共查询到20条相似文献,搜索用时 15 毫秒
1.
MingHao Zhao Na Li CuiYing Fan GuangTao Xu 《International Journal of Solids and Structures》2008,45(6):1804-1824
Using the fundamental solutions for three-dimensional transversely isotropic magnetoelectroelastic bimaterials, the extended displacements at any point for an internal crack parallel to the interface in a magnetoelectroelastic bimaterial are expressed in terms of the extended displacement discontinuities across the crack surfaces. The hyper-singular boundary integral–differential equations of the extended displacement discontinuities are obtained for planar interface cracks of arbitrary shape under impermeable and permeable boundary conditions in three-dimensional transversely isotropic magnetoelectroelastic bimaterials. An analysis method is proposed based on the analogy between the obtained boundary integral–differential equations and those for interface cracks in purely elastic media. The singular indexes and the singular behaviors of near crack-tip fields are studied. Three new extended stress intensity factors at crack tip related to the extended stresses are defined for interface cracks in three-dimensional transversely isotropic magnetoelectroelastic bimaterials. A penny-shaped interface crack in magnetoelectroelastic bimaterials is studied by using the proposed method.The results show that the extended stresses near the border of an impermeable interface crack possess the well-known oscillating singularity r?1/2±iε or the non-oscillating singularity r?1/2±κ. Three-dimensional transversely isotropic magnetoelectroelastic bimaterials are categorized into two groups, i.e., ε-group with non-zero value of ε and κ-group with non-zero value of κ. The two indexes ε and κ do not coexist for one bimaterial. However, the extended stresses near the border of a permeable interface crack have only oscillating singularity and depend only on the mechanical loadings. 相似文献
2.
Bao-Lin Wang Hua-Yu Zhang Jie-Cai Han 《Archive of Applied Mechanics (Ingenieur Archiv)》2007,77(8):541-558
Magnetoelectroelastic materials are inherently brittle and prone to fracture. Therefore, it is important to evaluate the fracture
behavior of these advanced materials. In this paper, a periodic array of cracks in a transversely isotropic magnetoelectroelastic
material is investigated. Hankel transform is applied to solve elastic displacements, electric potential and magnetic potential.
The problem is reduced into a system of integral equations. Both impermeable and permeable crack-face electromagnetic boundary
conditions assumptions are investigated. Quantities of the stress, electric displacement and magnetic induction and their
intensity factor are obtained. Effect of the crack spacing on these quantities is investigated in details. 相似文献
3.
V. S. Kirilyuk 《International Applied Mechanics》1999,35(9):889-896
The feasibility of controlling the stress intensity factors for plane cracks of arbitrary form (distributed in a plane perpendicular
to isotropy axis in a transversely isotropic material) which are subjected to symmetric mechanical loading by heating the
material is demonstrated by using the congruence theorem and making an analogy between isotropic and transversely isotropic
materials based on the theory of thermoelasticity. It is shown that a thermal load which fully compensates for the mechanical
load can be created within the range in which the material behaves linearly. If it turns out to be technically impossible
to create the necessary thermal load, a simpler temperature regime can be chosen that will “cancel” the mechanical force field
with a certain factor of safety.
S. P. Timoshenko Institute of Mechanics, National Academy of Sciences of Ukraine, Kiev. Translated from Prikladnaya Mekhanika,
Vol. 35, No. 9, pp. 29–37, September, 1999. 相似文献
4.
V. S. Kirilyuk 《International Applied Mechanics》2008,44(10):1106-1118
The static equilibrium of a transversely isotropic magnetoelectroelastic body with a plane crack of arbitrary shape in the
isotropy plane under antisymmetric mechanical loading is studied. The relationships between the stress intensity factors (SIFs)
for an infinite magnetoelectroelastic body and the SIFs for a purely elastic body with the same crack and under the same antisymmetric
loading are established. This enables the SIFs for a magnetoelectroelastic body to be found directly from the analogous problem
of elasticity. As an example of using this result, the SIFs for penny-shaped, elliptic, and parabolic cracks in a magnetoelectroelastic
body under antisymmetric mechanical loading are found
Translated from Prikladnaya Mekhanika, Vol. 44, No. 10, pp. 37–51, October 2008. 相似文献
5.
