Tunable Acoustic Wave Propagation Through Planar Auxetic Metamaterial

2017 ◽  
Vol 34 (2) ◽  
pp. 113-122 ◽  
Author(s):  
J. H. He ◽  
H. H. Huang
Keyword(s):  
Wave Propagation ◽  
Acoustic Waves ◽  
Floquet Theory ◽  
Wave Attenuation ◽  
Transmission Loss ◽  
Sound Waves ◽  
Finite Element Analyses ◽  
Acoustic Wave Propagation ◽  
Experimental Transmission ◽  
Specific Frequency

AbstractThis paper presents a tunable planar auxetic metamaterial (PAM) for controlling and filtering acoustic waves and provides guidelines for bandgap design of the proposed PAMs. Numerical results for deformed and undeformed PAMs were obtained from several finite element analyses based on Bloch–Floquet theory. The acoustic band structures of the PAMs were calculated with periodic boundaries. Tunable bandgaps in certain frequency ranges were generated by various deformations applied to the PAMs. Wave attenuation in experimental transmission loss at specific frequencies was demonstrated, showing favorable agreement with the bandgaps obtained from numerical calculations. Both the numerical and experimental results indicate that the proposed structure demonstrates great tunability and offers significant advantages over the regular materials for controlling sound wave propagation and filtering sound waves within specific frequency ranges.

EXPERIENCE ON ACOUSTIC WAVE PROPAGATION IN ROCK SALT IN THE FREQUENCY RANGE 1-100 kHz AND CONCLUSIONS WITH RESPECT TO THE FEASIBILITY OF A ROCK SALT DOME AS NEUTRINO DETECTOR

2006 ◽  
Vol 21 (supp01) ◽  
pp. 30-34 ◽  
Author(s):  
GERD MANTHEI ◽  
JÜRGEN EISENBLÄTTER ◽  
THOMAS SPIES
Keyword(s):  
Wave Propagation ◽  
Acoustic Wave ◽  
Rock Salt ◽  
Acoustic Waves ◽  
Wave Attenuation ◽  
High Energy ◽  
Neutrino Detector ◽  
Frequency Range ◽  
Acoustic Wave Propagation

Rock salt is a promising material for the detection of acoustic waves generated by interactions of high energy neutrinos. The economical feasibility of an acoustic neutrino detector strongly depends on the spacing between the acoustic sensors. In this paper we report on our experience on acoustic wave propagation and wave attenuation in rock salt in the frequency range of 1 to 100 kHz and some conclusions with respect to the usefulness of rock salt as a neutrino detector. The experience bases on long-term acoustic emission measurements in a salt mine.

scholarly journals The acoustic waves propagation in a cylindrical waveguide with the laminar flow

2018 ◽  
Vol 211 ◽  
pp. 04005
Author(s):  
Alexander Petrov ◽  
Valentina Rumyantseva
Keyword(s):  
Wave Propagation ◽  
Laminar Flow ◽  
Acoustic Waves ◽  
Approximate Analytical Solution ◽  
Acoustic Oscillations ◽  
Acoustic Wave Propagation ◽  
Inhomogeneous Flow ◽  
Waves Propagation ◽  
The Individual ◽  
Hydrodynamics Equations

The problem of modeling of acoustic wave propagation in inhomogeneous flow is considered. There is an approximate analytical solution of the hydrodynamics equations in the presence of annular acoustic oscillations source in the case of laminar flow. Special attention is to paid to the propagation of acoustic waves modes. The amplitudes and phases dependences of the individual modes on the Mach number in the linear approximation were established.

Bandgap of flexural wave in periodic bi-layer beam

2016 ◽  
Vol 24 (14) ◽  
pp. 2970-2985 ◽  
Author(s):  
Zhiwei Guo ◽  
Meiping Sheng
Keyword(s):  
Wave Propagation ◽  
Floquet Theory ◽  
Wave Attenuation ◽  
Vibration Reduction ◽  
Single Layer ◽  
Beam Theory ◽  
Flexural Wave ◽  
Transmission Characteristic ◽  
Beam Structure ◽  
Software Simulation

