Effect of nonlinear elastic foundation on large amplitude free and forced vibration of functionally graded beam

2014 ◽  
Vol 115 ◽  
pp. 60-68 ◽  
Author(s):  
A.S. Kanani ◽  
H. Niknam ◽  
A.R. Ohadi ◽  
M.M. Aghdam
Keyword(s):  
Elastic Foundation ◽  
Forced Vibration ◽  
Large Amplitude ◽  
Functionally Graded ◽  
Functionally Graded Beam ◽  
Nonlinear Elastic Foundation ◽  
Nonlinear Elastic

Large amplitude flutter analysis of functionally graded carbon nanotube reinforced composite plates with piezoelectric layers on nonlinear elastic foundation

2017 ◽  
Vol 233 (2) ◽  
pp. 533-544 ◽  
Author(s):  
Ali A Yazdi
Keyword(s):  
Carbon Nanotube ◽  
Elastic Foundation ◽  
Large Amplitude ◽  
Composite Plates ◽  
Functionally Graded ◽  
Governing Equations ◽  
Nonlinear Elastic Foundation ◽  
Reinforced Composite ◽  
Piezoelectric Layers ◽  
Nonlinear Elastic

This paper presents a study of geometrical nonlinear flutter of functionally graded carbon nanotube-reinforced composite plates embedded with piezoelectric layers subjected to supersonic flow on nonlinear elastic foundation. The governing equations of the system are obtained using the classical plate theory and von Karman geometric nonlinearity. The linear piston theory is utilized to evaluate the aerodynamic pressure. Galerkin method is used to reduce the governing equations to an ordinary differential equation with respect to time in the form of Duffing equation. The homotopy perturbation method is employed to study the effect of large amplitude on the nondimensional flutter pressure. It is assumed that carbon nano-tubes are distributed along thickness in two different manners namely uniform distribution and functionally graded. The effects of volume fraction of carbon nanotubes, large amplitude, different distribution types, piezoelectric layers, and applied voltage on flutter pressure are studied.

Nonlinear thermomechanical buckling of sandwich FGM oblique stiffened plates with nonlinear effect of elastic foundation

2020 ◽  
pp. 089270572093595
Author(s):  
Dang Thuy Dong ◽  
Vu Hoai Nam ◽  
Nguyen Thoi Trung ◽  
Nguyen Thi Phuong ◽  
Vu Tho Hung
Keyword(s):  
Elastic Foundation ◽  
Geometrical Nonlinearity ◽  
Shear Deformation Theory ◽  
Equation System ◽  
External Pressure ◽  
Functionally Graded ◽  
Geometrical Properties ◽  
Nonlinear Elastic Foundation ◽  
The Galerkin Method ◽  
Nonlinear Elastic

In this article, the nonlinear thermomechanical buckling behaviors of sandwich functionally graded plates subjected to an axial compression and external pressure are analytically analyzed resting on nonlinear elastic foundation. Assuming that the plates are reinforced by oblique stiffeners and rested on nonlinear elastic foundation. The formulations are established using the higher-order shear deformation theory taking into account the geometrical nonlinearity of von Kármán. The Lekhnitskii’s smeared stiffener technique is developed for shear deformable oblique stiffener system using the coordinate transformation technique with both mechanical and thermal terms. The Galerkin method is utilized to obtain the nonlinear algebraically equation system, then, solve it to determine the explicit expressions of critical buckling loads and postbuckling load–deflection curves. Numerical results show the effects of temperature, nonlinear elastic foundation, stiffeners, and material and geometrical properties on nonlinear behaviors of plates.

Nonlinear Static and Dynamic Buckling Analyses of Imperfect FGP Cylindrical Shells Resting on Nonlinear Elastic Foundation Under Axial Compression

2020 ◽  
Vol 20 (07) ◽  
pp. 2050074
Author(s):  
Kamran Foroutan ◽  
Habib Ahmadi
Keyword(s):  
Elastic Foundation ◽  
Axial Compression ◽  
Cylindrical Shells ◽  
Dynamic Buckling ◽  
Functionally Graded ◽  
Porosity Distribution ◽  
Nonlinear Elastic Foundation ◽  
Special Cases ◽  
Nonlinear Static ◽  
Nonlinear Elastic

In this paper, semi-analytical and analytical methods for the nonlinear static and dynamic buckling analyses of imperfect functionally graded porous (FGP) cylindrical shells subjected to axial compression are presented. The structure is embedded within a generalized nonlinear elastic foundation, treated as a two-parameter Winkler–Pasternak foundation augmented by a nonlinear cubic stiffness. The material property of the shell changes continuously through the thickness. Two types of FGP distributions, i.e. uniform porosity distribution (UPD) and nonuniform porosity distribution (NPD), are considered. By applying the Galerkin’s method to the von Kármán equations, the buckling of the shells was solved. The fourth-order Runge–Kutta method is utilized to obtain the responses of nonlinear dynamic buckling (NDB). The results obtained for some special cases are compared with those available elsewhere. The effects of various geometrical properties, material parameters and elastic foundation coefficients are investigated on the nonlinear static buckling (NSB) and dynamic buckling (DB) analyses of the shells. It was shown that various types of porosity, imperfection and the elastic foundation parameters have a strong effect on the buckling behaviors of the FGP cylindrical shells.

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