Study and control of thermoelastic damping of in-plane vibration of the functionally graded nano-plate

2019 ◽  
Vol 25 (23-24) ◽  
pp. 2850-2862 ◽  
Author(s):  
Zaher Rahimi ◽  
Wojciech Sumelka ◽  
Samrand Rash Ahmadi ◽  
Dumitru Baleanu

The phenomenon of thermoelastic damping (TED) is a well-known mechanism of structural damping in which a vibrating thermoelastic structure obeys energy dissipation caused by the irreversible heat conduction in its volume. TED can be listed as common intrinsic losses and it cannot be controlled as easily as extrinsic losses thus this subject appears to be a very attractive research field. In this study TED of in-plane vibration of a functionally graded material (FGM) nano-plate has been studied based on the Eringen nonlocal theory. The effects of main parameters such as ambient temperature, length, and width of the nano-plate, the nonlocal parameter and the material gradient on the quality factor (Q) have been investigated. Also, the effect of different combinations of ceramic and metal in an FGM plate on increasing Q and subsequently reduction of the dissipated energy due to thermal effects has been illustrated.

2017 ◽  
Vol 24 (17) ◽  
pp. 3809-3818 ◽  
Author(s):  
Farzad Ebrahimi ◽  
Mohammad Reza Barati ◽  
Parisa Haghi

The present research deals with the wave dispersion behavior of a rotating functionally graded material (FGMs) nanobeam applying nonlocal elasticity theory of Eringen. Material properties of rotating FG nanobeam are spatially graded according to a power-law model. The governing equations as functions of axial force due to centrifugal stiffening and displacements are obtained by employing Hamilton’s principle based on the Euler–Bernoulli beam theory. By using an analytical model, the dispersion relations of the FG nanobeam are derived by solving an eigenvalue problem. Numerical results clearly show that various parameters, such as angular velocity, gradient index, wave number and nonlocal parameter, are significantly effective to characteristics of wave propagations of rotating FG nanobeams. The results can be useful for next generation study and design of nanomachines, such as nanoturbines, nanoscale molecular bearings and nanogears, etc.


2020 ◽  
Vol 865 ◽  
pp. 67-71
Author(s):  
Shi Rong Li ◽  
Peng Xiong ◽  
Da Fu Cao

In this paper, thermoelastic damping (TED) in a simply supported rectangular functionally graded material (FGM) micro plate with continuous variation of the material properties along the thickness direction is performed. The equations of motion and the heat conduction equation coupled with the thermal effects are derived based on the Mindlin plate theory and the one-way coupled heat conduction theory, respectively. The heat conduction equation with variable coefficients is solved by using the layer-wise homogenization approach. Analytical solution of TED is obtained by complex frequency method. Numerical results of TED are presented for the rectangular FGM micro plate made of ceramic-metal constituents with the power-law gradient profile. The effects of the shear deformation, the material gradient index, the plate thickness on the TED of the FGM micro plate are studied.


2008 ◽  
Vol 56 ◽  
pp. 188-193
Author(s):  
Daniela Marinova

The paper reviews the modelling of intelligent structures and the control of a low energy active system. The structure composite couples functionally graded material and longitudinally piezoelectric fibre reinforced composite for actuating. Active control based on feedback concept is considered for shape regulating. The problem for optimal selection of the actuators number and locations is considered. Numerical simulations are presented.


2019 ◽  
Vol 25 (21-22) ◽  
pp. 2769-2783 ◽  
Author(s):  
Arian Bahrami ◽  
Ali Zargaripoor ◽  
Hamidreza Shiri ◽  
Nima Khosravi

According to the present literature review, the axial vibration of the axially functionally graded (FG) tapered nanorod with attached nonlinear spring has not been addressed so far. In this study, the axial vibration of the FG tapered nanorod is studied based on Eringen’s nonlocal theory, in which one end of the nanorod is clamped and the other end is attached to a nonlinear spring and a nanoparticle. The influence of different parameters such as the nonlinear spring constant, mass of the nanoparticle, and the nonlocal parameter on the natural frequencies is presented in detail. The solutions via Tables can be utilized as a reliable reference for evaluating the validity of future researches. The presented nonlocal solutions can be helpful for those who are interested in designing micro/nano electromechanical systems.


Author(s):  
Ismail Bensaid ◽  
Ahmed Amine Daikh ◽  
Ahmed Drai

The investigation conducted in this paper aims to study free vibration and buckling behaviors of size-dependent functionally graded sandwich nanobeams. In order to take into account the small size effects, nonlocal elasticity theory of Eringen's is incorporated. Material properties of the functionally graded sandwich beams are supposed to change continuously through the thickness direction according to two forms of the volume fraction of constituents by power law functionally graded material and sigmoid law functionally graded material. These rules are modified to consider the effect of porosity, which covers four kinds of porosity distributions. Two types of sandwich nanobeams were provided: (a) homogeneous core and functionally graded skins and (b) functionally graded core and homogeneous skins. Third-order shear deformation theory without any shear correction factor in conjunction with Hamilton's principle is used to extract the governing equations of motions of porous functionally graded sandwich nanobeams and then solved analytically for two hinged ends. The effects of nonlocal parameter, length to thickness ratios, material graduation index, amount of porosity, porosity distribution shape, on the nondimensional frequency and critical buckling load of the functionally graded sandwich nanobeams made of porous materials are exhibited by a parametric study.


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