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IntroductionConcerningtheelasticplaneprobleminaunitcircle ,ZhengShenzhouandZhengXueliangdevelopedaboundaryintegralformulaofthestressfunction[1]:Φ(r,θ) =-( 1 -r2 ) 24π ∫2π0ν( φ)1 -2rcos(θ-φ) r2 dφ 12π∫2π011 -2rcos(θ-ω) r2 dω∫2π0μ( φ)1 -cos(ω-φ) dφ 1 -r22π∫2π0μ( φ)1 -2rcos(θ -φ) r2 dφ ( 0 ≤r <1 ) ,( 1 )whereμ(θ) =Φ(r,θ) |r=1,ν(θ) = Φ n r=1= Φ r r=1.Intheformula ( 1 )theseconditemisastrongsingularintegral,itshouldbeunderstoodasanintegra… 相似文献
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Summary An elementary solution for the multiple circular arc problem is obtained in this paper. The elementary solution is defined
as a particular case of the single circular arc crack problem, in which remote stresses are equal to zero, and two pairs of
concentrated forces are applied at a prescribed point of crack face. By using the principle of superposition, Fredholm integral
equation for the multiple circular arc problem in plane elasticity is obtained. The suggested approach is illustrated by several
numerical examples. If a smaller arc crack is surrounded by a larger arc crack, the stress intensity factors for the former
become rather small. The phenomenon of shielding is illustrated by examples.
Accepted for publication 17 September 1996 相似文献
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The paper deals with a direct central impact of two infinite cylindrical bodies having differently shaped cross sections and
made of different materials. A nonstationary plane problem of elasticity is solved. The contact boundary is moving and determined
during the solution. A mixed boundary-value problem is formulated. Its solution has the form of Fourier series. Satisfying
mixed boundary conditions gives an infinite system of Volterra equations of the second kind for the unknown coefficients of
the series. The basic characteristics of the impact process and their dependence on the physical and mechanical properties
of the bodies are determined numerically
Translated from Prikladnaya Mekhanika, Vol. 45, No. 2, pp. 36–45, February 2009. 相似文献
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From the point of view of energy analysis,the cause that the uniqueness of theboundary integral equation induced from the exterior Helmholtz problem does not hold isinvestigated in this paper.It is proved that the Sommerfeld’s condition at the infinity ischanged so that it is suitable not only for the radiative wave but also for the absorptive wavewhen we use the boundary integral equation to describe the exterior Helmholtz problem.Therefore,the total energy of the system is conservative.The mathematical dealings toguarantee the uniqueness are discussed based upon this explanation 相似文献
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将弹性力学平面问题归化成无奇异边界积分方程,避免了传统的边界元法中的柯西主值(CPV)积分和Hadamard-Finite-Parts(HFP)积分的计算,建立完整的数值求解体系。 相似文献
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黄民丰 《应用数学和力学(英文版)》1997,18(2):157-162
I.IntroductionInelasticmechanics,thereisakindofproblemsthatcouldbesolveddirectlybyequilibriumequations,i.e.,whenal1oftheboundaryconditionsaretheknownstressesorforcessuchasthestressfunction.Becausestressfunctionsmustsatisfyharmonicequationorbi-harmonicequa… 相似文献
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In this paper, we propose a new boundary integral equation for plane harmonic functions. As a new approach, the equation is
derived from the conservation integrals. Every variable in the integral equation has direct engineering interest. When this
integral equation is applied to the Dirichlet problem, one will get an integral equation of the second kind, so that the algebraic
equation system in the boundary element method has diagonal dominance. Finally, this equation is applied to elastic torsion
problems of cylinders of different sections, and satisfactary numerical results are obtained. 相似文献
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Leonid K. Antanovskii 《Meccanica》1991,26(2-3):59-65
In this paper planar viscous flows with a free boundary are further studied using the quasisteady approximation [1]. The introduction of the bianalytical stress-stream function provides an opportunity to adopt the theory of analytical functions. The mode of construction of the Fredholm boundary integral equations is here proposed through the explicit solutions of two Hilbert problems for holomorphic functions with the application of the conformal mappings. The stabiligy of the equilibrium of the annulus liquid layer is investigated by way of example.
