensing and elastic imaging and cloaking.
Colquitt DJ, Colombi A, Craster RV, et al., 2017, Seismic metasurfaces: sub-wavelength resonators and Rayleigh wave interaction, Journal of the Mechanics and Physics of Solids, Vol: 99, Pages: 379-393, ISSN: 0022-5096
We consider the canonical problem of an array of rods, which act as resonators, placed on an elastic substrate; the substrate being either a thin elastic plate or an elastic half-space. In both cases the flexural plate, or Rayleigh surface, waves in the substrate interact with the resonators to create interesting effects such as effective band-gaps for surface waves or filters that transform surface waves into bulk waves; these effects have parallels in the field of optics where such sub-wavelength resonators create metamaterials, and metasurfaces, in the bulk and at the surface respectively. Here we carefully analyse this canonical problem by extracting the dispersion relations analytically thereby examining the influence of both the flexural and compressional resonances on the propagating wave. For an array of resonators atop an elastic half-space we augment the analysis with numerical simulations. Amongst other effects, we demonstrate the striking effect of a dispersion curve that transitions from Rayleigh wave-like to shear wave-like behaviour and the resultant change in displacement from surface to bulk waves.
Brule S, Achaoui Y, Ungureanu B, et al., 2017, New composite geomaterials for the mitigation of seismic effects, Pages: 1485-1488
The high density of deep foundation or ground reinforcement techniques in urban area, leads researchers to believe in a significant interaction of these buried structures with a certain component of the seismic signal. A promising way to cause a modification on the seismic disturbance is to create a complete dynamic artificial anisotropy by implementing geometrical elements, full or empty, in the soil. The physical process is the interference of waves (body or surface waves) scattered from surfaces or objects. The effects of the dynamic anisotropy are reinforced by the local resonance of implemented, which are disposed along a grid according to transformation elastodynamics and morphing tools that could theoretically lead to an ideal cloak detouring waves around a protected area. In this periodic or non-periodic media, the desired effects are total reflection (Bragg's effect), band-gaps, wave-path control, attenuation by energy-dissipation, etc.
Diatta A, Achaoui Y, Brûlé S, et al., 2016, Control of Rayleigh-like waves in thick plate Willis metamaterials, AIP Advances, Vol: 6
Recent advances in control of anthropic seismic sources in structured soil led us to explore interactions of elastic waves propagating in plates (with soil parameters) structured with concrete pillars buried in the soil. Pillars are 2 m in diameter, 30 m in depth and the plate is 50 m in thickness. We study the frequency range 5 to 10 Hz, for which Rayleigh wave wavelengths are smaller than the plate thickness. This frequency range is compatible with frequency ranges of particular interest in earthquake engineering. It is demonstrated in this paper that two seismic cloaks' configurations allow for an unprecedented flow of elastodynamic energy associated with Rayleigh surface waves. The first cloak design is inspired by some approximation of ideal cloaks' parameters within the framework of thin plate theory. The second, more accomplished but more involved, cloak design is deduced from a geometric transform in the full Navier equations that preserves the symmetry of the elasticity tensor but leads to Willis' equations, well approximated by a homogenization procedure, as corroborated by numerical simulations. The two cloaks's designs are strickingly different, and the superior efficiency of the second type of cloak emphasizes the necessity for rigour in transposition of existing cloaks's designs in thin plates to the geophysics setting. Importantly, we focus our attention on geometric transforms applied to thick plates, which is an intermediate case between thin plates and semi-infinite media, not studied previously. Cloaking efficiency (reduction of the disturbance of the wave wavefront and its amplitude behind an obstacle) and protection (reduction of the wave amplitude within the center of the cloak) are studied for ideal and approximated cloaks' parameters. These results represent a preliminary step towards designs of seismic cloaks for surface Rayleigh waves propagating in sedimentary soils structured with concrete pillars.
Guenneau S, Petiteau D, Zerrad M, et al., 2016, Cloaking for heat and mass diffusion, Transformation Wave Physics: Electromagnetics, Elastodynamics, and Thermodynamics, Pages: 313-334, ISBN: 9789814669955
Guenneau S, Dupont G, Enoch S, et al., 2016, Experiments on cloaking for surface water waves, Transformation Wave Physics: Electromagnetics, Elastodynamics, and Thermodynamics, Pages: 287-312, ISBN: 9789814669955
Farhat M, Chen PY, Enoch S, et al., 2016, Preface, ISBN: 9789814669955
Spacetime transformations as a design tool for a new class of composite materials (metamaterials) have proved successful recently. The concept is based on the fact that metamaterials can mimic a transformed but empty space. Light rays follow trajectories according to Fermats principle in this transformed electromagnetic, acoustic, or elastic space instead of laboratory space. This allows one to manipulate wave behaviors with various exotic characteristics such as (but not limited to) invisibility cloaks. This book is a collection of works by leading international experts in the fields of electromagnetics, plasmonics, elastodynamics, and diffusion waves. The experimental and theoretical contributions will revolutionize ways to control the propagation of sound, light, and other waves in macroscopic and microscopic scales. The potential applications range from underwater camouflaging and electromagnetic invisibility to enhanced biosensors and protection from harmful physical waves (e.g., tsunamis and earthquakes). This is the first book that deals with transformation physics for all kinds of waves in one volume, covering the newest results from emerging topical subjects such as transformational plasmonics and thermodynamics.
Liu Y, Gralak B, Guenneau S, 2016, Finite element analysis of electromagnetic waves in two-dimensional transformed bianisotropic media, Optics Express, Vol: 24, Pages: 26479-26493
We analyze the wave propagation in two-dimensional bianisotropic media with the Finite Element Method (FEM). Starting from the Maxwell-Tellegen's equations in bianisotropic media, we derive some system of coupled Partial Differential Equations (PDEs) for longitudinal electric and magnetic field components. These PDEs are implemented in FEM using a solid mechanics formulation. Perfectly Matched Layers (PMLs) are also discussed to model unbounded bianisotropic media. The PDEs and PMLs are then implemented in a finite element software, and transformation optics is further introduced to design some bianisotropic media with interesting functionalities, such as cloaks, concentrators and rotators. In addition, we propose a design of metamaterial with concentric layers made of homogeneous media with isotropic permittivity, permeability and magnetoelectric parameters that mimic the required effective anisotropic tensors of a bianisotropic cloak in the long wavelength limit (homogenization approach). Our numerical results show that transformation based electromagnetic metamaterials can be extended to bianisotropic media.
Diatta A, Guenneau S, 2016, Elastodynamic cloaking and field enhancement for soft spheres, JOURNAL OF PHYSICS D-APPLIED PHYSICS, Vol: 49, ISSN: 0022-3727
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- Citations: 9
Moughames J, Jradi S, Chan TM, et al., 2016, Wavelength-scale light concentrator made by direct 3D laser writing of polymer metamaterials, SCIENTIFIC REPORTS, Vol: 6, ISSN: 2045-2322
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- Citations: 25
Diatta A, Kadic M, Wegener M, et al., 2016, Scattering problems in elastodynamics, PHYSICAL REVIEW B, Vol: 94, ISSN: 2469-9950
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- Citations: 16
Achaoui Y, Ungureanu B, Enoch S, et al., 2016, Seismic waves damping with arrays of inertial resonators, EXTREME MECHANICS LETTERS, Vol: 8, Pages: 30-37, ISSN: 2352-4316
Farhat M, Chen PY, Guenneau S, et al., 2016, Cloaking through cancellation of diffusive wave scattering, PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES, Vol: 472, ISSN: 1364-5021
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- Citations: 11
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