Volume 18, Issue 6, 2009

ELASTIC STABILITY ANALYSIS OF A TWO-LAYERED FUNCTIONALLY GRADED CYLINDRICAL SHELL UNDER AXIAL COMPRESSION WITH THE USE OF ENERGY APPROACH

H. Sepiani^1,*, A. Rastgoo¹, M. Ahmadi², A.Ghorbanpour Arani, K. Sepanloo²,

¹ Department of Mechanical Engineering, Faculty of Engineering, University of Tehran, Tehran, I. R. Iran
² School of Research and Development of Nuclear Reactors and Accelerators, Nuclear Science and Technology Institute, Tehran, I. R. Iran
³ Department of Mechanical Engineering, Faculty of Engineering, University of Kashan, Kashan, I. R. Iran

* Author to whom correspondence should be addressed E-mail: sepiani@ut.ac.ir

Received 26 August 2009; accepted 20 October 2009

ABSTRACT
This paper investigates the elastic axisymmetric buckling of a thin, simply supported functionally graded (FG) cylindrical shell embedded with an elastic layer under axial compression. The analysis is based on energy method and simplified nonlinear strain-displacement relations for axial compression. Material properties of functionally graded cylindrical shell are considered graded in the thickness direction according to a power-law distribution in terms of the volume fractions of the constituents. Using minimum potential energy together with Euler equations, equilibrium equations are obtained. Consequently, stability equation of functionally graded cylindrical shell with an elastic layer is acquired by means of minimum potential energy theory and Trefftz criteria. Another analysis is made using the equivalent properties of FG material. Numerical results for stain¬less steel-ceramic cylindrical shell and aluminum layer are obtained and critical load curves are analyzed for a cylindrical shell with an elastic layer. A comparison is made to the results in the literature. The results show that the elastic stability of functionally graded cylindrical shell with an elastic layer is dependent on the material composition and FGM index factor, and the shell geometry parameters and it is concluded that the application of an elastic layer increases elastic stability and significantly reduces the weight of cylindrical shells.

Keywords: Functionally Graded Material (FGM); Buckling; Stability; Two-layered Functionally Graded Cy-lindrical Shell (FGCS)