共查询到20条相似文献,搜索用时 31 毫秒
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The propagation of waves in microstretch thermoelastic homogeneous isotropic plate subjected to stress free thermally insulated and isothermal conditions is investigated in the context of conventional coupled thermoelasticity (CT) and Lord and Shulman (L–S) theories of thermoelasticity. The secular equations for both symmetric and skew-symmetric wave mode propagation have been obtained. At short wavelength limits, the secular equations for symmetric and skew-symmetric modes reduce to Rayleigh surface wave frequency equation. The amplitudes of dilatation, microrotation, microstretch and temperature distribution for the symmetric and skew symmetric wave modes are computed analytically and presented graphically for different theories of thermoelasticity. The theoretical and numerical computations are found to be in close agreement. 相似文献
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Hamdy M. Youssef 《Archive of Applied Mechanics (Ingenieur Archiv)》2006,75(8-9):553-565
This paper presents the problem of thermoelastic interactions in an elastic infinite medium with cylindrical cavity at an
elevated temperature field arising out of a ramp-type heating and loading bounding surface of the cavity, and the surface
is assumed initially quiescent. The governing equations are taken in a unified system from which the field equations for coupled
thermoelasticity as well as for generalized thermoelasticity can be easily obtained as particular cases. Due attention has
been paid to the finite time of rise of temperature, stress, displacement, and strain. The problem has been solved analytically
using a direct approach. The derived analytical expressions have been computed for a specific situation. Numerical results
for the temperature distribution, thermal stress, displacement, and strain are represented graphically. A comparison is made
with the results predicted by the three theories. 相似文献
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The present paper is aimed at studying the effect of rotation on the general model of the equations of generalized thermo-microstretch for a homogeneous isotropic elastic half-space solid whose surface is subjected to a Mode-I Crack problem considered. The problem is in the context of the generalized thermoelasticity Lord-?hulman??s (L-S) theory with one relaxation time, as well as the classical dynamical coupled theory (CD) The normal mode analysis is used to obtain the exact expressions for the displacement components, force stresses, temperature, couple stresses and microstress distribution. The variations of the considered variables through the horizontal distance are illustrated graphically. Comparisons are made with the results in the presence and absence of rotation and in the presence and absence of microstretch constants between the two theories. 相似文献
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Ahmed E. Abouelregal 《Meccanica》2013,48(7):1731-1745
In this paper, the induced temperature, displacement, and stress fields in an infinite transversely isotropic unbounded medium with cylindrical cavity due to a moving heat source and harmonically varying heat are investigated. This problem is solved in the context of the linear theory of generalized thermoelasticity with dual phase lag model. The governing equations are expressed in Laplace transform domain. Based on Fourier series expansion technique the inversion of Laplace transform is done numerically. The numerical estimates of the displacement, temperature and stress are obtained and presented graphically. The theories of coupled thermoelasticity, generalized thermoelasticity with one relaxation time, and thermoelasticity without energy dissipation can extracted as special cases. Some comparisons have been shown in figures to present the effect of the heat source, dual phase lags parameters and the angular frequency of thermal vibration on all the studied fields. 相似文献
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Ibrahim A. Abbas 《Archive of Applied Mechanics (Ingenieur Archiv)》2009,79(1):41-50
In this paper, we constructed the equations of generalized magneto-thermoelasticity in a perfectly conducting medium. The
formulation is applied to generalizations, the Lord–Shulman theory with one relaxation time, and the Green–Lindsay theory
with two relaxation times, as well as to the coupled theory. The material of the cylinder is supposed to be nonhomogeneous
isotropic both mechanically and thermally. The problem has been solved numerically using a finite element method. Numerical
results for the temperature distribution, displacement, radial stress, and hoop stress are represented graphically. The results
indicate that the effects of nonhomogeneity, magnetic field, and thermal relaxation times are very pronounced. In the absence
of the magnetic field or relaxation times, our results reduce to those of generalized thermoelasticity and/or classical dynamical
thermoelasticity, respectively. Results carried out in this paper can be used to design various nonhomogeneous magneto-thermoelastic
elements under magnetothermal load to meet special engineering requirements.