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
6.
V. I. Fabrikant 《Archive of Applied Mechanics (Ingenieur Archiv)》2001,71(12):807-826
Summary In the first part of the article an infinite circular cylinder is considered, made of transversely isotropic elastic material
and weakened by a plane crack perpendicular to its axis O
z. The crack is opened by an arbitrary normal stress. The second part is devoted to the same crack loaded by an arbitrary tangential
stress. The complete solution in both cases is presented as a sum of the solution of a similar problem of a crack in an infinite
space and an integral transform term, the parameters of which are determined from a set of linear algebraic equations derived
from the boundary conditions. Governing integral equations with respect to the yet unknown crack displacement discontinuities
are obtained. In the case of a circular crack, these equations can be inverted and solved by the method of consecutive interations.
Received 30 November 2000; accepted for publication 3 May 2001 相似文献
7.
《International Journal of Solids and Structures》2003,40(11):2833-2850
First, the general solution for transversely isotropic magnetoelectroelastic media is given concisely in form of five harmonic functions. Second, the extended Boussinesq and Cerruti solutions for the magnetoelectroelastic half-space are obtained in terms of elementary functions by utilizing this general solution. Third, the coupled fields for elliptical Hertzian contact of magnetoelectroelastic bodies are solved in smooth and frictional cases. At last, the graphic results are presented. 相似文献
8.
9.
IntroductionMechanicsandphysicsofmediapossessingsimultaneouslypiezoelectric ,piezomagneticandmagnetoelectriceffects ,namely ,magnetoelectroelasticsolids,haveattractedmoreandmoreattentionduetotheirgreatpotentialapplicationsinthetechnologiesofsmartandadaptivematerialsystem[1] .Sometheoreticalinvestigationsappearedintheliteratureinclude :1)Theexistenceproblemofsurfacewavesinsemi_infiniteanisotropicmagnetoelectroelasticmediawithvariousboundaryconditions[2 ,3 ] ;2 )Green’sfunctions[4~ 7] ;3)Inho… 相似文献
10.
V. M. Levin Th. Michelitsch I. Sevostianov 《Archive of Applied Mechanics (Ingenieur Archiv)》2000,70(10):673-693
Summary Piezoelectric material containing an inhomogeneity with different electroelastic properties is considered. The coupled electroelastic
fields within the inclusion satisfy a system of integral equations solved in a closed form in the case of an ellipsoidal inclusion.
The solution is utilized to find the concentration of the electroelastic fields around an inhomogeneity, and to derive the
expression for the electric enthalpy of the electroelastic medium with an ellipsoidal inclusion that is relevant for various
applications. Explicit closed-form expressions are found for the electroelastic fields within a spheroidal inclusion embedded
in the transversely isotropic matrix. Results are specialized for a cylinder, a flat rigid disk and a crack. For a penny-shaped
crack, the quantities entering the crack propagation criterion are found explicitly.
Received 17 February 2000; accepted for publication 9 May 2000 相似文献
11.
12.
Summary In this paper, the method of numerical integration along bicharacteristics is generalized to the case of layered transversely
isotropic medium for analysing the axisymmetric stress wave propagation. The stability of the present scheme is studied. The
advantages and limitations of the method are discussed.
Received 12 June 1996; accepted for publication 6 May 1997 相似文献
13.
