Postbuckling of nanotube-reinforced composite cylindrical panels resting on elastic foundations subjected to lateral pressure in thermal environments

2016 ◽  
Vol 122 ◽  
pp. 174-183 ◽  
Author(s):  
Hui-Shen Shen
2017 ◽  
Vol 21 (8) ◽  
pp. 2816-2845 ◽  
Author(s):  
Nguyen D Duc ◽  
Ngo Duc Tuan ◽  
Phuong Tran ◽  
Tran Q Quan ◽  
Nguyen Van Thanh

This study follows an analytical approach to investigate the nonlinear dynamic response and vibration of eccentrically stiffened sandwich functionally graded material (FGM) cylindrical panels with metal–ceramic layers on elastic foundations in thermal environments. It is assumed that the FGM cylindrical panel is reinforced by the eccentrically longitudinal and transversal stiffeners and subjected to mechanical and thermal loads. The material properties are assumed to be temperature dependent and graded in the thickness direction according to a simple power law distribution. Based on the Reddy’s third-order shear deformation shell theory, the motion and compatibility equations are derived taking into account geometrical nonlinearity and Pasternak-type elastic foundations. The outstanding feature of this study is that both FGM cylindrical panel and stiffeners are assumed to be deformed in the presence of temperature. Explicit relation of deflection–time curves and frequencies of FGM cylindrical panel are determined by applying stress function, Galerkin method and fourth-order Runge-Kutta method. The influences of material and geometrical parameters, elastic foundations and stiffeners on the nonlinear dynamic and vibration of the sandwich FGM panels are discussed in detail. The obtained results are validated by comparing with other results in the literature.


2019 ◽  
Vol 8 (1) ◽  
pp. 582-596 ◽  
Author(s):  
Le Thi Nhu Trang ◽  
Hoang Van Tung

Abstract Nonlinear stability of nanocomposite spherical and cylindrical panels reinforced by carbon nanotubes (CNTs), resting on elastic foundations and subjected to uniform external pressure in thermal environments is investigated in this paper. CNTs are embedded into matrix phase through uniform distribution (UD) or functionally graded (FG) distribution, and effective properties of CNT-reinforced composite are estimated through an extended rule of mixture. Governing equations are based on classical shell theory taking geometrical nonlinearity, initial geometrical imperfection and panel-foundation interaction into consideration. Approximate solutions of deflection and stress functions are assumed to satisfy simply supported boundary conditions and Galerkin method is applied to obtain nonlinear load-deflection relation. Numerical examples show the effects of volume fraction and distribution type of CNTs, in-plane condition of edges, curvature of panel, thermal environments, elastic foundations and imperfection size on the nonlinear response and snap-through instability of the curved panels. The present study reveals that efficiency of CNT distribution type depends on curvature of panel and in-plane behavior of boundary edges, and bifurcation type buckling response of pressure-loaded panels may occur at elevated temperature.


2018 ◽  
Vol 33 (2) ◽  
pp. 153-179 ◽  
Author(s):  
Le Thi Nhu Trang ◽  
Hoang Van Tung

This article investigates the nonlinear stability of composite cylindrical panels (CPs) reinforced by carbon nanotubes (CNTs), resting on elastic foundations and subjected to combined thermomechanical loading conditions. CNTs are embedded into matrix phase through uniform distribution or functionally graded distribution. Material properties of constituents are assumed to be temperature dependent and effective elastic moduli of carbon nanotube–reinforced composite are estimated by the extended rule of mixture. Nonlinear governing equations of geometrically imperfect panels are based on first-order shear deformation theory accounting for elastic foundations and tangential constraint of straight edges. Analytical solutions are assumed to satisfy simply supported boundary conditions and closed-form expressions relating load and deflection are derived through Galerkin method. Numerical examples show the effects of preexisting nondestabilizing loads, distribution patterns, panel curvature, in-plane condition of unloaded edges, thermal environments, initial imperfection, and elastic foundations on the nonlinear stability of nanocomposite CPs under combined loading conditions.


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