An erratum to this article can be found at 相似文献
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Ibrahim A. Abbas 《基于设计的结构力学与机械力学》2015,43(4):501-513
The model of generalized thermoelasticity proposed by dual phase lag (DPL), is applied to study the thermoelastic interactions in an infinite fiber-reinforced anisotropic medium with a circular hole. A decaying with time thermal field on the boundary of the hole, which is stress free, causes the thermoelastic interactions. The solutions for displacement, temperature, and stresses are obtained with the help of the finite element procedure. The effects of the reinforcement on temperature, stress, and displacement are studied. The exact solution in the case of isotropic medium is discussed explicitly. The accuracy of the finite element method validated by comparing between the finite element and exact solutions for absence the reinforcement. 相似文献
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S. M. Abo-Dahab 《Meccanica》2012,47(3):613-620
The present work is devoted to study effects of the thermally induced vibration, magnetic field and viscoelasticity in an
isotropic homogeneous unbounded body with a spherical cavity. The GN model of thermoelasticity without energy dissipation is applied. The closed form solutions for distributions of displacement,
temperature and radial and hoop stresses are illustrated. The boundary conditions for the temperature and mechanical and Maxwell’s
stresses are employed. The solutions valid in the case of small frequency are deduced and the results are compared with the
corresponding results obtained in other generalized thermoelasticity theories. The results obtained are calculated for a copper
material and presented graphically. It’s deduced that the magnetic field, viscosity and thermally induced vibration are very
pronounced on displacement, temperature and stresses. 相似文献
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The present investigation is concerned with an axi-symmetric problem in the electromagnetic micropolar thermoelastic half-space whose surface is subjected to the mechanical or thermal source. Laplace and Hankel transform techniques are used to solve the problem. Various types of sources are taken to illustrate the utility of the approach. Integral transforms are inverted by using a numerical technique to obtain the components of stresses, temperature distribution, and induced electric and magnetic fields. The expressions of these quantities are illustrated graphically to depict the magnetic effect for two different generalized thermoelasticity theories, i.e., Lord and Shulman (L-S theory) and Green and Lindsay (G-L theory). Some particular interesting cases are also deduced from the present investigation. 相似文献
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The propagation of plane waves in fibre-reinforced, rotating thermoelastic half-space proposed by Lord-Shulman is discussed.
The problem has been solved numerically using a finite element method. Numerical results for the temperature distribution,
the displacement components and the thermal stress are given and illustrated graphically. Comparisons are made with the results
predicted by the coupled theory and the theory of generalized thermoelasticity with one relaxation time in the presence and
absence of rotation and reinforcement. It is found that the rotation has a significant effect and the reinforcement has great
effect on the distribution of field quantities when the rotation is considered. 相似文献
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直接有限元法求解广义磁热弹二维旋转问题 总被引:1,自引:0,他引:1
为了验证直接有限元法求解广义磁热弹耦合旋转问题的有效性及准确性,该文基于Lord和Shulman(L-S)广义热弹性理论,采用直接有限元方法,求解了置于磁场中的旋转半无限大体受热冲击作用的动态响应问题.文中给出了L-S型广义磁热弹耦合旋转问题的控制方程,建立了L-S型广义磁热弹旋转问题的虚位移原理,推导得到了相应的有限... 相似文献
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Ibrahim A. Abbas Abo-el-nour N. Abd-alla 《Archive of Applied Mechanics (Ingenieur Archiv)》2008,78(4):283-293
Thermoelastic interactions in an infinite orthotropic elastic medium with a cylindrical cavity are studied. The cavity surface
is subjected to ramp-type heating of its internal boundary, which is assumed to be traction free. Lord–Shulman and Green–Lindsay
models for the generalized thermoelasticity theories are selected since they allow for second-sound effects and reduce to
the classical model for an appropriate choice of the parameters. The temperature, radial displacement, radial stress, and
hoop stress distributions are computed numerically using the finite-element method (FEM). The results are presented graphically
for different values of the thermal relaxation times using the three different theories of generalized thermoelasticity. Excellent
agreement is found between the finite-element analysis and analytical and classical solutions. 相似文献
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This paper presents an investigation of temperature, displacement, stress, and induced magnetic field in a half space perfectly-conductive plate. Finite element equations regarding generalized magneto-thermoelasticity problems with two relaxation times (i.e., the G-L theory) are derived using the principle of virtual work. For avoiding numerical complication involved in inverse Laplace and Fourier transformation and low precision thereof, the equations are solved directly in time-domain. As a numerical example, the derived equation is used to investigate the generalized magneto-thermoelastic behavior of a semi-infinite plate under magnetic field and subjecting to a thermal shock loading. The results demonstrate that FEM can faithfully predict the deformation of the plate and the induced magnetic field, and most importantly can reveal the sophisticated second sound effect of heat conduction in two-dimensional generalized thermoelastic solids, which is usually difficult to model by routine transformation methods. A peak can be observed in the distribution of stress and induced magnetic field at the heat wave front and the magnitude of the peak decreases with time, which can not be obtained by transformation methods. The new method can also be used to study generalized piezo-thermoelastic problems.The project supported by the National Natural Science Foundation of China (10132010 and 10472089)The English text was polished by Yunming Chen 相似文献
