scholarly journals Geometrically Nonlinear Transversal Vibrations of Corrugated Cylindrical Shells

2018 ◽  
Vol VI(186) (22) ◽  
pp. 61-63
Author(s):  
M. V. Marchuk ◽  
T. V. Goriachko ◽  
V. S. Pakosh ◽  
O. F. Lesyk
Author(s):  
Francesco Pellicano

In the present paper vibrations of circular cylindrical shells having different boundary conditions are analyzed. Sanders-Koiter theory is considered for shell modeling: both linear and nonlinear vibrations are analyzed. An energy approach based on Lagrange equations is considered; a mixed expansion of displacement fields, based on harmonic functions and Tchebyshev polynomials, is applied. Several boundary conditions are analyzed: simply supported, clamped-clamped, connection with rigid bodies. Comparisons with experiments and finite element analyses show that the technique is capable to model several and complex boundary conditions. Applications to geometrically nonlinear shells show that the technique is effective also in the case of nonlinear vibration: comparisons with the literature confirm the accuracy of the approach.


2020 ◽  
pp. 107754632098246
Author(s):  
Majid Khayat ◽  
Abdolhossein Baghlani ◽  
Seyed Mehdi Dehghan ◽  
Mohammad Amir Najafgholipour

This article investigates the influence of graphene platelet reinforcements and nonlinear elastic foundations on geometrically nonlinear dynamic response of a partially fluid-filled functionally graded porous cylindrical shell under exponential loading. Material properties are assumed to be varied continuously in the thickness in terms of porosity and graphene platelet reinforcement. In this study, three different distributions for porosity and three different dispersions for graphene platelets have been considered in the direction of the shell thickness. The Halpin–Tsai equations are used to find the effective material properties of the graphene platelet–reinforced materials. The equations of motion are derived based on the higher-order shear deformation theory and Sanders’s theory. Displacements and rotations of the shell middle surface are approximated by combining polynomial functions in the meridian direction and truncated Fourier series with an appropriate number of harmonic terms in the circumferential direction. An incremental–iterative approach is used to solve the nonlinear equations of motion of partially fluid-filled cylindrical shells based on the Newmark direct integration and Newton–Raphson methods. The governing equations of liquid motion are derived using a finite strip formulation of incompressible inviscid potential flow. The effects of various parameters on dynamic responses are investigated. A detailed numerical study is carried out to bring out the effects of some influential parameters, such as fluid depth, porosity distribution, and graphene platelet dispersion parameters on nonlinear dynamic behavior of functionally graded porous nanocomposite partially fluid-filled cylindrical shells reinforced with graphene platelets.


Author(s):  
Caitri´ona de Paor ◽  
Denis Kelliher ◽  
Kevin Cronin ◽  
William M. D. Wright

The buckling capacity of thin cylindrical shells subject to uniform external pressure is investigated in this paper. Thin cylindrical shells are known to be highly sensitive to geometric and material imperfections such as wall thickness variation, non-circularity and random geometric imperfections. The effect of imperfection on the buckling load is studied using finite element (FE) models and laboratory experiments. Imperfection measurements are taken on small scale steel cans and these measurements are modelled and analysed using a geometrically nonlinear static finite element analysis. The cans are then tested in the laboratory and the results compared with those predicted by the FE models and theory.


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