We report on a phononic crystal (PC) consisting of square array cylindrical polyvinylchloride inclusions in air that exhibits positive, negative, or zero refraction depending the angle incident sound beam. For all three cases refraction, transmitted beam undergoes splitting upon exiting crystal. These properties are analyzed theoretically using finite difference time domain method and demonstrated experimentally. Band structures equifrequency surfaces (EFSs) calculated with plane-wave...

The negative refraction of transverse elastic waves is demonstrated experimentally in a two-dimensional phononic crystal (PC) made square lattice cylindrical air cavities an aluminum matrix. Dispersion curves this PC exhibit unique branch with phase and group velocities opposite signs broad frequency range. Measurement angles through prismatic included block demonstrates wave.

Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation S. Degraeve, C. Granger, B. Dubus, J. O. Vasseur, M. Pham Thi, A.-C. Hladky-Hennion; Bragg band gaps tunability in an homogeneous piezoelectric rod with periodic electrical boundary conditions. Journal of Applied Physics 21 May 2014; 115 (19): 194508. https://doi.org/10.1063/1.4876757 Download citation file:...

Negative refraction of longitudinal waves is evidenced experimentally in a two-dimensional phononic crystal (PC) with solid matrix. The PC made triangular arrangement steel rods embedded epoxy. dispersion curves present branch negative slope, corresponding to mixed mode predominantly behavior. Experiments are carried out on prism-shaped inserted inside an epoxy block, and excited transducer. Measurement the angle at output side shows through PC. Theoretical results agree quite well...

The properties of a one-dimensional phononic crystal made identical piezoelectric elements separated by thin metallic electrodes connected to the ground are studied theoretically for cases where locations electrical connections change as function time with specific speed. This spatio-temporal modulation boundary conditions results in significant non-linear effects that evidenced numerically. interaction between an incident harmonic longitudinal wave and time-dependent is shown lead frequency...

The realization and the radio-frequency characterization of a tunable strontium titanate (STO) electrostrictive solidly mounted acoustic resonator (SMR) bulk wave are reported. For 430nm thick layer, resonance frequency at 2.2GHz can be switched on with bias voltage 6V tuned ±0.85% between 6 30V. No hysteresis is observed. SMR tunability found to affected by (i) variation coupling factor versus which dominant effect (ii) SrTiO3 stiffness constant electric displacement.

A one-dimensional stack of identical piezoelectric rods is investigated. The device exhibits a band gap related to electrical boundary condition. separate control the central frequency and width performed by an condition involving two different variable capacitances. Because capacitances are grounded, specific model has been developed validated. Finally, experiments unambiguously confirmed previous theoretical observations.

A nonreciprocal system composed of a one-dimensional piezoelectric phononic crystal whose periodic electrical conditions are modulated in time is presented. One-way longitudinal wave propagation studied experimentally and compared to finite element temporal simulations. The modulation performed by prescribing grounded or floating potential on set electrodes through external circuits. This approach makes it possible consider wide range speeds, the large number unit cells allows us...

Two ways of controlling the acoustic waves propagation by external inductance or capacitance in a one-dimensional (1-D) piezomagnetic phononic crystal are investigated. The structure is made identical bars, constituted material, surrounded coil and connected to an impedance. A model longitudinal elastic through periodic developed dispersion equation obtained. Reflection transmission coefficients derived from 2 × transfer matrix formalism that also allows for calculation effective parameters...

Sound absorption by different green wall systems at2 normal incidence is investigated between 100 and 1000 3 Hz.Measurements are conducted in an impedance 4 tube order to estimate the effective acoustic prop-5 erties of plants soils.Using these properties, 6 transfer matrix method employed simulate ab-7 sorption coefficient surface multi-8 layer geometries.Results show that 9 adequate choice geometries may result 10 efficient sound a broad frequency range 11 due two main mechanisms:...

A numerical analysis of negative refraction process is reported using a phononic crystal with an elastic solid matrix. The considered in this study made periodic arrangement holes aluminum. Dispersion curves are discussed and conditions for which can appear identified. These obtained the transverse waves, whereas longitudinal waves evanescent. calculation performed prism shaped crystal, it clearly exhibits angle. Several analyses provided view to characterize wave going out crystal. Finally,...

When a Lamb wave propagates on plate engraved by periodic grating, it may exhibit attenuation. This attenuation is related to coupling of this incident mode with other propagating modes. As the propagation takes place in medium, dispersion curves modes are interest because they passbands and stopbands geometry waveguide. The goal work quantitatively establish relation between value waves width forbidden bands appearing inside Brillouin zone. study performed using finite element method (ATILA code).

Bulk Acoustic Wave (BAW) resonators exhibit attractive properties in terms of power handling capacity and on- chip integration to realize filters the GHz range. A current problem design BAW is existence spurious resonances due Lamb waves propagation. This work demonstrates that wave can be used with high quality factor Ultra-High Frequency/Very High Frequency (UHF/VHF) ranges. Design lateral are performed using finite element modelling. Influence electrode geometry type excitation (one- or...

Propagation of longitudinal acoustic waves in a one-dimensional piezoelectric structure with space-time modulated electrical boundary conditions is investigated. An analytical model allowing the calculation eigenmodes for spatially continuous shifts compared finite difference time domain simulation results discrete set time-varying fixed conditions. Both models predict that such behaves as nonreciprocal device exhibiting unidirectional propagation properties some frequency ranges. The...

Phononic crystals made of piezoelectric composites with 1–3 connectivity are studied theoretically and experimentally. It is shown that they present Bragg band gaps depend on the periodic electrical boundary conditions. These structures have improved properties compared to phononic composed bulk elements, especially existence larger fact do not require severe constraints their aspect ratios. Experimental results an overall agreement theoretical predictions clearly show pass bands stop device...

Theoretical and experimental analyses of piezoelectric stacks submitted to periodical electrical boundary conditions via electrodes are conducted. The presented structures exhibit Bragg band gaps that can be switched on or off by setting in short open circuit. gap frequency width is determined the electromechanical coupling coefficient. This property used design a Fabry-Perot cavity delimited periodic stack. An analytical model based transfer matrix formalism wave propagation inside...