Wave Propagation in a Piezoelectric Coupled Solid Medium

2002 ◽  
Vol 69 (6) ◽  
pp. 819-824 ◽  
Author(s):  
Q. Wang

Shear horizontal (SH) wave propagation in a semi-infinite solid medium surface bonded by a layer of piezoelectric material abutting the vacuum is investigated in this paper. The dispersive characteristics and the mode shapes of the deflection, the electric potential, and the electric displacements in the thickness direction of the piezoelectric layer are obtained theoretically. Numerical simulations show that the asymptotic phase velocities for different modes are the Bleustein surface wave velocity or the shear horizontal wave velocity of the pure piezoelectric medium. Besides, the mode shapes of the deflection, electric potential, and electric displacement show different distributions for different modes and different wave number. These results can be served as a benchmark for further analyses and are significant in the modeling of wave propagation in the piezoelectric coupled structures.

2010 ◽  
Vol 10 (02) ◽  
pp. 299-313 ◽  
Author(s):  
Q. WANG ◽  
N. WU ◽  
S. T. QUEK

An accurate modeling of the piezoelectric effect of coupled structures is essential to application of piezoelectric materials as sensors and actuators in engineering structures, such as Micro-Electro-Mechanical Systems and Interdigital Transducer for health monitoring of structures. This paper presents a simulation for the shear horizontal wave propagation in an infinite metal plate surface bonded by a piezoelectric layer with open electrical circuit, with focus on the dispersion characteristics of a metal core bonded by a layer of piezoelectric material to be used in health monitoring of structures. The dispersive characteristics and mode shapes of the deflection, electric potential, and electric displacement of the piezoelectric layer are theoretically derived. The results from numerical simulations show that the phase velocity of the piezoelectric coupled plate approaches the bulk-shear wave velocity of the substrate at high wavenumbers. The mode shapes of electric potential and deflection of the piezoelectric layer with steel substrates change from a shape with few zero nodes to one with more zero nodes at higher wavenumbers and with thicker piezoelectric layer. For the coupled plate with gold substrates at higher wavenumbers, the electric potential is found to jump from null at the interface of the piezoelectric layer and the substrate to a constant at the surface of the piezoelectric layer along the thickness direction. These findings are useful to the design of sensors using the piezoelectric coupled structures.


2004 ◽  
Vol 72 (3) ◽  
pp. 341-350 ◽  
Author(s):  
Q. Wang ◽  
S. T. Quek ◽  
V. K. Varadan

An analytical solution for the shear horizontal wave propagation excited by interdigital transducer in a piezoelectric coupled semi-infinite medium is developed. This solution is an extension of earlier work on wave propagation in a piezoelectric coupled plate with finitely long interdigital transducer by fully taking account of piezoelectric effects in analysis. In the current analysis, the mathematical model for a semi-infinite metal substrate bonded by a layer of interdigital transducer with infinite length is first derived. The theoretical solutions are obtained in terms of elliptic integration of the first kind and of the standard integral representation for Legendre polynomial. The essential hypothesis for the derivation of the analysis is investigated. Based on the solution for infinitely long interdigital transducer, an analytical solution for the wave propagation in this semi-infinite piezoelectric medium excited by a finitely long interdigital transducer is obtained through Fourier transform. This theoretical research can be applied to health monitoring of structures by interdigital transducer. It could also be used as a framework for the design of interdigital transducer in wave excitation of smart structures.


2018 ◽  
Vol 18 (04) ◽  
pp. 1850060 ◽  
Author(s):  
Li-Hong Ma ◽  
Liao-Liang Ke ◽  
Yi-Ze Wang ◽  
Yue-Sheng Wang

Based on the nonlocal theory, this paper develops the Kirchhoff nanoplate and Mindlin nanoplate models for the wave propagation analysis of piezoelectric nanoplates. The effects of small scale parameter and thermo-electro-mechanical loads are incorporated in the nanoplate models. The Hamilton’s principle is employed to derive the governing equations of the nanoplate, which are solved analytically to obtain the dispersion relation for piezoelectric nanoplates. The results show that the nonlocal parameter, temperature change, mechanical load and external electric potential have significant influence on the wave propagation characteristics of the piezoelectric nanoplates. The cut-off wave number is observed to exist for piezoelectric nanoplates subjected to positive electric potential, axial tensile force and temperature rise.


Author(s):  
Amir-Reza Asghari Ardalani ◽  
Ahad Amiri ◽  
Roohollah Talebitooti ◽  
Mir Saeed Safizadeh

Wave dispersion response of a fluid-carrying piezoelectric nanotube is studied in this paper utilizing an improved model for piezoelectric materials which capture a new effect known as flexoelectricity in conjunction with the surface elasticity. For this aim, a higher order shear deformation theory is employed to model the problem. Furthermore, strain gradient effect as well as nonlocal effect is taken into consideration throughout using the nonlocal strain gradient theory (NSGT). Surface elasticity is also considered to make an accurate size-dependent formulation. Additionally, a non-compressible and non-viscous fluid is taken into consideration to model the flow effect. The wave propagation solution is then implemented to the governing equations obtained by Hamiltonian’s approach. The phase velocity and group velocity of the nanotube is determined for three wave modes (i.e. shear, longitudinal and bending waves) to study the influence of various involved factors including strain gradient, nonlocality, flexoelectricity and surface elasticity and flow velocity on the wave dispersion curves. Results reveal a considerable effect of the flexoelectric phenomenon on the wave propagation properties especially at a specific domain of the wave number. The size-dependency of this effect is disclosed. Overall, it is found that the flexoelectricity exhibits a substantial influence on wave dispersion properties of the smart fluid-conveying systems. Hence, such size-dependent effect should be considered to achieve exact and accurate knowledge on wave propagation characteristics of the system.


