The purpose of this paper is to investigate the bending, buckling, vibration analyses of microcomposite circular-annular sandwich plate with CNT reinforced composite facesheets under hydro-thermo-magneto-mechanical loadings are presented using first order shear deformation theory (FSDT) and modified strain gradient theory (MSGT) that includes three material length scale parameters. Also, an isotropic homogeneous core is considered for microcomposite circular-annular sandwich plate. The generalized rule of mixture is employed to predict mechanical, moisture and thermal properties of microcomposite sandwich plate. By using Hamilton's principle, governing equations are solved by differential quadrature method (DQM) for a circular annular sandwich plate. The predicted results are validated by carrying out the comparison studies for the FGM plates by modified couple stress theory (MCST). The obtained results are given to indicate the influence of the material length scale parameter, core-to-facesheet thickness ratios, magnetic effect, thermal and moisture effects on the dimensionless deflection, critical buckling load, and natural frequency of microcomposite circular sandwich plate. The results can be employed in solid-state physics, materials science, nano-electronics, and nano electro-mechanical devices such as microactuators, and microsensor.

In this article, dynamic stability of annular sandwich plate with carbon nanotubes reinforced composite facesheets and an isotropic homogeneous core are presented based on first-order shear deformation theory and modified strain gradient theory. The generalized rule of mixture is employed to predict mechanical properties of microcomposite sandwich plate. The equations of motion are derived from Hamilton’s principle and solved by differential quadrature method. The fast rate of convergence of the method is shown and the results are compared against existing results in the literature. The results indicate that volume fraction of carbon nanotubes in facesheets and dimensionless length scale parameter has significant effects on the dynamic stability region and the parametric resonance. Dynamic stability region increases with considering of dimensionless length scale parameter, increasing of volume fraction of carbon nanotubes, and static load factor. Also, the influence of inner-to-outer radius ratios, radius-to-thickness ratios, and core-to-facesheets ratios are considered. The results can be employed for design of materials science, in junction high pressure micropipe connections, solid-state physics, micro-electro-mechanical systems, and nano electromechanical systems such as microactuators and microsensor.

The buckling analysis of circular annular plate reinforced by carbon nanotubes (CNTs) subjected to compressive and torsional loads with various axially symmetric boundary conditions are studied in this paper. The developed model is based on the classical laminated plate theory (CLPT). The Mori‐Tanaka method is employed to calculate the effective elastic modulus of composites having aligned oriented straight CNTs. The eigenvalues of the problem are obtained by means of an analytical approach based on the optimized Rayleigh‐Ritz method. The effects of CNTs orientation angles, edge conditions, geometric ratio of plate and agglomeration of the randomly oriented straight CNTs are investigated on the critical buckling loads. Extensive studies validity of the results based on available data have been carried out prior to the presentation of salient results of this analysis. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers

In this research, the dynamic stability of the double-bonded annular sandwich microplate is investigated. Face sheets are made from composite materials reinforced by carbon nanotubes in which mechanical properties are obtained by the extended rule of the mixture. Also, the core layer is made from a honeycomb aluminum which is defined by the geometric parameters of the unit cell and mechanical properties of the virgin core material. The equations of motion are derived from Hamilton’s principle and solved by the differential quadrature method (DQM) based on higher order shear deformation theory (HSDT) and modified couple stress theory (MCST). The results are compared with the obtained results by the other literature to examine the accuracy of the present formulation. The dynamic stability of the double-bonded annular sandwich microplate with hexagonal honeycomb core including variations of core thickness, inclined angle, and aspect ratio of the unit cell are discussed. Also, the effects of motion direction of the structure, viscoelastic foundation, material length scale parameter, volume fractions of CNTs in face sheets, and the core thickness to total thickness ratio on dynamic instability region are presented.