The size dependent large displacement behavior of planar microbeams and microframes is studied in this paper using a corotational beam element. To account for the effect, modified couple stress theory (MCST) employed conjunction with Euler-Bernoulli deriving internal force vector tangent stiffness matrix Newton-Raphson based iterative procedure used combination arc-length method to solve nonlin...

Abstract The size dependent static pull-in instability of functionally graded (FG) microbeams in micro-electromechanical systems (MEMS) is studied, considering the influence axial force. material properties are varied beam thickness by a power-law function, and they calculated rule mixture. To account for microsize effect, classical Euler-Bernoulli theory employed combination with modified coup...

In this paper, the effect of magnetic field on double-diffusive convection in couple-stress fluid saturating a porous medium is considered. By applying linear stability theory and normal mode analysis method, a necessary condition is derived which states that the viscoelastic double-diffusive convection at marginal state, cannot manifest as stationary convection if the thermal Rayleigh number R...

The thermosolutal instability of couple-stress fluid in the presence of uniform vertical rotation is considered. Following the linearized stability theory and normal mode analysis, the dispersion is obtained. For the case of stationary convection, the stable solute gradient and rotation have stabilizing effects on the system, whereas the couple-stress has both stabilizing and destabilizing effe...

In this paper, an analytical model based on the modified couple stress theory and Timoshenko beam is developed to study vibrational power flow of a microbeam with crack. The open edge crack modeled as rotational spring, which connects two segments separated by location. governing equations cracked are derived from Hamilton's principle. By introducing differential operator method, transformed in...

The localization of elastic wave at defect in phononic crystals (PnCs) has been applied to design piezoelectric energy harvesting (PEH) devices. However, the earlier researches were based on classical linear elasticity theory, which failed predict structural behavior micron scale. Based a modified couple stress theory (MCST) and mixed finite element method, physics builder COMSOL® Multiphysics ...

The objective is to study the deformation in a homogeneous isotropic modified couple stress thermoelastic rotating medium in the presence of Hall current and magnetic field due to a ramp-type thermal source. The generalized theories of thermoelasticity developed by Lord Shulman (L-S, 1967) and Green Lindsay (G-L, 1972) are used to investigate the problem. Laplace and Fourier transform technique...

In this research, wave propagation analysis in polymeric smart nanocomposite micro-tubes reinforced by single-walled carbon nanotubes (SWCNT) conveying fluid is studied. The surrounded elastic medium is simulated by visco-Pasternak model while the composite micro-tube undergoes electro-magneto-mechanical fields. By means of micromechanics method, the constitutive structural coefficients of nano...