A periodic bi-layer beam structure is proposed and the bandgap characteristic of flexural wave is studied in this paper. The single cell is made up of two bi-layer beams with four components. For the infinite structure, the flexural wave bandgap frequency algorithm is theoretically derived through Timoshenko beam theory, Hamilton principle, Bloch-Floquet theory and transfer matrix method. An analytical example is presented to illustrate the bandgap characteristic and FEA software simulation is conducted to demonstrate the validation of the algorithm. For the finite structure, the vibration transmission characteristic is studied with FEA software to show the flexural wave attenuation behavior of the periodic bi-layer beam. The results reveal that, the flexural wave is attenuated gradually in the stopband along the direction of wave propagation, while in the passband, it will propagate without attenuation. Comparisons with periodic single layer beam are studied to verify the convenience and flexibility of bi-layer beam. Finally, parametric influences on bandgaps are discussed, which will help the designers to make a better design for vibration reduction.

Experiments on Damping of Acoustic Waves in Water-Filled Pipes

2006 ◽  
Author(s):  
Vijay Chatoorgoon ◽  
Qizhao Li
Keyword(s):  
Experimental Study ◽  
Wave Propagation ◽  
Acoustic Wave ◽  
Turbulent Flow ◽  
Acoustic Waves ◽  
Model Comparison ◽  
System Response ◽  
Acoustic Wave Propagation ◽  
The Third ◽  
Zero Flow

A simple, fundamental experimental study was conducted to better understand acoustic wave propagation is fluid-filled pipes. Three experiments were undertaken: the first with zero flow and a closed outlet end, the second with turbulent flow and an open outlet end and the third with zero flow and an open outlet end. The intent was to obtain data for model comparison and to determine the effect of turbulent flow on the system response. New insights are obtained and reported.

scholarly journals Nonreciprocal surface acoustic wave propagation via magneto-rotation coupling

2020 ◽  
Vol 6 (32) ◽  
pp. eabb1724 ◽  
Author(s):  
Mingran Xu ◽  
Kei Yamamoto ◽  
Jorge Puebla ◽  
Korbinian Baumgaertl ◽  
Bivas Rana ◽  
...  
Keyword(s):  
Acoustic Wave ◽  
Acoustic Waves ◽  
Wave Attenuation ◽  
Surface Acoustic Waves ◽  
Intrinsic Property ◽  
Coupling Mechanism ◽  
Phonon Coupling ◽  
Acoustic Wave Propagation ◽  
Phonon Interaction ◽  
Magnetoelastic Coupling

A fundamental form of magnon-phonon interaction is an intrinsic property of magnetic materials, the “magnetoelastic coupling.” This form of interaction has been the basis for describing magnetostrictive materials and their applications, where strain induces changes of internal magnetic fields. Different from the magnetoelastic coupling, more than 40 years ago, it was proposed that surface acoustic waves may induce surface magnons via rotational motion of the lattice in anisotropic magnets. However, a signature of this magnon-phonon coupling mechanism, termed magneto-rotation coupling, has been elusive. Here, we report the first observation and theoretical framework of the magneto-rotation coupling in a perpendicularly anisotropic film Ta/CoFeB(1.6 nanometers)/MgO, which consequently induces nonreciprocal acoustic wave attenuation with an unprecedented ratio of up to 100% rectification at a theoretically predicted optimized condition. Our work not only experimentally demonstrates a fundamentally new path for investigating magnon-phonon coupling but also justifies the feasibility of the magneto-rotation coupling application.

Design of Acoustic Cloak by Transmission Line Approach

2008 ◽  
Author(s):  
Shu Zhang ◽  
Nicholas Fang
Keyword(s):  
Wave Propagation ◽  
Transmission Line ◽  
Acoustic Waves ◽  
Effective Density ◽  
Transmission Line Model ◽  
Acoustic Wave Propagation ◽  
Exterior Field ◽  
Acoustic Parameters ◽  
Helmholtz Resonators ◽  
Great Potential Application

This paper proposed an approach to construct the acoustic cloak by a network of subwavelength Helmholtz resonators. Based on transmission line model to describe the acoustic wave propagation inside such effective anisotropic medium, we derived the acoustic parameters such as effective density and compressibility. Our simulation demonstrates the propagation of acoustic waves can be bent and excluded from an object inside the cloak with no perturbation of exterior field, which may have great potential application in ultrasound noise control.

