Elastodynamic solution for plane-strain response of functionally graded thick hollow cylinders by analytical method

An elastodynamic solution for plane-strain response of functionally graded thick hollow cylinders subjected to uniformly-distributed dynamic pressures at boundary surfaces is presented. The material properties, except Poisson’s ratio, are assumed to vary through the thickness according to a power law function. To achieve an exact solution, the dynamic radial displacement is divided into two quasi-static and dynamic parts, and for each part, an analytical solution is derived. The quasi-static solution is obtained by means of Euler’s equation, and the dynamic solution is derived using the method of the separation of variables and the orthogonal expansion technique. The radial displacement and stress distributions are plotted for various functionally graded material (FGM) hollow cylinders under different dynamic loads, and the advantages of the presented method are discussed. The proposed analytical solution is suitable for analyzing various arrangements of hollow FGM cylinders with arbitrary thickness and arbitrary initial conditions, which are subjected to arbitrary forms of dynamic pressures distributed uniformly on their boundary surfaces.     

Elastodynamic solution for plane-strain response of functionally graded thick hollow cylinders by analytical method

An elastodynamic solution for plane-strain response of functionally graded thick hollow cylinders subjected to uniformly-distributed dynamic pressures at boundary surfaces is presented. The material properties, except Poisson’s ratio, are assumed to vary through the thickness according to a power law function. To achieve an exact solution, the dynamic radial displacement is divided into two quasi-static and dynamic parts, and for each part, an analytical solution is derived. The quasi-static solution is obtained by means of Euler’s equation, and the dynamic solution is derived using the method of the separation of variables and the orthogonal expansion technique. The radial displacement and stress distributions are plotted for various functionally graded material (FGM) hollow cylinders under different dynamic loads, and the advantages of the presented method are discussed. The proposed analytical solution is suitable for analyzing various arrangements of hollow FGM cylinders with arbitrary thickness and arbitrary initial conditions, which are subjected to arbitrary forms of dynamic pressures distributed uniformly on their boundary surfaces.     

Transient thermal stresses in an orthotropic hollow cylinder for axisymmetric problems

For the thermoelastic dynamic axisymmetric problem of a finite orthotropic hollow cylinder, one comes closer to reality to involve the effect of axial strain than to consider the plane strain case only. However, additional mathematical difficulties should be encountered and a different solution procedure should be developed. By the separation of variables, the thermoelastic axisymmetric dynamic problem of an orthotropic hollow cylinder taking account of the axial strain is transformed to a Volterra integral equation of the second kind for a function of time, which can be solved efficiently and quickly by the interpolation method. The solutions of displacements and stresses are obtained. It is noted that the present method is suitable for an orthotropic hollow cylinder with an arbitrary thickness subjected to arbitrary axisymmetric thermal loads. Numerical comparison is made to show the effect of the axial strain on the displacements and stresses. The project supported by the National Natural Science Foundation of China (10172075) and China Postdoctoral Science Foundation (20040350712)     

Stress analysis of circumferentially corrugated hollow orthotropic cylinders

A problem-solving approach based on discrete Fourier series is used to analyze the stress state of corrugated orthotropic and transversely isotropic hollow cylinders __________ Translated from Prikladnaya Mekhanika, Vol. 42, No. 12, pp. 87–96, December, 2006.     

Influence of magnetic field on free vibrations in elastodynamic problem of orthotropic hollow sphere

The effect of magnetic field on the plane vibrations for an elastodynamic orthotropic sphere is studied. Equations of elastodynamic problems of the orthotropic hollow sphere in terms of displacement are solved. The numerical results of the frequency equations in the presence of magnetic field are discussed and shown graphically. Compar-isons are made with the result in the presence and absence of magnetic field in the case of orthotropic sphere. The results show that the effect of magnetic field is very pronounced.     

