Double-Layered Piezothermoelastic Hollow Cylinder under Thermal Loading

2006 ◽  
Vol 302-303 ◽  
pp. 684-692 ◽  
Author(s):  
Ying Chen ◽  
Zhifei Shi

In the present paper, a long thick-walled piezothermoelastic hollow cylinder under a symmetric thermal loading is studied. Based on the theory of elasticity, the mechanical and electrical as well as the thermal fields of the cylinder are obtained. Besides, the effects of both temperature change and the material difference between two layers on the mechanical responses and electric output of the cylinder are investigated in detail. For comparison, some discussions of numerical results are addressed at the end of this paper.

2004 ◽  
Vol 261-263 ◽  
pp. 651-656 ◽  
Author(s):  
Z.S. Shao ◽  
L.F. Fan ◽  
Tie Jun Wang

Analytical solutions of stress fields in functionally graded circular hollow cylinder with finite length subjected to axisymmetric pressure loadings on inner and outer surfaces are presented in this paper. The cylinder is simply supported at its two ends. Young's modulus of the material is assumed to vary continuously in radial direction of the cylinder. Moreover, numerical results of stresses in functionally graded circular hollow cylinder are appeared.


Author(s):  
Yaser Kiani ◽  
Mostafa Mirzaei

In this research, post-buckling response of sandwich beams with carbon nanotube reinforced face sheets subjected to uniform temperature rise loading and resting on a two-parameter elastic foundation is investigated. A single-layer theory formulation based on the first-order shear deformation beam theory is used. Material properties of the media are obtained according to a refined rule of mixtures approach which contains efficiency parameters. Suitable for the large deformations, von-Kármán strains are taken into consideration. The elastic foundation is modelled as the Pasternak model which takes into account the shear interaction of the springs. Material properties of the face sheets are considered to be position and temperature dependent. The governing equations of the system are obtained using the Ritz method for various combinations of clamped, simply supported and sliding supported edges. Post-buckling equilibrium path of the beam is obtained according to an iterative displacement control strategy. Numerical results of the present study are compared with the available data in the open literature. Then, the numerical results are provided to explore the effect of side-to-thickness ratio, volume fraction of carbon nanotube, distribution pattern of carbon nanotube, the ratio of face thickness-to-host thickness, boundary conditions and elastic foundation.


2019 ◽  
Vol 11 (06) ◽  
pp. 1950053 ◽  
Author(s):  
M. Saadatfar

In this paper, an analytical method is presented for the problem of the time-dependent response of a functionally graded magneto–electro–elastic (FGMEE) rotating hollow cylinder in thermal environment. The material properties of FGMEE are supposed to be power-law functions of radius. Applying the equations of equilibrium and electrostatic and magnetostatic equations, a differential equation which includes creep strains is achieved. At first, an exact solution for the primitive stresses, electric and magnetic potentials are achieved by eliminating creep strains in the mentioned differential equation. Then, Prandtl–Reuss equations, as well as Norton’s law, are employed for the FGMEE. Now, creep stress rates can be achieved by considering only creep strains in the mentioned differential equation. As a final step, time-dependent creep stress, electric potential and magnetic potential redistributions at any time can be achieved using an iterative method. Numerical examples are presented to disclose the influence of creep evolution, thermal loading, angular velocity and grading index on the primitive and creep response of the FGMEE hollow cylinder. Results show that the enhancement in tensile hoop stress during the creep evolution must be considered in designing. So, the creep analysis is vital to have more reliable and accurate aerospace smart structures.


2006 ◽  
Vol 79 (2) ◽  
pp. 233-248 ◽  
Author(s):  
J. M. Horton ◽  
G. E. Tupholme

Abstract Closed-form expressions are derived for the torsional stiffness, radial stiffness and tilting stiffness of annular rubber flanged bushes of finite length in three principal modes of deformation, based upon the classical theory of elasticity. Illustrative numerical results are deduced with realistic physical data of typical flanged bushes.


1990 ◽  
Vol 112 (1) ◽  
pp. 16-23 ◽  
Author(s):  
J. W. Eischen ◽  
C. Chung ◽  
J. H. Kim

A classic paper by Timoshenko in 1925 dealt with thermal stresses in bimetal thermostats and has been widely used for designing laminated structures, and in contemporary studies of stresses in electronic devices. Timoshenko’s analysis, which is based on strength of materials theory, is unable to predict the distribution of the interfacial shear and normal stresses known to exist based on more sophisticated analyses involving the theory of elasticity (Bogy (1970) and Hess (1969)). Suhir (1986) has recently provided a very insightful approximate method whereby these interfacial stresses are estimated by simple closed-form formulas. The purpose of the present paper is to compare three independent methods of predicting the interfacial normal and shear stresses in bimaterial strips subjected to thermal loading. These are: 1.) Theory of elasticity via an eigenfunction expansion approach proposed by Hess, 2.) Extended strength of materials theory proposed by Suhir, 3.) Finite element stress analysis. Two material configurations which figure prominently in the electronics area have been studied. These are the molydeneum/aluminum and aluminum/silicon material systems. It has been discovered that when the two layers are nearly the same thickness, the approximate methods adequately predict the peak values of the interfacial stresses but err in a fundamental manner in the prediction of the distribution of stress. This may not be of concern to designers who are interested mainly in maximum stress alone. However, it has been shown that if one layer is relatively thin compared to the other, the approximate methods have difficulty in predicting both the peak value of stress and its associated distribution.


2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
Manish Bhandari ◽  
Kamlesh Purohit

Functionally graded materials (FGMs) are one of the advanced materials capable of withstanding the high temperature environments. The FGMs consist of the continuously varying composition of two different materials. One is an engineering ceramic to resist the thermal loading from the high-temperature environment, and the other is a light metal to maintain the structural rigidity. In the present study, the properties of the FGM plate are assumed to vary along the thickness direction according to the power law distribution, sigmoid distribution, and exponential distribution. The fundamental equations are obtained using the first order shear deformation theory and the finite element formulation is done using minimum potential energy approach. The numerical results are obtained for different distributions of FGM, volume fractions, and boundary conditions. The FGM plate is subjected to thermal environment and transverse UDL under thermal environment and the response is analysed. Numerical results are provided in nondimensional form.


1972 ◽  
Vol 94 (1) ◽  
pp. 201-209 ◽  
Author(s):  
D. W. Childs

The objective of the analysis which follows is the derivation of simulation models for flexible rotating equipment such as turbine rotors. The analysis employed is based on relatively simple concepts of vector mechanics and results in a “lumped-parameter” simulation model. The basic simulation model is simplified by invoking the small-deflection assumptions of the theory of elasticity. It is then restated in terms of a non-body-fixed (nonspinning) coordinate system. Methods for modeling bearing constraints and the applicability of eigenanalaysis are discussed. Representative numerical results are provided for a simulation of the Mark 15-F turbopump of the J-2 engine system.


Author(s):  
Hamid Mahmoudi ◽  
Gholamali Atefi

The aim of this article is to obtain a comprehensive analytical solution for thermal stresses in a hollow cylinder, subjected to periodic time-varying thermal loading on the inner circular and insulated outer circular surfaces, where both lateral surfaces are kept at constant temperature. Temperature distribution as a function of time, and radial, and longitudinal directions is analytically solved using Fourier series and the resulting thermal stresses are obtained. The proposed method is very comprehensive and covers many theoretical and practical problems. The results for both temperature field and thermal stresses have been compared with those obtained in the former works and show excellent agreement for the same conditions.


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