共查询到20条相似文献,搜索用时 359 毫秒
1.
V. S. Kirilyuk 《International Applied Mechanics》2008,44(3):320-330
The paper addresses a thermoelectroelastic problem for a piezoelectric body with an arbitrarily shaped plane crack in a plane
perpendicular to the polarization axis under a symmetric thermal load. A relationship between the intensity factors for stress
(SIF) and electric displacement (EDIF) in an infinite piezoceramic body with a crack under a thermal load and the SIF for
a purely elastic body with a crack of the same shape under a mechanical load is established. This makes it possible to find
the SIF and EDIF for an electroelastic material from the elastic solution without the need to solve specific problems of thermoelasticity.
The SIF and EDIF for a piezoceramic body with an elliptic crack and linear distribution of temperature over the crack surface
are found as an example
__________
Translated from Prikladnaya Mekhanika, Vol. 44, No. 3, pp. 96–108, March 2008. 相似文献
2.
V. S. Kirilyuk 《International Applied Mechanics》2008,44(7):757-768
The paper establishes a relationship between the solutions for cracks located in the isotropy plane of a transversely isotropic
piezoceramic medium and opened (without friction) by rigid inclusions and the solutions for cracks in a purely elastic medium.
This makes it possible to calculate the stress intensity factor (SIF) for cracks in an electroelastic medium from the SIF
for an elastic isotropic material, without the need to solve the electroelastic problem. The use of the approach is exemplified
by a penny-shaped crack opened by either a disk-shaped rigid inclusion of constant thickness or a rigid oblate spheroidal
inclusion in an electroelastic medium
__________
Translated from Prikladnaya Mekhanika, Vol. 44, No. 7, pp. 47–60, July 2008. 相似文献
3.
V. S. Kirilyuk 《International Applied Mechanics》2006,42(2):152-161
The static equilibrium of an electroelastic transversely isotropic space with a plane crack under antisymmetric mechanical
loads is studied. The crack is located in the plane of isotropy. Relationships are established between the stress intensity
factors (SIFs) for an infinite piezoceramic body and the SIFs for a purely elastic body with a crack of the same form under
the same loads. This makes it possible to find the SIFs for an electroelastic body without the need to solve specific electroelasitc
problems. As an example, the SIFs are determined for a piezoelastic body with penny-shaped and elliptic cracks under shear
__________
Translated from Prikladnaya Mekhanika, Vol. 42, No. 2, pp. 32–42, February 2006. 相似文献
4.
5.
The problem of two unequal collinear straight cracks weakening a poled transversely isotropic piezoelectric ceramic is addressed under semi-permeable electric boundary conditions on the crack faces. The plate has been subjected to combined in-plane normal(to the faces of the cracks) mechanical and electric loads. Problem is formulated employing Stroh formalism and solved using complex variable technique. The elastic field, electric field and energy release rate are obtained in closed analytic form. A case study is presented for poled PZT-5H cracked plate to study the effect of prescribed mechanical load, electric load, inter-crack distance and crack lengths on crack arrest parameters stress intensity factor (SIF), electric displacement intensity factor (EDIF) and mechanical and total energy release rates (ERR). Moreover a comparative study is done of impermeable and semi-permeable crack face boundary conditions on SIF, EDIF and ERR, and results obtained is presented graphically. It is observed that the effect of dielectric medium in the crack gap cannot be ignored. 相似文献
6.
H. G. Beom Y. H. Kim C. Cho C. B. Kim 《Archive of Applied Mechanics (Ingenieur Archiv)》2006,76(1-2):19-31
A crack with an electric displacement saturation zone in an electrostrictive material under purely electric loading is analyzed. A strip saturation model is here employed to investigate the effect of the electrical polarization saturation on electric fields and elastic fields. A closed form solution of electric fields and elastic fields for the crack with the strip saturation zone is obtained by using the complex function theory. It is found that the K
I
-dominant region is very small compared to the strip saturation zone. The generalized Dugdale zone model is also employed in order to investigate the effect of the saturation zone shape on the stress intensity factor. Using the body force analogy, the stress intensity factor for the asymptotic problem of a crack with an elliptical saturation zone is evaluated numerically. 相似文献
7.
The interaction of a screw dislocation with an interfacial edge crack in a two-phase piezoelectric medium is investigated.
Closed-form solutions of the elastic and electrical fields induced by the screw dislocation are derived using the conformal
mapping method in conjunction with the image principle. Based on the electroelastic fields derived, the stress and electric
displacement intensity factors, the image force acting on the dislocation are given explicitly. We find that the stress and
electric displacement intensity factors depend on the effective electroelastic material constants. In the case where one of
two phases is purely elastic, the stress intensity factor and image force are plotted to illustrate the influences of electromechanical
coupling effect, the position of the dislocation and the material properties on the interaction mechanism.
The project supported by the Doctoral Foundation of Hebei Province (B2003113) 相似文献
8.
