Macrocrack-Microcrack Interaction in Piezoelectric Materials, Part I: Basic Formulations and J-Analysis

1999 ◽  
Vol 66 (2) ◽  
pp. 514-521 ◽  
Author(s):  
Y.-H. Chen ◽  
J.-J. Han
Keyword(s):  
Piezoelectric Materials ◽  
Process Zone ◽  
Electric Displacement ◽  
Transversely Isotropic ◽  
Numerical Results ◽  
Fredholm Integral Equations ◽  
Electric Displacement Intensity Factor ◽  
Poling Direction ◽  
Microcrack Interaction ◽  
Interaction Problem

The macrocrack-microcrack interaction problem in transversely isotropic piezoelectric materials is studied. The microcracks near a macrocrack tip in the process zone are assumed to be parallel to the latter, while the poling direction of the piezoelectric materials is assumed to be perpendicular to the cracks. Three kinds of elementary solutions with different crack configurations and under different loading conditions are given, from which the interaction problem is reduced to a system of Fredholm integral equations by using the pseudo-traction electric displacement method (abbreviated PTED). After the equations are solved numerically, the traditional mode I and mode II stress intensity factors and the electric displacement intensity factor are evaluated. In order to confirm the proposed method as well as the numerical results, a consistency check is proposed which is based on the J-integral analysis and provides a powerful tool to examine the numerical results. Thus, any mistakes are avoided since they would certainly lead to unsatisfied numerical results contrary to the check. It is concluded also that the disturbance of the near-tip electric field provides another source of shielding.

Macrocrack-Microcrack Interaction in Piezoelectric Materials, Part II: Numerical Results and Discussions

1999 ◽  
Vol 66 (2) ◽  
pp. 522-527 ◽  
Author(s):  
Y.-H. Chen ◽  
J.-J. Han
Keyword(s):  
Electric Field ◽  
Mechanical Strain ◽  
Electric Displacement ◽  
Strain Energy Release ◽  
Numerical Results ◽  
Electric Loading ◽  
Electric Displacement Intensity Factor ◽  
Variable Nature ◽  
Crack Problems ◽  
Microcrack Interaction

Numerical results are shown in figures and tables. The major features for the traditional stress intensity factors and the electric displacement intensity factor against the microcrack location angle and the distance of the microcrack center from the macrocrack tip are discussed. It is shown that, unlike single-crack problems, the mechanical loading and the electric loading are coupled together since the microcrack not only releases the near-tip stresses, but also disturbs the near-tip electric field. Furthermore, the influence of the electric loading on the mechanical strain energy release rate (MSERR) at the macrocrack tip is discussed in detail. It is found that the variable nature of the MSERR against the normalized electric loading is monotonic and proportional wherever the parallel microcrack is located near the macrocrack tip. However, the slope of the MSERR's curve considering microcracking diverges far from those without considering microcracking. This finding reveals that, besides the two sources of microcrack shielding discussed by Hutchinson (1987) for brittle solids, the disturbance of the near-tip electric field due to microcracking really provides another source of shielding for piezoelectric solids.

Determination of Mechanics Properties of a Piezoelectric Material Using Indentation Method with a Cylindrical Indenter

2011 ◽  
Vol 335-336 ◽  
pp. 1014-1020 ◽  
Author(s):  
Bin Zhao
Keyword(s):  
Piezoelectric Materials ◽  
Contact Stiffness ◽  
Transversely Isotropic ◽  
Indentation Load ◽  
The Finite Element Method ◽  
Poling Direction ◽  
Piezoelectric Effects ◽  
Piezoelectric Strain ◽  
Piezoelectric Solids

The Finite Element Method (FEM) was used for axisymmetric indentation to investigate mechanics properties of piezoelectric solids (PZT-5H). Since piezoelectric materials are usually treated as transversely isotropic elastic materials, a simple linear relationship between indentation load P and indentation displacement h was presented under a cylindrical indenter. Three different cases (uncouple mechanical case, poled substrate-insulating indenter and poled substrate-conducting indenter) were taken into consideration to study indentation responses. The results showed that polarization could more easily damage the poled substrate than the uncoupled case. At the same displacement the highest indentation load existed in the poled/insulating case and the lowest one was in the uncoupled case because of the polarization influence. Electric potential distributions were given to study the direct piezoelectric effects and the electromechanical phenomena. In addition elastic modulus, contact stiffness, and piezoelectric strain constant were calculated directly through the use of the FEM. The determination of the poling direction is another use for the indentation technique, and the discussion of indentation size effect shows that a bigger indenter is followed by a larger indentation load.

