Piezoelectric Slab Research Articles

715 貫通き裂を有する圧電セラミックス積層厚板の電気弾性解析

In this study the plane strain crack problem for a layered piezoelectric plate with a finite crack is considered. The laminated slab is made of a piezoelectric slab bonded between two elastic layers of different physical properties. The Fourier transform techniques are used to reduce the problem to that of solving a singular integral equation. The singular integral equation is solved by using the Gauss-Jacobi integration formula. Numerical calculations are carried out, and the main results presented are the variation of the energy density factors as functions of the geometic parameters, the material properties and the electrical boundary conditions of the layered composites.

Electroelastic Analysis of a Piezoelectric Laminated Slab with a Finite Crack

In this study the plane strain crack problem for a layered piezoelectric plate with a finite crack is considered. The laminated slab is made of a piezoelectric slab bonded between two elastic layers of different physical properties. The Fourier transform techniques are used to reduce the problem to that of solving a singular integral equation. The singular integral equation is solved by using the Gauss-Jacobi integration formula. Numerical calculations are carried out, and the main results presented are the variation of the energy density factors as functions of the geometic parameters, the material properties and the electrical boundary conditions of the layered composites.

Stress concentration in an inhomogeneous piezoelectric slab with crack under constant longitudinal shear

We investigate the singular stress and electric fields in an orthotropic, nonhomogeneous piezoelectric ceramic strip containing a Griffith crack under longitudinal shear. The crack is situated symmetrically and oriented in a direction parallel to the edges of the strip a non-homogeneity is taken along a direction normal to the edges and is assumed to follow an exponential law. This allows to model a variety of media with material constants that vary monotonically along a certain direction. The mathematical problem is reduced to the solution a pair of dual integral equations which are transformed, in turn, into an infinite system of linear algebraic equations solved by Gauss's elimination method. Numerical values for the stress intensity factor a energy release rate are obtained and the results are graphically represented to display the influence of the considered nonhomogeneity.

340 貫通き裂を有する圧電セラミックス厚板の電気弾性解析

340 貫通き裂を有する圧電セラミックス厚板の電気弾性解析

Transient elastic waves propagating in a multi–layered medium subjected to in–plane dynamic loadings. I. Theory

The propagation of elastic transient waves in a multi–layered medium subjected to in–plane loadings is investigated in this study. One of the objectives of this study is to develop an effective analytical method for determining transient full–field solutions in the layered medium. A matrix method is developed by expanding the matrix solution obtained directly from the boundary–value problem in the integral transform domain into a power series of the phase–related reflection and transmission matrix which characterizes the multiple reflections and transmissions of all waves in every layer. The transient response of the multi–layered medium is decomposed into infinite wave groups in which the waves are either reflected by, or transmitted through, the interfaces. The connection between the proposed matrix method and the generalized ray method is established for the layered medium in the transform domain. The matrix representation of the solution enables us to calculate the transient response of the layered medium without tracing the ray path manually. The obtained analytical solution can easily be applied to numerical calculations. The double inverse transform is performed based on Cagniard9s method and the theoretical transient solution for a layered half–space subjected to an in–plane dynamic force will be presented in part II. An experimental set–up that simulates the plane stress condition for a layered half–space was established to obtain the dynamic displacement response. The experimental result agrees well with the theoretical solution. The proposed methodology in this study can be extended to solve more complicated problems such as waves propagating in three–dimensional space.

Wave propagation in a piezoelectric layer

The dispersion relations of oscillation modes in a piezoelectric slab with hexagonal symmetry are given, considering the slab infinite with respect to the axes x1 and x2 with the six-order symmetry axis perpendicular to the x1–x2 plane. Four types of modes are identified: two of them are transversal horizontal and the other two are associated to electrostatic potential waves which determine the longitudinal and flexural modes. The secular equations for these modes are given and numerical results for the piezoelectric transducer ceramic slab are obtained and compared to experimental results with a very good agreement.

Active vibration isolation and excitation by piezoelectric slab with constant feedback gains

A theoretical and experimental study of an active vibration isolation technique for high-precision position control involving use of a piezoelectric slab via the converse piezoelectric effect is presented. A theory of the piezoelectric isolation/excitation is first derived. A physical model made of polyvinylidene fluoride (PVDF) polymer slab is prepared to study its vibration excitation and to evaluate its active vibration isolation by injecting a processed feedback voltage at constant gains. The model is subjected to various amplitudes of base excitation at different frequencies, and the isolation characteristics of the piezoelectric slab are observed. Analytical solutions are in satisfactory agreement with the experimental results. The study shows that the vibration isolation is constant for different voltages at any given frequency, and a linear variation with frequency at constant feedback gains. The piezoelectric excitation is a linear function of excitation voltage for constant frequency and a quadratic function of frequency for constant excitation voltage.

Raman scattering by polaritons in Ti:LiNbO3 waveguides

AbstractA general theory of Raman scattering in piezoelectric slab waveguides is presented. If the anisotropy of the uniaxial waveguide material is sufficiently large, incident slab‐guided waves can be scattered by polaritons of the upper branch of the polariton dispersion curve. The angular dependence ω2(θ) of the scattered‐wave frequency has been calculated in detail, for both y‐ and z‐cut Ti:LiNbO3 waveguides in the polariton frequency range ωp=900–5160 cm−1 (pump wavelength 4880 Å). The detection of weak proton vibrations within the strong polariton Raman spectrum of proton‐exchanged Ti:LiNbO3 waveguides is discussed.

Ultrasonic transducer array shading

First Page

General two-dimensional stressed state of thin piezoelectric slabs

General two-dimensional stressed state of thin piezoelectric slabs

A note on disturbances in a piezoelectric slab

In the present note, the equations of electricity and the equations of motion have been used to investigate the disturbances in a piezoelectric slab excited by a step electric field. The application of the Laplace transform facilitates the solution of the problem.

Elastic wave excitation in piezoelectric slabs: Bardati, F., Baryilai, G., Gérosa, G. Institute of Electrical and Electronics Engineers Transactions on Sonics and Ultrasonics, Vol SU-15, No 4 (October 1968) pp 193–202

Elastic wave excitation in piezoelectric slabs: Bardati, F., Baryilai, G., Gérosa, G. Institute of Electrical and Electronics Engineers Transactions on Sonics and Ultrasonics, Vol SU-15, No 4 (October 1968) pp 193–202

Self-scanned optical sensor using elastic surface waves

A self-scanning optical sensor array that is based on the use of elastic surface waves is described. In the device, a photoconducting material is adjacent to an array of surface wave transducers on a piezoelectric slab. Initial tests have successfully demonstrated the principle of operation.

Elastic wave excitation in piezoelectric slabs

A plane uniform electromagnetic wave traveling in a vacuum region and obliquely impinging on a piezoelectric slab bounded on the opposite side by an infinite isotropic elastic medium has been considered. The power carried by the elastic wave transmitted in this latter elastic medium has been compuftoerd various values of the geometrical parameters and the maxima determined.