An internal crack located within a functionally graded material (FGM) strip bonded with two dissimilar half-planes and under an anti-plane load is considered. The crack is oriented in an arbitrary direction. The material properties of strip are assumed to vary exponentially in the thickness direction and two half-planes are assumed to be isotropic. Governing differential equations are derived and to reduce the difficulty of the problem dealing with solution of a system of singular integral equations Fourier integral transform is employed. Semi closed form solution for the stress distribution in the medium is obtained and mode III stress intensity factor (SIF), at the crack tip is calculated and its validity was verified. Finally, the effects of nonhomogeneous material parameter and crack orientation on the stress intensity factor are studied. 相似文献
9.
Anisotropic thermopiezoelectric solids with an elliptic inclusion or a hole under uniform heat flow 总被引:1,自引:0,他引:1
The two-dimensional problem of a thermopiezoelectric material containing an elliptic inclusion or a hole subjected to a remote
uniform heat flow is studied. Based on the extended Lekhnitskii formulation for thermopiezoelectricity, conformal mapping
and Laurent series expansion, the explicit and closed-form solutions are obtained both inside and outside the inclusion (or
hole). For a hole problem, the exact electric boundary conditions on the hole surface are used. The results show that the
electroelastic fields inside the inclusion or the electric field inside the hole are linear functions of the coordinates.
When the elliptic hole degenerates into a slit crack, the electroelastic fields and the intensity factors are obtained. The
effect of the heat flow direction and the dielectric constant of air inside the crack on the thermal electroelastic fields
are discussed. Comparison is made with two special cases of which the closed solutions exist and it is shown that our results
are valid. 相似文献
10.
V. S. Kirilyuk 《International Applied Mechanics》2008,44(2):150-157
The elastic stress state in a piezoelectric body with an arbitrarily oriented elliptic crack under mechanical and electric
loads is analyzed. The solution is obtained using triple Fourier transform and the Fourier-transformed Green’s function for
an unbounded piezoelastic body. Solving the problem for the case of a crack lying in the isotropy plane, for which there is
an exact solution, demonstrates that the approach is highly efficient. The distribution of the stress intensity factors along
the front of a crack in a piezoelectric body under uniform mechanical loading is analyzed numerically for different orientations
of the crack
__________
Translated from Prikladnaya Mekhanika, Vol. 44, No. 2, pp. 39–48, February 2008. 相似文献
11.
Interaction between an arbitrarily located and oriented point force and point charge with a circular crack is considered. Obtained are the exact expressions for the stress intensity factors (SIFs) kj (j=1,2,3) and electric displacement intensity factor (EDIF) kD; they are given in terms of elementary functions. The results are also presented in graphical form. 相似文献
12.
Summary In this paper, we study a two-dimensional electroelastic problem of an infinite piezoelectric body with two circular piezoelectric
inhomogeneities, one of which contains a crack. We formulate the stress intensity factor (SIF) analytically and investigate
it numerically. The problem is solved based on Bueckner's principle, and is reduced to a problem of a singular integral equation
of the first kind with respect to the distribution function of screw dislocation. The effect of interaction between the two
inhomogeneities and the crack on the electroelastic field as well as the control of the SIF by electrical loads is investigated.
Received 18 April 2000; accepted for publication 24 October 2000 相似文献
13.
Using the boundary integral equation method, the problem of stationary heat conduction and thermoelasticity for a semi-infinite
body with a crack parallel to its boundary is solved. Temperature or heat flow on the crack is prescribed. The body boundary
is heat-insulated or is at zero temperature. The dependence of the stress intensity factor on the depth of occurrence of a
circular crack at a constant temperature or under a constant heat flow is studied. In contrast to mechanical loading, thermal
loading shows less SIF values than in an infinite body
__________
Translated from Prikladnaya Mekhanika, Vol. 43, No. 4, pp. 46–54, April 2007. 相似文献
14.
Yongping Wan Yanpeng Yue Zheng Zhong 《International Journal of Solids and Structures》2012,49(21):3008-3021
A mode III crack cutting perpendicularly across the interface between two dissimilar semi-infinite magnetoelectroelastic solid is studied under the combined loads of a line force, a line electric charge and a line magnetic charge at an arbitrary location. The impermeable conditions are implied on the crack faces. The technique developed in literature for the elastic bimaterial with a crack cutting interface is exploited to treat the magnetoelectroelastic bimaterial. The Riemann-Hilbert problem can be formulated and solved based on complex variable method. Analytical solutions can be obtained for the entire plane. The intensity factors around crack tips can be defined for the elastic, electric and magnetic fields. It shows that, no matter where the load position is, the electric displacement intensity factors (EDIFs), as well as the magnetic induction intensity factors (MIIFs), are identical in magnitude but opposite in sign for both crack tips, on condition that a line force is solely applied. Alternatively, if only a line electric charge is considered, then the stress intensity factors (SIFs) and the MIIFs exhibit the behavior. Likewise, if only a line magnetic charge is applied, it turns to the SIFs and the EDIFs instead. In addition, the dependence of the intensity factors is graphically shown with respect to the location of a line force. It is found that the SIF for a crack tip tends to be infinite if the applied force is approaching the tip itself, but the EDIF, with the complete opposite trend, tends to be vanishing. Finally, focusing on the more practical case of piezoelectric/piezomagnetic bimaterial, variation of the SIF along with the moduli as well as the piezo constitutive coefficients is explored. These analyses may provide some guidance for material selection by minimizing the SIF. It is also believed that the results obtained in this paper can serve as the Green’s function for the dissimilar magnetoelectroelastic semi-infinite bimaterial with a crack cutting the interface under general magnetoelectromechanical loads. 相似文献
15.