基于双横观各向同性材料基本解的对偶边界元方法,分析了半无限横观各向同性材料中两条共面裂纹的相互作用问题。裂纹面上分别作用着法向和切向两种均布荷载,材料的各向同性面及裂纹面平行于半无限域自由面。数值计算得到了该类裂纹的应力强度因子(SIF)值和两条共面裂纹相互作用的SIF值影响系数。根据数值结果分析了自由面对该类裂纹SIF值的影响,以及裂纹间距与形状、自由面对SIF值影响系数的影响。结果表明,自由面对作用法向力时的该类裂纹SIF值有明显的影响,裂纹间距与形状对SIF值影响系数影响较大,但自由面对SIF值影响系数基本无影响。 相似文献
14.
横观各向同性材料三维裂纹问题的数值分析 总被引:1,自引:0,他引:1
严格从三维横观各向同性材料弹性空间问题的Green函数出发,采用Hadamard有限部积分概念,导出了三维状态下单位位移间断(位错)集度的基本解.在此基础上,将三维任意形状的片状裂纹问题归结为求解-组以未知位移间断表示的超奇异积分方程;并给出了边界元离散形式.对方程中出现的超奇异积分,采用了Had-alnard定义的有限部积分来处理.论文最后给出了若干典型片状裂纹问题的数值算例,数值结果表明了本文方法是非常有效的. 相似文献
15.
Thermal effects are well known to manifest themselves as additional volume integral terms in the direct formulation of the boundary integral equation (BIE) for linear elastic solids when using the boundary element method (BEM). This domain integral has been successfully transformed in an exact manner to surface ones only in isotropy and in 2D anisotropy, thereby restoring the BEM as a truly boundary solution technique. The difficulties with extending it to 3D general anisotropic solids lie in the mathematical complexity of the Green’s function and its derivatives for such materials. These quantities are required items in the BEM formulation. In this paper, the exact, analytical transformation of the volume integral associated with thermal effects to surface ones is achieved for a transversely isotropic material using a similar approach which the authors have previously employed for the same task in BEM for 2D general anisotropy. A numerical scheme, however, needs to be employed to evaluate some of the new terms introduced in the surface integrals that arise from this process here. The mathematical soundness of the formulation is demonstrated by a few examples; the numerical results obtained are checked by alternative means, including those obtained from the commercial FEM code, ANSYS. 相似文献
16.
17.
A three-dimensional analysis is performed for an infinite transversely isotropic elastic body containing an insulated rigid sheet-like inclusion (an anticrack) in the isotropy plane under a remote perpendicularly uniform heat flow. A general solution scheme is presented for the resulting boundary-value problems. Accurate results are obtained by constructing suitable potential solutions and reducing the thermal problem to a mechanical analog for the corresponding isotropic problem. The governing boundary integral equation for a planar anticrack of arbitrary shape is obtained in terms of a normal stress discontinuity. As an illustration, a complete solution for a rigid circular inclusion is obtained in terms of elementary functions and analyzed. This solution is compared with that corresponding to a penny-shaped crack problem. 相似文献
18.
The integral-differential equations for three-dimensional planar interfacial cracks of arbitrary shape in transversely isotropic bimaterials were derived by virtue of the Somigliana identity and the fundamental solutions, in which the displacement discontinuities across the crack faces are the unknowns to be determined. The interface is parallel to both the planes of isotropy. The singular behaviors of displacement and stress near the crack border were analyzed and the stress singularity indexes were obtained by integral equation method. The stress intensity factors were expressed in terms of the displacement discontinuities. In the non-oscillatory case, the hyper-singular boundary integral-differential equations were reduced to hyper-singular boundary integral equations similar to those of homogeneously isotropic materials. 相似文献
19.
Marmo Francesco Sessa Salvatore Vaiana Nicol De Gregorio Daniela Rosati Luciano 《Continuum Mechanics and Thermodynamics》2020,32(3):775-802
Continuum Mechanics and Thermodynamics - We present a systematic approach to the derivation of complete solutions for three-dimensional transversely isotropic elastic problems. The class of... 相似文献
20.
An analog of the δ
c
-model is used to reduce the limit-equilibrium problem for a transversely isotropic spherical shell with surface cracks to
a system of integral equations. An algorithm for numerical solution of this system is proposed 相似文献