Scattering of anti-plane shear waves by an interface crack between two bonded dissimilar functionally graded piezoelectric materials

2009 ◽  
Vol 465 (2104) ◽  
pp. 1249-1269 ◽  
Author(s):  
B.M Singh ◽  
J Rokne ◽  
R.S Dhaliwal ◽  
J Vrbik
Keyword(s):  
Integral Equations ◽  
Integral Transform ◽  
Piezoelectric Materials ◽  
Mass Density ◽  
Electric Displacement ◽  
Functionally Graded ◽  
Fredholm Integral Equations ◽  
Dual Integral Equations ◽  
Functionally Graded Piezoelectric Materials ◽  
Functionally Graded Piezoelectric

In the present paper, the dynamic behaviour of a Griffith crack situated at the interface of two bonded dissimilar functionally graded piezoelectric materials (FGPMs) is considered. It is assumed that the elastic stiffness, piezoelectric constant, dielectric permittivity and mass density of the FGPMs vary continuously as an exponential function of the x and y coordinates, and that the FGPMs are under anti-plane mechanical loading and in-plane electrical loading. By using an integral transform technique the problem is reduced to four pairs of dual integral equations, which are transformed into four simultaneous Fredholm integral equations with four unknown functions. By solving the four simultaneous Fredholm integral equations numerically the effects of the material properties on the stress and electric displacement intensity factors are calculated and displayed graphically.

scholarly journals Electromechanical response of multilayered piezoelectric BaTiO3/PZT-7A composites with wavy architecture

2021 ◽  
pp. 1045389X2098388
Author(s):  
Wenqiong Tu ◽  
Qiang Chen
Keyword(s):  
Finite Element ◽  
Finite Volume ◽  
Volume Fraction ◽  
Piezoelectric Materials ◽  
Electric Displacement ◽  
Element Model ◽  
Numerical Convergence ◽  
Analysis And Design ◽  
Poling Direction ◽  
Microstructural Effects

Electromechanical laminated composites with piezoelectric phases are increasingly being explored as multifunctional materials providing energy conversion between electric and mechanical energies. The current work explores thus-far undocumented combined microstructural effects of amplitude-to-wavelength ratio, volume fraction, poling direction of piezoelectric phases on both the homogenized properties and localized stress/electric field distributions in multilayered configurations under fully coupled electro-mechanical loading. In particular, the Multiphysics Finite-Volume Direct Averaging Micromechanics (FVDAM) and its counterpart, an in-house micromechanical multiphysics finite-element model, are utilized to investigate the homogenized and localized responses of wavy multilayered piezoelectric BaTiO3/PZT-7A architectures. These two methods generate highly agreeable results. Moreover, we critically examine the convergence of the finite-volume and finite element-based approaches via the Average Stress Theorem and Average Electric Displacement Theorem. The comparison shows the finite volume-based approach possesses a better numerical convergence. This study illustrates the FVDAM’s ability toward the analysis and design of engineered multilayered piezoelectric materials with wavy architecture.

Interaction between a Rigid Cylinder with a Piezoelectric Half-Space with Partial Adhesion

2008 ◽  
Vol 33-37 ◽  
pp. 333-338 ◽  
Author(s):  
Zuo Rong Chen ◽  
Shou Wen Yu
Keyword(s):  
Integral Equations ◽  
Half Space ◽  
Integral Transform ◽  
Mixed Boundary ◽  
Piezoelectric Materials ◽  
Contact Region ◽  
Electric Displacement ◽  
Transversely Isotropic ◽  
Dual Integral Equations ◽  
Slip Region

An axisymmetric problem of interaction of a rigid rotating flat ended punch with a transversely isotropic linear piezoelectric half-space is considered. The contact zone consists of an inner circular adhesion region surrounded by an outer annular slip region with Coulomb friction. Beyond the contact region, the surface of the piezoelectric half-space is free from load. With the aid of the Hankel integral transform, this mixed boundary value problem is formulated as a system of dual integral equations. By solving the dual integral equations, analytical expressions for the tangential stress and displacement, and normal electric displacement on the surface of the piezoelectric half-space are obtained. An explicit relationship between the radius of the adhesion region, the angle of the rotation of the punch, material parameters, and the applied loads is presented. The obtained results are useful for characterization of piezoelectric materials by micro-indentation and micro-friction techniques.

