Abstract
In this paper, we explore the use of micromorphic-type interface conditions for the modeling of a finite-sized metamaterial. We show how finite-domain boundary value problems can be approached in the framework of enriched continuum mechanics (relaxed micromorphic model) by imposing continuity of macroscopic displacement and of generalized tractions, as well as additional conditions on the micro-distortion tensor and on the double-traction. The case of a metamaterial slab of finite width is presented, its scattering properties are studied via a semi-analytical solution of the relaxed micromorphic model and compared to a direct finite-element simulation encoding all details of the selected microstructure. The reflection and transmission coefficients obtained via the two methods are presented as a function of the frequency and of the direction of propagation of the incident wave. We find excellent agreement for a large range of frequencies going from the long-wave limit to frequencies beyond the first band-gap and for angles of incidence ranging from normal to near-parallel incidence. The present paper sets the basis for a new viewpoint on finite-size metamaterial modeling enabling the exploration of meta-structures at large scales.
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Notes
It is worth noticing that the parameters of the relaxed micromorphic model are “constant” in the sense that they do not depend on frequency, as it is common to see when considering homogenized models for metamaterials. This implies that, once an estimate of the parameters is made for a given metamaterial, it will be possible to study the metamaterial’s response for any type of applied external load. In some sense, one obtains a true “metamaterial’s characterization” via the determination of few constant parameters that are known once for all.
For example, \((A\cdot v)_i=A_{ij}v_j\), \((A\cdot B)_{ik}=A_{ij}B_{jk}\), \(A:B=A_{ij}B_{ji}\), \((C\cdot B)_{ijk}=C_{ijp}B_{pk}\), \((C:B)_{i}=C_{ijp}B_{pj}\), \(\left\langle v,w\right\rangle = v\cdot w = v_i w_i\), \(\left\langle A, B \right\rangle = A_{ij}B_{ij}\), etc.
The operators \(\nabla \), \({{\,\mathrm{curl}\,}}\) and \({{\,\mathrm{Div}\,}}\) are the classical gradient, curl and divergence operators. In symbols, for a field u of any order, \((\nabla u)_i=u_{,i}\), for a vector field v, \(({{\,\mathrm{curl}\,}}v)_i = \epsilon _{ijk}v_{k,j}\) and for a field w of order \(k>1\), \(({{\,\mathrm{Div}\,}}w)_{i_1 i_2\ldots i_{k-1}} = w_{i_1 i_2\ldots i_k,i_k}\)
The use of the letter t is reserved for the time variable and will not be used to denote the components of tensors. Analogously, the subscript t will denote derivation with respect to the scalar variable t. Finally, the subscript tt will indicate the second derivative with respect to time.
We could consider more complex expressions for the curvature term, which would also include anisotropy and in fact, such expressions will be explored in further works. Here, we want to show that curvature terms provide small corrections to the overall behavior of the metamaterial and so, we limit ourselves to a simplified isotropic expression.
For example, the fourth-order tensor \(\mathbb {C}_e\) is written as \(\widetilde{\mathbb {C}}_e\) in Voigt notation.
As we will show in the following, \(k_2\), which is the second component of the wave-number, is always supposed to be known and is given by Snell’s law when imposing interface conditions on a given interface.
Here again, as in the case of a Cauchy medium, \(k_2\) will be fixed and given by Snell’s law when imposing interface conditions.
In a more general perspective, mixed interface conditions in which traction and double-traction are proportional to displacement and micro-distortion, respectively, could also be envisaged (e.g., [18]). Nevertheless, the direct interest of this kind of interface conditions is not evident for the case under study and will not be considered in the present work.
We denote by \(\widetilde{v}\) the first two components of the micromorphic field v defined in Eq. (20).
The index \(j\in \{L,S\}\) for the elastic field \(u^j\) indicates the fact that \(u^j\) is the solution field generated by an L- or S-incident wave, respectively. Nevertheless, \(u^j\) typically contains in itself coupled L and S waves as a result of scattering.
