Dynamic Anti-Plane Behaviors on Two Dissimilar Piezoelectric Media with an Interfacial Non-Circular Cavity

2012 ◽  
Vol 525-526 ◽  
pp. 293-296
Author(s):  
Tian Shu Song ◽  
Dong Li ◽  
Ming Ju Zhang ◽  
Yue Fa Zhou
Keyword(s):  
Characteristic Parameter ◽  
Mapping Method ◽  
Wave Number ◽  
Circular Cavity ◽  
Piezoelectric Media ◽  
Conformal Mapping Method ◽  
Time Harmonic ◽  
Expansion Technique ◽  
Stress Concentration Factors ◽  
Piezoelectric Characteristic

Dynamic anti-plane behaviors are studied on two dissimilar piezoelectric media with an interfacial non-circular cavity subjected to time harmonic incident anti-plane shearing. Based on Greens function and conformal mapping method, the dynamic stress concentration factors at the edge of the non-circular cavity are obtained by applying the orthogonal function expansion technique. Numerical cases about two dissimilar piezoelectric media with an elliptic cavity are provided with different elliptic axial length ratio, different wave number and different piezoelectric characteristic parameter. The calculating results show that dynamic analyses are of importance at lower frequencies and larger piezoelectric characteristic parameters.

Dynamic Stress Concentration on a Semi-Infinite Piezoelectric Medium With a Circular Cavity Near the Surface

2007 ◽  
Author(s):  
Tianshu Song ◽  
Shilong Wang
Keyword(s):  
Stress Concentration ◽  
Dynamic Stress ◽  
Piezoelectric Medium ◽  
Dynamic Stress Concentration ◽  
Circular Cavity ◽  
Characteristic Parameters ◽  
Time Harmonic ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
Piezoelectric Characteristic

Dynamic interaction is investigated theoretically between a circular cavity and the surface in a semi-infinite piezoelectric medium subjected to time-harmonic incident anti-plane shearing in the present paper. The formulations are based on the method of complex variable and wave function expandedness. Dynamic stress concentration factors at the edge of the circular cavity are obtained by solving boundary value problems with the method of orthogonal function expansion. The calculating results are plotted so as to show how the frequencies of incident wave, the piezoelectric characteristic parameters of the material and the structural geometries influence upon the dynamic stress concentration factors.

Dynamic Antiplane Interaction of Subsurface Circular Cavities in a Semi-Infinite Piezoelectric Medium

2009 ◽  
Author(s):  
Tianshu Song ◽  
Tamman Merhej ◽  
Qingna Shang ◽  
Dong Li
Keyword(s):  
Stress Concentration ◽  
Dynamic Stress ◽  
Numerical Solutions ◽  
Piezoelectric Medium ◽  
Dynamic Stress Concentration ◽  
Characteristic Parameters ◽  
Time Harmonic ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
Piezoelectric Characteristic

In the present work, dynamic interaction is investigated theoretically between several circular cavities near the surface in a semi-infinite piezoelectric medium subjected to time-harmonic incident anti-plane shearing. The analyses are based upon the use of complex variable and multi coordinates. Dynamic stress concentration factors at the edges of the subsurface circular cavities are obtained by solving boundary value problems with the method of orthogonal function expansion. Some numerical solutions about two interacting subsurface circular cavities in a semi-infinite piezoelectric medium are plotted so as to show how the frequencies of incident wave, the piezoelectric characteristic parameters of the material and the structural geometries influence on the dynamic stress concentration factors.

Dynamic Anti-Plane Behaviors of Interacting Circular Cavities in an Infinite Piezoelectric Medium

2008 ◽  
Author(s):  
Tianshu Song ◽  
Dong Li ◽  
Lili Sun
Keyword(s):  
Stress Concentration ◽  
Dynamic Stress ◽  
Piezoelectric Medium ◽  
Dynamic Stress Concentration ◽  
Wave Load ◽  
Plane Shear ◽  
Time Harmonic ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
Piezoelectric Characteristic

In this article, dynamic interaction is investigated theoretically between several circular cavities in an infinite piezoelectric medium under time-harmonic incident anti-plane shear wave load. The theoretical formulations are based upon the use of complex variable and multi-coordinates. Dynamic stress concentration factors at the edges of the circular cavities are obtained by solving boundary value problems with the method of orthogonal function expansion. As examples, some calculating results of two interacting circular cavities in an infinite piezoelectric medium are plotted to show how the frequencies of incident wave, the piezoelectric characteristic parameters of the material and the structural geometries influence on the dynamic stress concentration factors.

Excitation of Guided Waves in Generally Anisotropic Layers Using Finite Sources

1994 ◽  
Vol 61 (2) ◽  
pp. 330-338 ◽  
Author(s):  
J. J. Ditri ◽  
J. L. Rose
Keyword(s):  
Phase Velocity ◽  
Nondestructive Evaluation ◽  
Guided Waves ◽  
Guided Wave ◽  
Wave Number ◽  
Excitation Spectra ◽  
Mode Expansion ◽  
Time Harmonic ◽  
Expansion Technique ◽  
Anisotropic Layers

The excitation of guided wave modes in generally anisotropic layers by finite sized strip sources placed on the surfaces of the layer is examined. The general problem of arbitrarily applied harmonic surface tractions is first solved using the normal mode expansion technique in conjunction with the complex reciprocity relation of elastodynamics. This general solution is then specialized to loading situations modelling those commonly used to excite guided waves in layers for use in nondestructive evaluation. The amplitudes of the generated modes are written as the product of an “excitation function” which depends only on the distribution of the applied tractions and an “excitability function” which depends only on the properties of the specific mode(s) being excited and which determines how receptive the modes are to the applied tractions. Expressions are obtained for the −9 dB wave number and phase velocity bandwidths (σβ and σν respectively) which determine the widths of the wavenumber or phase velocity excitation spectra at the −9 dB generation point. Finally, the problem of transient loading is addressed by superimposing time harmonic solutions via an integration over the dispersion curves of the layer.