The Crack Tip Fields for Anti-Plane Interfacial Crack between Functionally Graded and Homogeneous Piezoelectric Materials

2014 ◽  
Vol 989-994 ◽  
pp. 719-722
Author(s):  
Yao Dai ◽  
Xiao Chong
Keyword(s):  
Intensity Factor ◽  
Piezoelectric Materials ◽  
Electric Displacement ◽  
Interfacial Crack ◽  
Crack Tip ◽  
Expansion Method ◽  
Functionally Graded ◽  
Displacement Fields ◽  
Functionally Graded Piezoelectric Materials ◽  
Electric Displacement Intensity Factor

The problem of an anti-plane crack situated in the interface of functionally graded piezoelectric materials (FGPMs) and homogeneous piezoelectric materials (HPMs) is considered under the impermeable assumption of crack surfaces. The mechanical and electrical properties of the FGPMs are assumed to be exponential functions of y perpendicular to the crack. The higher order crack tip stress and electric displacement fields for FGPMs and HPMs are obtained by the eigen-expansion method. The stress intensity factor and electric displacement intensity factor are obtained explicitly.

The Higher Order Crack Tip Fields for Interfacial Crack between Linear Functionally Graded and Homogeneous Piezoelectric Materials

2014 ◽  
Vol 1015 ◽  
pp. 97-100
Author(s):  
Yao Dai ◽  
Xiao Chong ◽  
Ying Chen
Keyword(s):  
Piezoelectric Materials ◽  
Electric Displacement ◽  
Interfacial Crack ◽  
Crack Tip ◽  
Higher Order ◽  
Functionally Graded ◽  
Linear Functions ◽  
Intensity Factors ◽  
Crack Tip Fields ◽  
Functionally Graded Piezoelectric Materials

The higher order crack-tip fields for an anti-plane crack situated in the interface between functionally graded piezoelectric materials (FGPMs) and homogeneous piezoelectric materials (HPMs) are presented. The mechanical and electrical properties of the FGPMs are assumed to be linear functions of y perpendicular to the crack. The crack surfaces are supposed to be insulated electrically. By using the method of eigen-expansion, the higher order stress and electric displacement crack tip fields for FGPMs and HPMs are obtained. The analytic expressions of the stress intensity factors and the electric displacement intensity factors are derived.

On the Torsion of Elastic Half Spaces With Embedded Penny-Shaped Flaws

1972 ◽  
Vol 39 (3) ◽  
pp. 786-790 ◽  
Author(s):  
R. D. Low
Keyword(s):  
Integral Equations ◽  
Half Space ◽  
Rigid Inclusion ◽  
Elastic Half Space ◽  
Numerical Results ◽  
Fredholm Integral Equations ◽  
Graphical Displays ◽  
Penny Shaped Crack ◽  
Shaped Crack

The investigation is concerned with some of the effects of embedded flaws in an elastic half space subjected to torsional deformations. Specifically two types of flaws are considered: (a) a penny-shaped rigid inclusion, and (b) a penny-shaped crack. In each case the problem is reduced to a system of Fredholm integral equations. Graphical displays of the numerical results are included.

An Analytical Solution for Transversely Isotropic Simply Supported Thick Rectangular Plates Using Displacement Potential Functions

2011 ◽  
Vol 46 (2) ◽  
pp. 121-142 ◽  
Author(s):  
M Nematzadeh ◽  
M Eskandari-Ghadi ◽  
B Navayi Neya
Keyword(s):  
Isotropic Material ◽  
Transversely Isotropic ◽  
Numerical Results ◽  
Potential Functions ◽  
Constant Thickness ◽  
Rectangular Plates ◽  
Displacement Potential ◽  
Simply Supported ◽  
Axial Forces ◽  
Internal Forces

Using a complete set of displacement potential functions, the exact solution of three-dimensional elasticity equations of a simply supported rectangular plates with constant thickness consisting of a transversely isotropic linearly elastic material subjected to an arbitrary static load is presented. The governing partial differential equations for the potential functions are solved through the use of the Fourier method, which results in exponential and trigonometric expression along the plate thickness and the other two lengths respectively. The displacements, stresses, and internal forces are determined through the potential functions at any point of the body. To prove the validity of this approach, the analytical solutions developed in this paper are degenerated for the simpler case of plates containing isotropic material and compared with the existing solution. In addition, the numerical results obtained from this study are compared with those reported in other researches for the isotropic material, where excellent agreement is achieved for both thin and thick plates. The results show that increasing the thickness ratios of the plate causes compressive axial forces and central shear forces inside the plate. Finally, the internal forces and displacement components are calculated numerically for several kinds of transversely isotropic materials with different anisotropies and are compared with a finite element (FE) solution obtained from the ANSYS software, where the high accuracy of the present method is demonstrated. The effects of the material anisotropy are clearly revealed in the numerical results presented.

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