We limit ourselves to the plane-strain case, so that we set \(u^j_3=0\) and \(u^j_{i,3}=0\), \(j\in \{L,s\}\), \(i \in \{1,2,3\}\).
References
Aivaliotis, A., Daouadji, A., Barbagallo, G., Tallarico, D., Neff, P., Madeo, A.: Low-and high-frequency Stoneley waves, reflection and transmission at a Cauchy/relaxed micromorphic interface. arXiv preprint arXiv:1810.12578 (2018)
Aivaliotis, A., Daouadji, A., Barbagallo, G., Tallarico, D., Neff, P., Madeo, A.: Microstructure-related Stoneley waves and their effect on the scattering properties of a 2D Cauchy/relaxed-micromorphic interface. Wave Motion 90, 99–120 (2019)
Aivaliotis, A., Tallarico, D., Daouadji, A., Neff, P., Madeo, A.: Relaxed micromorphic broadband scattering for finite-size meta-structures—a detailed development. arXiv preprint (2019)
Auld, B.A.: Acoustic Fields and Waves in Solids, vol. I. Wiley, New York (1973)
Barbagallo, G., Madeo, A., d’Agostino, M.V., Abreu, R., Ghiba, I.-D., Neff, P.: Transparent anisotropy for the relaxed micromorphic model: macroscopic consistency conditions and long wave length asymptotics. Int. J. Solids Struct. 120, 7–30 (2017). https://doi.org/10.1016/j.ijsolstr.2017.01.030
Barbagallo, G., Tallarico, D., d’Agostino, M.V., Aivaliotis, A., Neff, P., Madeo, A.: Relaxed micromorphic model of transient wave propagation in anisotropic band-gap metastructures. Int. J. Solids Struct. 162, 148–163 (2019)
Basu, U., Chopra, A.K.: Perfectly matched layers for time-harmonic elastodynamics of unbounded domains: theory and finite-element implementation. Comput. Methods Appl. Mech. Eng. 192(11–12), 1337–1375 (2003)
Bloch, F.: Über die Quantenmechanik der Elektronen in Kristallgittern. Zeitschrift für Physik 52(7–8), 555–600 (1929)
Chen, H., Chan, C.T.: Acoustic cloaking and transformation acoustics. J. Phys. D Appl. Phys. 43(11), 113001 (2010)
Craster, R.V., Guenneau, S.: Acoustic Metamaterials: Negative Refraction, Imaging, Lensing and Cloaking, vol. 166. Springer, Berlin (2012)
d’Agostino, M.V., Barbagallo, G., Ghiba, I.-D., Eidel, B., Neff, P., Madeo, A.: Effective description of anisotropic wave dispersion in mechanical band-gap metamaterials via the relaxed micromorphic model. J. Elast. 25, 22 (2019). https://doi.org/10.1007/s10659-019-09753-9. (Accepted)
Eringen, A.C.: Microcontinuum Field Theories. Springer, New York (1999). https://doi.org/10.1007/978-1-4612-0555-5
Floquet, G.: Sur les equations differentielles lineaires. Ann. ENS [2] 12(1883), 47–88 (1883)
Geers, M.G.D., Kouznetsova, V.G., Brekelmans, W.A.M.: Multi-scale computational homogenization: trends and challenges. J. Comput. Appl. Math. 234(7), 2175–2182 (2010)
Kadic, M., Bückmann, T., Schittny, R., Wegener, M.: Metamaterials beyond electromagnetism. Rep. Progr. Phys. 76(12), 126501 (2013)
Krushynska, A.O., Kouznetsova, V.G., Geers, M.G.D.: Towards optimal design of locally resonant acoustic metamaterials. J. Mech. Phys. Solids 71, 179–196 (2014)
Leckner, J.: Theory of Reflection: Reflection and Transmission of Electromagnetic, Particle and Acoustic Waves. Wiley, New York (1973)
Lurie, S., Solyaev, Y., Volkov, A., Volkov-Bogorodskiy, D.: Bending problems in the theory of elastic materials with voids and surface effects. Math. Mech. Solids 23(5), 787–804 (2018)