The Zakharov–Kuznetsov equation for nonlinear ion-acoustic waves

1992 ◽  
Vol 47 (1) ◽  
pp. 75-83 ◽  
Author(s):  
K. Murawski ◽  
P. M. Edwin
Keyword(s):  
Wave Propagation ◽  
Fourier Transform ◽  
Acoustic Waves ◽  
Kutta Method ◽  
Acoustic Wave Propagation ◽  
Initial Value ◽  
Ion Acoustic Waves ◽  
Ion Acoustic Wave ◽  
Runge Kutta Method ◽  
Ion Acoustic

The Zakharov-Kuznetsov equation is used to describe ion-acoustic wave propagation in a magnetic environment. An initial-value problem is solved for this equation on the basis of a numerical method that uses the fast-Fourier-transform technique for calculating space derivatives and a fourth-order Runge-Kutta method for the time scheme. Numerical simulations show that the disturbed flat (planar) solitary waves can break up into more robust cylindrical ones. Interactions between these two types of wave, and recurrence phenomena, are also studied.

Velocity-Log Interpretation: The Effect of Rock Bulk Compressibility

1961 ◽  
Vol 1 (04) ◽  
pp. 235-248 ◽  
Author(s):  
J. Geertsma
Keyword(s):  
Wave Propagation ◽  
Acoustic Wave ◽  
Wave Velocity ◽  
Acoustic Waves ◽  
Carbonate Rocks ◽  
Empirical Relationship ◽  
Biot Theory ◽  
Porous Rocks ◽  
Acoustic Wave Propagation ◽  
Log Interpretation

Abstract Tbe relationsbip between porosity and the speed of propagation of acoustic waves in fluid-saturated porous rocks as measured by the Sonic log and by ultrasonic techniques is analyzed. Biot's continuum theory is used to explain the difference in acoustic wave propagation between a dry and a liquid-saturated porous material. The porosity is a variable in this theory. However, the acoustic wave propagation in the dry rock depends too on porosity, and this dependence is not predicted by the theory. Frequently in dry sandstones, a nearly linear relationsbip between reciprocal acoustic wave velocity and porosity is observed in the low-porosity range. The physics behind this behavior is outlined. An empirical relationship of the form, 1/V ~ A + B ø, applies accordingly for many porous dry rocks, provided the porosity is the only variable. The presence of a liquid in the pores changes the value of B, and this change is found to be in agreement with the Biot theory. The time-average relation introduced some years ago results in an equation of the same type 1/V = ø/Vf + (1 - ø)/Vr - but is not based on a sound physical picture. Still, this relation sometimes predicts approximately correct A and B values. Carbonate rocks with their complicated pore structures sometimes show a different relationship between wave velocity and porosity, unfavorable for log interpretation. Examples are presented. The simultaneous presence of calcite, dolomite and anhydrite, with their different grain densities and matrix compressibilities, complicates acoustic-log interpretation in carbonate rocks still further. Other complicating effects of acoustic-log interpretation are discussed. They are related to the influence of shale streaks and natural fractures on the average wave velocity observed by the logging tool and to the effect of adsorption phenomena on wave propagation in unstressed rocks particularly in sandstones.

scholarly journals A porosity-based Biot model for acoustic waves in snow

2015 ◽  
Vol 61 (228) ◽  
pp. 789-798 ◽  
Author(s):  
Rolf Sidler
Keyword(s):  
Wave Propagation ◽  
Acoustic Waves ◽  
Wave Attenuation ◽  
Compressional Wave ◽  
Compressional Waves ◽  
Phase Velocities ◽  
Snow Properties ◽  
Property Space ◽  
Common Observation ◽  
Biot’S Model

AbstractPhase velocities and attenuation in snow cannot be explained by the widely used elastic or viscoelastic models for acoustic wave propagation. Instead, Biot’s model of wave propagation in porous materials should be used. However, the application of Biot’s model is complicated by the large property space of the underlying porous material. Here constant properties for ice and air, and empirical relationships are used to estimate unknown porous properties from snow porosity. Using this set of equations, phase velocities and plane wave attenuation of shear- and compressional waves are predicted as functions of porosity or density. For light snow the peculiarity was found that the velocity of the first compressional wave is lower than that of the second compressional wave that is commonly referred to as the ‘slow’ wave. The reversal of the velocities comes with an increase of attenuation for the first compressional wave. This is in line with the common observation that sound is strongly absorbed in light snow. The results have important implications for the use of acoustic waves to evaluate snow properties and to numerically simulate wave propagation in snow.

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