The spectral problem of thin elastic shells in membrane approximation does not satisfy the classical properties of compactness and so there exists an essential spectrum. In the first part, we propose to determinate this spectrum and the weakness directions in the shell. We particularly study the case of homogeneous and isotropic shells with some examples. In the second part, we consider an elem...

Structural optimization using computational tools has become a major research field in recent years. The paper deals with a sizing optimization analysis of laminated circular cylindrical shell. For thin-walled shells, the classical shell theory is capable of accurately predicting the shell behavior. The weight minimization subjected to displacement constraint within the numerical optimization o...

in this study, thermo-mechanical nonlinear vibration of a polyethylene (pe) cylindrical shell embedded in an elastic foundation was investigated. the shell is reinforced by armchair carbon nanotubes (cnts) where characteristics of the equivalent composite being determined using mori-tanaka model. the elastic medium is simulated using the spring constant of the winkler-type,  . employing nonline...

In this study, discrepancies between the free vibration of fiber-metal laminate (FML) and composite cylindrical shells reinforced by carbon nanotubes (CNTs) based on Love’s first approximation shell theory have been considered by beam modal function model. The representative volume elements consist of three and four phases for composite and FML structures, respectively, which include fiber, CNT...

Buckling and post buckling of cylindrical shells under hydrostatic pressure is regarded as important issue in structure of submarines. These cylindrical shells have variable thickness due to construction process which effected by pressure of buckling and its destruction. In this paper, effects of changing thickness on buckling and destruction pressure under external hydrostatic pressure of a sh...

ABSTRACT Fluid-loaded nested cylindrical shells are modelled using a doubled-walled cylindrical shell structure closed at each end by circular end plates and excited by a transverse force at one end. The effects of various influencing factors on the radiated sound power are examined corresponding to non-concentricity of the cylindrical shells, entrained fluid and rib connections in the annular ...

The vibro-acoustic characteristics of cylindrical shell are widely studied because of its strong engineering application background, especially when the shell is immersed in infinite fluid field or partially immersed. In the present paper, the method for analyzing sound radiation of semi-submerged finite cylindrical shell with antisymmetric velocity distribution is first proposed. The orthogona...

In this paper, the vibration of composite cylindrical shell with piezoelectric layers in the interior and exterior surfaces is investigated. The composite shell without piezoelectric layers can be studied and compared the results with the results of other researchers, the cylindrical shell laminated with layers of piezoelectric vibration checked. The result is a three-dimensional elasticity equ...

In this article, the axisymmetric mechanical buckling of thin cylindrical shell made of functionally graded material (FGM) is considered. The governing equations for a thin cylinder based on the first-order shell theory and Timoshenko's assumptions are obtained. The equations are derived using the Sanders simplified kinematic relations and the principle of work and energy. The constituent mater...