Madeo, A., Neff, P., Ghiba, I.-D., Placidi, L., Rosi, G.: Band gaps in the relaxed linear micromorphic continuum. Zeitschrift für Angewandte Mathematik und Mechanik 95(9), 880–887 (2014)
Madeo, A., Neff, P., Ghiba, I.-D., Placidi, L., Rosi, G.: Wave propagation in relaxed micromorphic continua: modeling metamaterials with frequency band-gaps. Contin. Mech. Thermodyn. 27(4–5), 551–570 (2015). https://doi.org/10.1007/s00161-013-0329-2
Madeo, A., Barbagallo, G., Agostino, M.V., Placidi, L., Neff, P.: First evidence of non-locality in real band-gap metamaterials: determining parameters in the relaxed micromorphic model. Proc. R. Soc. A Math. Phys. Eng. Sci. 472(2190), 20160169 (2016). https://doi.org/10.1098/rspa.2016.0169
Madeo, A., Neff, P., d’Agostino, M.V., Barbagallo, G.: Complete band gaps including non-local effects occur only in the relaxed micromorphic model. Comptes Rendus Mécanique 344(11–12), 784–796 (2016). https://doi.org/10.1016/j.crme.2016.07.002
Madeo, A., Neff, P., Ghiba, I.-D., Rosi, G.: Reflection and transmission of elastic waves in non-local band-gap metamaterials: a comprehensive study via the relaxed micromorphic model. J. Mech. Phys. Solids 95, 441–479 (2016). https://doi.org/10.1016/j.jmps.2016.05.003
Madeo, A., Barbagallo, G., Collet, M., d’Agostino, M.V., Miniaci, M., Neff, P.: Relaxed micromorphic modeling of the interface between a homogeneous solid and a band-gap metamaterial: new perspectives towards metastructural design. Math. Mech. Solids (2017). https://doi.org/10.1177/1081286517728423
Madeo, A., Collet, M., Miniaci, M., Billon, K., Ouisse, M., Neff, P.: Modeling phononic crystals via the weighted relaxed micromorphic model with free and gradient micro-inertia. J. Elast. 130(1), 59–83 (2017). https://doi.org/10.1007/s10659-017-9633-6
Madeo, A., Neff, P., Aifantis, E.C., Barbagallo, G., d’Agostino, M.V.: On the role of micro-inertia in enriched continuum mechanics. Proc. R. Soc. A Math. Phys. Eng. Sci. 473(2198), 20160722 (2017). https://doi.org/10.1098/rspa.2016.0722
Madeo, A., Neff, P., Barbagallo, G., d’Agostino, M.V., Ghiba, I.-D.: A review on wave propagation modeling in band-gap metamaterials via enriched continuum models. In: dell’Isola, F., Sofonea, M., Steigmann, D.J. (eds.) Mathematical Modelling in Solid Mechanics, Advanced Structured Materials, pp. 89–105. Springer, Berlin (2017). https://doi.org/10.1007/978-981-10-3764-1_6
Mindlin, R.D.: Micro-structure in linear elasticity. Arch. Ration. Mech. Anal. 16(1), 51–78 (1964)
Misseroni, D., Colquitt, D.J., Movchan, A.B., Movchan, N.V., Jones, I.S.: Cymatics for the cloaking of flexural vibrations in a structured plate. Sci. Rep. 6, 23929 (2016)
Neff, P., Ghiba, I.-D., Madeo, A., Placidi, L., Rosi, G.: A unifying perspective: the relaxed linear micromorphic continuum. Contin. Mech. Thermodyn. 26(5), 639–681 (2014). https://doi.org/10.1007/s00161-013-0322-9
Neff, P., Ghiba, I.-D., Lazar, M., Madeo, A.: The relaxed linear micromorphic continuum: well-posedness of the static problem and relations to the gauge theory of dislocations. Q. J. Mech. Appl. Math. 68(1), 53–84 (2015). https://doi.org/10.1093/qjmam/hbu027
