In-plane free vibrations of circular beams made of functionally graded material in thermal environment: Beam theory approach

2015 ◽  
Vol 122 ◽  
pp. 217-228 ◽  
Author(s):  
Ugurcan Eroglu
Author(s):  
Vu Hoai Nam ◽  
Nguyen Thi Phuong ◽  
Dang Thuy Dong ◽  
Nguyen Thoi Trung ◽  
Nguyen Van Tue

In this paper, an analytical approach for nonlinear buckling and post-buckling behavior of stiffened porous functionally graded plate rested on Pasternak's elastic foundation under mechanical load in thermal environment is presented. The orthogonal and/or oblique stiffeners are attached to the surface of plate and are included in the calculation by improving the Lekhnitskii's smeared stiffener technique in the framework of higher-order shear deformation plate theory. The complex equilibrium and stability equations are established based on the Reddy's higher-order shear deformation plate theory and taken into account the geometrical nonlinearity of von Kármán. The solution forms of displacements satisfying the different boundary conditions are chosen, the stress function method and the Galerkin procedure are used to solve the problem. The good agreements of the present analytical solution are validated by making the comparisons of the present results with other results. In addition, the effects of porosity distribution, stiffener, volume fraction index, thermal environment, elastic foundation… on the critical buckling load and post-buckling response of porous functionally graded material plates are numerically investigated.


2013 ◽  
Vol 560 ◽  
pp. 157-180 ◽  
Author(s):  
Ahmad Akbari Rahimabadi ◽  
Sundararajan Natarajan ◽  
Stephane Pa Bordas

In this paper, the effect of a centrally located cutout (circular and elliptical) and cracksemanating from the cutout on the free flexural vibration behaviour of functionally graded materialplates in thermal environment is studied. The discontinuity surface is represented independent of themesh by exploiting the partition of unity method framework. A Heaviside function is used to capturethe jump in the displacement across the discontinuity surface and asymptotic branch functions areused to capture the singularity around the crack tip. An enriched shear flexible 4-noded quadrilateralelement is used for the spatial discretization. The properties are assumed to vary only in the thicknessdirection. The effective properties of the functionally graded material are estimated using the Mori-Tanaka homogenization scheme and the plate kinematics is based on the first order shear deformationtheory. The influence of the plate geometry, the geometry of the cutout, the crack length, the thermalgradient and the boundary conditions on the free flexural vibration is numerically studied.


2017 ◽  
Vol 21 (3) ◽  
pp. 895-916 ◽  
Author(s):  
Sid Ahmed Belalia

In this paper, the geometrically nonlinear formulation based on von Karman’s assumptions is employed to study the large amplitude free vibrations of functionally graded materials sandwich plates. The functionally graded material sandwich plate is made up of two layers of power-law functionally graded material face sheet and one layer of ceramic homogeneous core. A hierarchical finite element is employed to define the model, taking into account the effects of the transverse shear deformation and the rotatory inertia. The equations of motion for the nonlinear vibration of the functionally graded material sandwich plates are obtained using Lagrange’s equations. Employing the harmonic balance method, the equations of motion are converted from time domain to frequency domain and then solved iteratively using the linearized updated mode method. Results for linear and nonlinear frequency parameters of the simply supported functionally graded material sandwich plates are computed and compared with the published values, and an excellent agreement was found. The influence of the mechanical properties of the functionally graded material, thickness ratio of FGM layers, and volume fraction exponent on the backbone curves and on the nonlinear frequency parameters are investigated. The effects of the material properties of two different types of ceramics on the large amplitude vibration behaviors of the functionally graded material sandwich plates is also presented and discussed for the first time.


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