Bending problems of non-homogeneous cylindrical orthotropic circular plate

ＢＥＮＤＩＮＧＰＲＯＢＬＥＭＳＯＦＮＯＮ－ＨＯＭＯＧＥＮＥＯＵＳＣＹＬＩＮＤＲＩＣＡＬＯＲＴＨＯＴＲＯＰＩＣＣＩＲＣＵＬＡＲＰＬＡＴＥＱｉｎＳｈｅｎｇ－ｌｉ（秦圣立）（ＱｕｆｕＮｏｒｍａｌＵｎｉｃｅｒｓｉｔｙ,Ｑｕｆｕ,Ｓｈａｎｄｏｎｇ）（Ｒｅｃｅｉ...     

Thermal stresses in a rotating non-homogeneous orthotropic hollow cylinder

 In this paper the radial deformation and the corresponding stresses in a non-homogeneous hollow elastic cylinder rotating about its axis with a constant angular velocity is investigated. The material of the cylinder is assumed to the non-homogeneous and cylindrically orthotropic. The system of fundamental equations is solved by means of a finite difference method and the numerical calculations are carried out for the temperature, the components of displacement and the components of stress with the time t and through the thickness of the cylinder. The results indicate that the effect of inhomogeneity is very pronounced. Received on 21 December 2000     

An investigation of meterial properties of non-homogeneous cylindrically orthotropic circular plates

It has been been reported that the reduced stiffness of non-homogeneous cylindricallyorthotrpic circular plate varing exponentially with radius r is obtained by using thebending theory of a simple beamThe aim of this paper is to verify the effect of radius on the materal properties According to the flat stress-strain relation the values of material properties E_r E_a and v_θr which are the functions of radius r are obtained.Compared with the experimentalvalues the analytical values of the material properties are in essential agreement withtem.     

Numerical solution to the initial-boundary-value problem of electroelasticity for a radially polarized hollow piezoceramic cylinder

The paper proposes and analyzes different approaches to constructing numerical schemes to solve the nonstationary vibration problem for a radially polarized piezoelectric hollow cylinder with different electric boundary conditions under mechanical loading. It is established that when the cylinder is subjected to internal pressure, the radial displacements are similar and the longitudinal displacements substantially different in cylinders with electroded and nonelectroded surfaces __________ Translated from Prikladnaya Mekhanika, Vol. 42, No. 12, pp. 67–75, December, 2006.     

Arc-shaped interfacial crack in a non-homogeneous electro-elastic hollow cylinder with orthotropic dielectric layer

The purpose of this present work is to study the arc-shaped interfacial cracking problem in a hollow cylinder that consists of an inner orthotropic dielectric layer and an outer functionally graded piezoelectric layer. Based on the method of variable separation, the problem is reduced to a Cauchy singular integral equation, which is solved by the Lobatto-Chebyshev quadrature technique. Numerical results of the stress intensity factor are obtained and the effects of geometrical and physical quantities on the fracture parameter are surveyed in details.     

压电空心圆柱中波的传播

应用三维压电弹性体轴对称模型对压电空心圆柱中波的传播进行了研究. 发现在 圆柱中是否具有压电性质会对波的传播带来显著的差异. 当波长趋向于零时，在压电圆柱中 拟P波的波速渐进趋向于横观各向同性弹性体的准P波波速，而非压电圆柱中拟P波的波速 渐进趋向于一维杆模型中的P波波速；在压电圆柱中拟SV波存在驻波现象. 圆柱中的SH波 同电场无关，所以在压电圆柱和非压电圆柱中SH波具有相同的频散曲线. 应用积分变 换方法将圆柱的控制方程同其侧边界条件相结合，得到了一组动力学方程. 针对具体的侧边 界条件，得到相对应的波导条件和频散方程. 在此基础上通过数值计算模拟了圆柱受到端部 应力脉冲激励后的瞬态响应. 同时讨论了空心圆柱的半径比对轴向波传播的影响.     

Influence of orthotropy parameters on the stress state of hollow cylinders with elliptic cross-section

An approach based on the use of discrete Fourier series is employed to analyze the stress state of orthotropic and transversely isotropic elliptical hollow cylinders __________ Translated from Prikladnaya Mekhanika, Vol. 43, No. 12, pp. 82–90, December 2007.     