Neff, P., Madeo, A., Barbagallo, G., d’Agostino, M.V., Abreu, R., Ghiba, I.-D.: Real wave propagation in the isotropic-relaxed micromorphic model. Proc. R. Soc. A Math. Phys. Eng. Sci. 473(2197), 20160790 (2017). https://doi.org/10.1098/rspa.2016.0790
Neff, P., Eidel, B., d’Agostino, M.V., Madeo, A.: Identification of scale-independent material parameters in the relaxed micromorphic model through model-adapted first order homogenization. J. Elast., 1–30 (2019). https://doi.org/10.1007/s10659-019-09752-w
Norris, A.N.: Acoustic cloacking. Acoust. Today 11(1), 38–46 (2015)
Owczarek, S., Ghiba, I.-D., d’Agostino, M.-V., Neff, P.: Nonstandard micro-inertia terms in the relaxed micromorphic model: well-posedness for dynamics. Math. Mech. Solids 24(10), 3200–3215 (2019)
Platts, S.B., Movchan, N.V., McPhedran, R.C., Movchan, A.B.: Two-dimensional phononic crystals and scattering of elastic waves by an array of voids. Proc. R. Soc. A 458(2026), 2327–2347 (2002)
Rokoš, O., Ameen, M.M., Peerlings, R.H.J., Geers, M.G.D.: Micromorphic computational homogenization for mechanical metamaterials with patterning fluctuation fields. J. Mech. Phys. Solids 123, 119–137 (2019)
Sridhar, A., Kouznetsova, V.G., Geers, M.G.D.: A general multiscale framework for the emergent effective elastodynamics of metamaterials. J. Mech. Phys. Solids 111, 414–433 (2018)
Srivastava, A., Willis, J.R.: Evanescent wave boundary layers in metamaterials and sidestepping them through a variational approach. Proc. R. Soc. A 473(2200), 20160765 (2017)
Willis, J.R.: Dynamics of composites. In: Continuum Micromechanics, pp. 265–290. Springer (1997)
Willis, J.R.: Exact effective relations for dynamics of a laminated body. Mech. Mater. 41(4), 385–393 (2009)
Willis, J.R.: Effective constitutive relations for waves in composites and metamaterials. In Proceedings of the Royal Society of London A: Mathematical, Physical and Engineering Sciences, vol. 467, pp. 1865–1879. The Royal Society (2011)
Willis, J.R.: The construction of effective relations for waves in a composite. Comptes Rendus Mécanique 340(4–5), 181–192 (2012)
Willis, J.R.: Negative refraction in a laminate. J. Mech. Phys. Solids 97, 10–18 (2016)
Acknowledgements
Angela Madeo and Domenico Tallarico acknowledge funding from the French Research Agency ANR, “METASMART” (ANR-17CE08-0006). Angela Madeo acknowledges support from IDEXLYON in the framework of the “Programme Investissement d’Avenir” ANR-16-IDEX-0005. All the authors acknowledge funding from the “Région Auvergne-Rhône-Alpes” for the “SCUSI” project for international mobility France/Germany.
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Aivaliotis, A., Tallarico, D., d’Agostino, MV. et al. Frequency- and angle-dependent scattering of a finite-sized meta-structure via the relaxed micromorphic model. Arch Appl Mech 90, 1073–1096 (2020). https://doi.org/10.1007/s00419-019-01651-9
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DOI: https://doi.org/10.1007/s00419-019-01651-9
Keywords
- Enriched continuum mechanics
- Anisotropic metamaterials
- Band-gaps
- Wave propagation
- Relaxed micromorphic model
- Interface
- Scattering
- Finite-sized meta-structures