Dynamic Anti-Plane Characteristic of an Infinite Piezoelectric Medium With a Non-Circular Cavity

2005 ◽  
Author(s):  
Tianshu Song ◽  
Lili Sun ◽  
Diankui Liu
Keyword(s):  
Electric Field ◽  
Dynamic Stress ◽  
Mapping Method ◽  
Piezoelectric Medium ◽  
Circular Cavity ◽  
Characteristic Parameters ◽  
Stress Concentrations ◽  
Plane Shear ◽  
Concentration Factors ◽  
Piezoelectric Characteristic

In this paper, dynamic stress concentrations are studied in an infinite piezoelectric medium with a non-circular cavity under time harmonic incident anti-plane shear wave and inplane electric field. Based on complex variable and conformal mapping method, the dynamic stress concentration factors and the electric field concentration factors at the boundary of the non-circular cavity are obtained by applying the orthogonal function expansion technique. Numerical examples about an infinite piezoelectric medium with an elliptic cavity are provided with different elliptic axial length ratios, different wave numbers and different piezoelectric characteristic parameters. The calculating results show that dynamic analyses are very important to an infinite piezoelectric medium with a non-circular cavity at lower frequencies and larger piezoelectric characteristic parameters.

Dynamic Anti-Plane Behaviors of a Semi-Infinite Piezoelectric Medium with a Circular Cavity and a Crack near the Surface

2008 ◽  
Vol 385-387 ◽  
pp. 389-392
Author(s):  
Tian Shu Song ◽  
Dong Li ◽  
Xin Wang Wang ◽  
Sheng Li Dong
Keyword(s):  
Stress Intensity ◽  
Stress Concentration ◽  
Dynamic Stress ◽  
Dynamic Stress Intensity Factor ◽  
Piezoelectric Medium ◽  
Dynamic Stress Concentration ◽  
Circular Cavity ◽  
Dynamic Stress Intensity Factors ◽  
Time Harmonic ◽  
Stress Concentration Factors

Dynamic interaction is investigated theoretically between a circular cavity and a crack near the surface in a semi-infinite piezoelectric medium subjected to time-harmonic incident anti-plane shearing in this paper. The formulations are based on the method of complex variable and Green’s function. Dynamic stress concentration factors at the edge of the circular cavity and dynamic stress intensity factors at the crack tip are obtained by solving boundary value problems with the method of orthogonal function expansion. The calculating results are plotted to show how the frequencies and the orientation of incident wave, piezoelectric characteristic parameters of the material and the structural geometries influence upon the dynamic stress concentration factor (DSCF) and dynamic stress intensity factor (DSIF).

The Model for Calculation the Hall Effect Parameter

2004 ◽  
Vol 9 (2) ◽  
pp. 129-138
Author(s):  
J. Kleiza ◽  
V. Kleiza
Keyword(s):  
Magnetic Field ◽  
Field Effect ◽  
Magnetic Field Effect ◽  
Mapping Method ◽  
Sample Thickness ◽  
System Of Nonlinear Equations ◽  
Specific Resistivity ◽  
Conformal Mapping Method ◽  
Effect Parameter ◽  
The Magnetic Field

A method for calculating the values of specific resistivity ρ as well as the product µHB of the Hall mobility and magnetic induction on a conductive sample of an arbitrary geometric configuration with two arbitrary fitted current electrodes of nonzero length and has been proposed an grounded. During the experiment, under the constant value U of voltage and in the absence of the magnetic field effect (B = 0) on the sample, the current intensities I(0), IE(0) are measured as well as the mentioned parameters under the effect of magnetic fields B1, B2 (B1 ≠ B2), i.e.: IE(β(i)), I(β(i)), i = 1, 2. It has been proved that under the constant difference of potentials U and sample thickness d, the parameters I(0), IE(0) and IE(β(i)), I(β(i)), i = 1, 2 uniquely determines the values of the product µHB and specific resistivity ρ of the sample. Basing on the conformal mapping method and Hall’s tensor properties, a relation (a system of nonlinear equations) between the above mentioned quantities has been found.

A conformal-mapping method for predicting the thermal properties of U-shaped borehole heat-exchangers

Geothermics ◽  
2014 ◽  
Vol 50 ◽  
pp. 66-75 ◽  
Author(s):  
Nai-Wen Liang ◽  
Ching-Hsien Lai ◽  
Chien-Yeh Hsu ◽  
Yuan-Ching Chiang ◽  
Chih-Chung Chang ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Conformal Mapping ◽  
Heat Exchangers ◽  
Mapping Method ◽  
Conformal Mapping Method ◽  
Borehole Heat Exchangers
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