Sommario Si prosegue lo studio di flussi piani viscosi con frontiera libera applicando l'approssimazione quasistazionaria [1]. L'introduzione della funzione stress-stream bianalitica consente l'uso della teoria delle funzioni olomorfe. La costruzione delle equazioni integrali di Fredholm al contorno proposta qui si basa sulla risoluzione esplicita di due problemi di Hilbert per funzioni analitiche mediante applicazione della tecnica delle trasformazioni conformi. Come esempio si studia la stabilità dell'equilibrio di uno strato liquido anulare.相似文献
11.
汤任基 《应用数学和力学(英文版)》1991,12(2):193-199
In this paper the crack problem.for two bonded inhomogeneous half-planes isconsidered.It is assumed that the different materials have the same Poisson ratio v.butgenerally speaking,both Young s moduli vary exponentially with the coordinate x indifferent form.Using the single crack solution of the inhomogeneous plane problem andFourier transform technique.the problem is reduced to a Cauchy-type singular integralequation.Several numerical examples to calculate the stress intensity factors are carriedout. 相似文献
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Hu Haichang 《Acta Mechanica Sinica》1992,8(2):127-135
A boundary integral representation of plane biharmonic function is established rigorously by the method of unanalytical continuation
in the present paper. In this representation there are two boundary functions and four constants which bear a one to one correspondence
to biharmonic functions. Therefore the set of boundary integral equations with indirect unknowns based on this representation
is equivalent to the original differential equation formulation. 相似文献
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By means of Fourier integral transformation of generalized fimction, the fimdamental solution for the bending problem of plales on two-parameter foundation is derived in this paper, and the fundamental solution is expanded into a uniformly convergent series.On the basis of the above work, two boundary integral eguations which are suitable to arhitrary shapes and arbitrary boundary conditions are established by means of the Rayleigh-Green identity. The content of the paper provides the powerful theories for the application of BEM in this problem. 相似文献
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Two fundamental solutions for bending problem of Reissner's plates on two-parameter foundation are derived by means of Fourier
integral transformation of generalized function in this paper. On the basis of virtual work principles, three boundar integral
equations which fit for arbitrary shapes, lods and boundary conditions of thick plates are presented according to Hu Haichang's
theory about Reissner's plates. It provides the fundamental theories for the application of BEM. A numerical example is given
for clamped, simply supported and free boundary conditions. The results obtained are satisfactory as compared with the analytical
methods.
Project supported by the P.H.D. Foundation of National Education Committee of China 相似文献
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将不规则区域嵌入到规则的矩形区域,在矩形区域上将弹性平面问题的控制方程采用重心Lagrange插值离散,得到控制方程矩阵形式的离散表达式。在边界节点上利用重心插值离散边界条件,规则区域采用置换法施加边界条件,不规则区域采用附加法施加边界条件,得到求解平面弹性问题的过约束线性代数方程组,采用最小二乘法进行求解,得到整个规则区域上的位移数值解。利用重心插值计算得到不规则区域内任意节点的位移值,计算精度可到10-14以上。数值算例验证了所建立方法的有效性和计算精度。 相似文献
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IntroductionIthasbeenratheralonghistorythattheBoundaryElementMethod (BEM )isappliedtosolvetheplaneelasticityproblems[1~2 ].However,theEBIE ,whichisequivalenttotheoriginalboundaryvalueproblem ,hasnotbeenfullyappreciatedandsolvedinBEMcommunity .TheconventionalboundaryintegralequationswithindirectvariablesarediscussedthoroughlyanditisshownthatthepreviousresultsarenotEBIE ,i.e .,sometimes,thereexistsnosolutionormorethanonesolutiontothem .Themainkeyliesintheexactformoftheexteriorproblems.I… 相似文献
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黄民海 《应用数学和力学(英文版)》1999,20(7):812-818
IntroductionUptonow,therehavebenmanyresearchesontheplaneweldingproblemofisotropicmaterials.e.g.[1]and[2]etc.However,forthepla... 相似文献
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IntroductionTheboundaryelementmethod(BEM)providesanattractivealternativefortheanalysisofengineeringproblems.Itsmainadvantagesareeconomicalandparticularlyconvenientforunboundeddomainandstressconcentrationproblems.Theboundaryintegralequation(BIE)isthe… 相似文献