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<正>The model of equations of micropolar generalized magneto-thermoelasticity is introduced within the context of the theory of two temperatures generalized thermoelasticity and we consider a problem of an isotropic homogeneous micropolar medium taking into account the heat effects and allowing the magnetic field effects.A plane wave analysis is employed to obtain the exact formulas of the two temperatures(conductive and mechanical),displacement components, micro-rotation components,stresses,couple stresses,induced electric current,electric field and magnetic field.Arbitrary application is chosen to enable us to get the complete solution.The considered variables are presented graphically and discussions are made for the results. 相似文献
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Based on the Lord and Shulman generalized thermoelasticity theory with one relaxation time, an isotropic semi-infinite plate subjected to a moving heat source has been studied by employing the finite element method directly in time domain, whose distributions of nora dimensional temperature, displacement and stress are illustrated graphically. The results show that the present method is an effective and exact numerical one for solving the thermoelastic coupling problem and is capable of overcoming the defects of traditional integrated transformation and inverse integrated transformation methods. At the same time, the temperature step of the thermal wave front is obtained exactly in contrast with conventional numerical transformation methods. 相似文献
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AbstractEnlightened by the Caputo fractional derivative, the present study deals with a novel mathematical model of generalized thermoelasticity to investigate the transient phenomena due to the influence of magnetic field and moving heat source in a rod in the context of three-phase lag (TPL) theory of thermoelasticity. Both ends of the rod are fixed and heat insulated. Employing Laplace transform as a tool, the problem has been transformed into the space-domain and solved analytically. Finally, solutions in the real-time domain are obtained by applying the inverse Laplace transform. Numerical calculation for stress, displacement, and temperature within the rod is carried out and displayed graphically. The effect of moving heat source speed on temperature, stress, and temperature is studied. It is found from the distributions that the temperature, thermally induced displacement and stress of the rod are found to decrease at large source speed. For the better understanding of the effect of moving heat source on all the distributions, three animations are added. 相似文献
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《International Journal of Solids and Structures》2007,44(13):4243-4255
The present paper is aimed at studying the effects of rotation on the thermoelastic interaction in an infinite Kelvin–Voigt-type viscoelastic, thermally conducting plate rotating about the normal to its faces with uniform angular velocity. This facilitates the decoupling of anti-plane/in-plane motion which is not possible, in general. The upper and lower surfaces of the plate are subjected to stress-free, thermally insulated or isothermal conditions. The formulation is applied according to three theories of the generalized thermoelasticity: Lord-Shulman with one relaxation time, Green–Lindsay with two relaxation times, as well as the coupled theory. Secular equations are derived for the plate in closed form isolated mathematical conditions for symmetric and skew-symmetric wave mode propagation in completely separate terms. In the absence of mechanical relaxations (Rotation and viscous effects), the results for generalized and couple theories of thermoelasticity were obtained as particular cases from the derived secular equations. In the absence of thermomechanical coupling, the analysis for a viscoelastic plate can be deduced from the present one. Finally the numerical solution is carried out for copper material. The function iteration numerical scheme is used to solve the complex secular equations, in order to obtain phase velocity and attenuation coefficients of propagating wave mode. The dispersion curves and attenuation coefficients profiles so obtained for symmetric and skew-symmetric wave modes are presented graphically to illustrate and compare the theoretical results in the presence and absence of rotation. The study may be useful in the construction and design of gyroscopes and rotation sensors as well as in the application in diverse fields. 相似文献
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The asymptotic solution of the three-dimensional dynamic of coupled thermoelasticity problem (with the mutual influence of the strain and temperature fields taken into account) for an isotropic rectangular plate is used to perform a comparative analysis of the results obtained according to this theory and the theory of temperature stresses. The parameters whose values affect the applicability of these theories and of the applied theory used to solve quasistatic problems of thermoelasticity are obtained. 相似文献