The non-zero traction condition is introduced in piezoelectric crack problems with the unknown Coulombic traction acting on
the crack surfaces. An analytical solution under this condition is obtained by means of the generalized Stroh formalism and
by accounting for the permittivity of medium inside the crack gap. As the crack in such materials can be thought of as a low-capacitance
medium carrying a potential drop, the Coulombic traction always pulls the two opposite surfaces of the crack together. It
is proved that under relatively larger mechanical loading and relatively smaller electrical field, the Coulombic traction
may be negligible and the previous investigations under the traction-free crack condition may be accepted in a tolerant way,
otherwise the Coulombic traction may lead to some erroneous results with over 10% relative errors. It is also shown that,
unlike the traction-free crack condition, the applied electric field does change the Mode I stress intensity factor (SIF)
for a central crack in an infinite plane piezoelectric material, and in this way may significantly influence piezoelectric
fracture. It is also concluded that the variable tendencies of the normalized SIF and the ERR against the applied electric
field depend on the mechanical loading levels. This load-dependence feature may lead to a transformation of the normalized
SIF and the ERR from an even functional dependence to an odd functional dependence on the applied electric field. 相似文献
16.
通过对耦合的波动方程和方程解耦,用自模拟方法研究了压电材料中反平面裂纹的自相似扩展问题。研究表明:对反平面问题,介质内的耦合场与裂纹扩展速度有关,在裂纹尖端有r^-1/2阶的奇异性;动态应力强度因子与电位称载荷有关,与静态结论不同;电位移强度因子与机械载 荷无关,与静态结果的表达形式一致。 相似文献
17.
Penny-shaped and half-plane cracks in a transversely isotropic piezoelectric solid under arbitrary loading 总被引:5,自引:0,他引:5
E. Karapetian I. Sevostianov M. Kachanov 《Archive of Applied Mechanics (Ingenieur Archiv)》2000,70(1-3):201-229
Summary The problem of a penny-shaped crack in a transversely isotropic piezoelectric material loaded by both normal and tangential
tractions and by electric charges is analyzed. Closed-form solutions are obtained for the full electroelastic fields as well
as for the stress and electric displacement intensity factors. Solutions are also obtained for the (non-trivial) limiting
case of a half-plane crack. The results are illustrated on the example of piezoceramics PZT-6B.
Received 12 July 1999; accepted for publication 20 July 1999 相似文献
18.
Summary A finite crack propagating at constant speed in a functionally graded piezoelectric strip (FGPS) bonded to a homogeneous piezoelectric strip is considered. It is assumed that the electroelastic material properties of the FGPS vary exponentially across the thickness of the strip, and that the bimaterial strip is under combined anti-plane mechanical shear and in-plane electrical loads. The analysis is conducted for the electrically unified crack boundary condition, which includes both the traditional permeable and the impermeable ones. By using the Fourier transform, the problem is reduced to the solution of Fredholm integral equations of the second kind. Numerical results for the stress intensity factor and the crack sliding displacement are presented to show the influences of the crack propagation speed, electric loads, FGPS gradation, crack length, electromechanical coupling coefficient, properties of the bonded homogeneous piezoelectric strip and crack location. 相似文献
19.
The exact solution is found to the three-dimensional electroelastic problem for a transversely isotropic piezoceramic body with a spheroidal cavity. The solutions of static electroelastic problems are represented in terms of harmonic functions. The case of stretching the piezoceramic medium at a right angle to the spheroid axis of symmetry is analyzed numerically. The dependence of the stress concentration factor on the geometry of the spheroid and the electromechanical characteristics of the material is studied.Translated from Prikladnaya Mekhanika, Vol. 40, No. 11, pp. 92–105, November 2004.This revised version was published online in April 2005 with a corrected cover date. 相似文献
20.
A closed-form solution is obtained for the problem of a mode-III interfacial edge crack between two bonded semi-infinite dissimilar elastic strips. A general out-of-plane displacement potential for the crack interacting with a screw dislocation or a line force is constructed using conformal mapping technique and existing dislocation solutions. Based on this displacement potential, the stress intensity factor (SIF, KIII) and the energy release rate (ERR, GIII) for the interfacial edge crack are obtained explicitly. It is shown that, in the limiting special cases, the obtained results coincide with the results available in the literature. The present solution can be used as the Green’s function to analyze interfacial edge cracks subjected to arbitrary anti-plane loadings. As an example, a formula is derived correcting the beam theory used in evaluation of SIF (KIII) and ERR (GIII) of bimaterials in the double cantilever beam (DCB) test configuration. 相似文献