Control of stress response in a rotating infinite hollow multilayered piezoelectric cylinder

The theoretical study of the control of stress is developed for a rotating infinite hollow multilayered radially polarized piezoelectric cylinder. The exact solution is obtained by means of the state-space method. As an illustrative example, the distribution of the radial and tangential stresses in a rotating hollow internally pressurized five-layered piezoelectric cylinder subjected to different electric potential at the internal and external surfaces are performed. Numerical results show that the distribution of the stress can be controlled by applying appropriate electric potentials at the correct surfaces.     

Dynamic solution of a multilayered orthotropic piezoelectric hollow cylinder for axisymmetric plane strain problems

The dynamic solution of a multilayered orthotropic piezoelectric infinite hollow cylinder in the state of axisymmetric plane strain is obtained. By the method of superposition, the solution is divided into two parts: one is quasi-static and the other is dynamic. The quasi-static part is derived by the state space method, and the dynamic part is obtained by the separation of variables method coupled with the initial parameter method as well as the orthogonal expansion technique. By using the obtained quasi-static and dynamic parts and the electric boundary conditions as well as the electric continuity conditions, a Volterra integral equation of the second kind with respect to a function of time is derived, which can be solved successfully by means of the interpolation method. The displacements, stresses and electric potentials are finally obtained. The present method is suitable for a multilayered orthotropic piezoelectric infinite hollow cylinder consisting of arbitrary layers and subjected to arbitrary axisymmetric dynamic loads. Numerical results are finally presented and discussed.     

Double-layered piezo-thermoelastic hollow cylinder under some coupled loadings

In the present paper, a long thick-walled piezo-thermoelastic hollow cylinder with double layers is studied. The effects of temperature on the performance of the cylinder are obtained. Based on the theory of elasticity, the exact solutions of the cylinder under some coupled loadings are found. In the present paper, differences of a piezoelectric parameter between the two layers is taken into account. For comparison, numerical results have been carried out for both double-layered and graded cylinders. At the end of the present paper some discussions are addressed.     

Dynamic behavior of piezoelectric/magnetostrictive composite hollow cylinder

The dynamic behavior of a multilayered, perfectly bonded piezoelectric/magnetostrictive composite hollow cylinder under radial deformation is investigated. The superposition method, the state space method as well as the separation of variables method are elegantly integrated in the solution approach. The governing equations are finally transformed into two Volterra integral equations of the second kind with respect to two functions of time. The elastic, electric and magnetic fields are finally obtained according to solving the integral equations. Free vibrations and transient responses are demonstrated by numerical experiments.     

Stress Analysis of Orthotropic Hollow Noncircular Cylinders

The paper proposes an approach to solving three-dimensional stress problems for hollow orthotropic cylinders with noncircular cross section and certain end conditions. The approach is based on the method of separation of generatrix and directrix variables, discrete Fourier series, and the stable method of discrete orthogonalization. The results of analysis of an orthotropic cylinder are presented     

Effect of rotation in magneto-thermoelastic transversely isotropic hollow cylinder with three-phase-lag model

This article deals with the various heat source responses in a transversely isotropic hollow cylinder under the purview of three-phase-lag (TPL) generalized thermoelasticity theory. In presence of magnetic field and due to the rotating behavior of the cylinder, the governing equations are redefined for generalized thermoelasticity with thermal time delay. In order to obtain the stress, displacement and temperature field, the field functions are expressed in terms of modified Bessel functions in Laplace transformed domain. When the outer radius of hollow cylinder tends to infinity, the corresponding results are discussed. Finally an appropriate Laplace transform inversion technique is adopted.     

Modeling the effect of diffusion of the ambient medium on the long-term strength of a hollow cylinder under uniaxial tension

The problem of the long-term strength of an extended thick-walled tube containing a corrosive medium in the internal cavity is solved. The diffusion of this medium into the tube material is analyzed. The diffusion equation is solved approximately by introducing the diffusion front, and the error of the solution is estimated. The dependence of the time of fracture of the tube on the variable tensile stress and the concentration of the medium filling the cavity is obtained. __________ Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 48, No. 4, pp. 88–93, July–August, 2007.