Ultrasonics ◽  
2014 ◽  
Vol 54 (4) ◽  
pp. 997-1004 ◽  
Author(s):  
P.A. Petcher ◽  
S.E. Burrows ◽  
S. Dixon

2006 ◽  
Vol 128 (4) ◽  
pp. 477-488 ◽  
Author(s):  
A. Chakraborty ◽  
S. Gopalakrishnan

A new spectral plate element (SPE) is developed to analyze wave propagation in anisotropic laminated composite media. The element is based on the first-order laminated plate theory, which takes shear deformation into consideration. The element is formulated using the recently developed methodology of spectral finite element formulation based on the solution of a polynomial eigenvalue problem. By virtue of its frequency-wave number domain formulation, single element is sufficient to model large structures, where conventional finite element method will incur heavy cost of computation. The variation of the wave numbers with frequency is shown, which illustrates the inhomogeneous nature of the wave. The element is used to demonstrate the nature of the wave propagating in laminated composite due to mechanical impact and the effect of shear deformation on the mechanical response is demonstrated. The element is also upgraded to an active spectral plate clement for modeling open and closed loop vibration control of plate structures. Further, delamination is introduced in the SPE and scattered wave is captured for both broadband and modulated pulse loading.


Author(s):  
S. Y. Chen ◽  
M. S. Ju ◽  
Y. G. Tsuei

Abstract A frequency-domain technique to extract the normal mode from the measurement data for highly coupled structures is developed. The relation between the complex frequency response functions and the normal frequency response functions is derived. An algorithm is developed to calculate the normal modes from the complex frequency response functions. In this algorithm, only the magnitude and phase data at the undamped natural frequencies are utilized to extract the normal mode shapes. In addition, the developed technique is independent of the damping types. It is only dependent on the model of analysis. Two experimental examples are employed to illustrate the applicability of the technique. The effects due to different measurement locations are addressed. The results indicate that this technique can successfully extract the normal modes from the noisy frequency response functions of a highly coupled incomplete system.


1962 ◽  
Vol 52 (4) ◽  
pp. 807-822 ◽  
Author(s):  
John T. Kuo ◽  
John E. Nafe

abstract The problem of the Rayleigh wave propagation in a solid layer overlying a solid half space separated by a sinusoidal interface is investigated. The amplitude of the interface is assumed to be small in comparison to the average thickness of the layer or the wave length of the interface. Either by applying Rayleigh's approximate method or by perturbating the boundary conditions at the sinusoidal interface, plane wave solutions for the equations which satisfy the given boundary conditions are found to form a system of linear equations. These equations may be expressed in a determinant form. The period (or characteristic) equations for the first and second approximation of the wave number k are obtained. The phase and group velocities of Rayleigh waves in the present case depend upon both frequency and distance. At a given point on the surface, there is a local phase and local group velocity of Rayleigh waves that is independent of the direction of wave propagation.


1993 ◽  
Vol 115 (3) ◽  
pp. 302-312 ◽  
Author(s):  
J. H. Terhune ◽  
K. Karim-Panahi

The free vibration of cylindrical shells filled with a compressible viscous fluid has been studied by numerous workers using the linearized Navier-Stokes equations, the fluid continuity equation, and Flu¨gge ’s equations of motion for thin shells. It happens that solutions can be obtained for which the interface conditions at the shell surface are satisfied. Formally, a characteristic equation for the system eigenvalues can be written down, and solutions are usually obtained numerically providing some insight into the physical mechanisms. In this paper, we modify the usual approach to this problem, use a more rigorous mathematical solution and limit the discussion to a single thin shell of infinite length and finite radius, totally filled with a viscous, compressible fluid. It is shown that separable solutions are obtained only in a particular gage, defined by the divergence of the fluid velocity vector potential, and the solutions are unique to that gage. The complex frequency dependence for the transverse component of the fluid velocity field is shown to be a result of surface interaction between the compressional and vortex motions in the fluid and that this motion is confined to the boundary layer near the surface. Numerical results are obtained for the first few wave modes of a large shell, which illustrate the general approach to the solution. The axial wave number is complex for wave propagation, the imaginary part being the spatial attenuation coefficient. The frequency is also complex, the imaginary part of which is the temporal damping coefficient. The wave phase velocity is related to the real part of the axial wave number and turns out to be independent of frequency, with numerical value lying between the sonic velocities in the fluid and the shell. The frequency dependencies of these parameters and fluid velocity field mode shapes are computed for a typical case and displayed in non-dimensional graphs.


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