Dynamic stability of MSGT sinusoidal viscoelastic piezoelectric polymeric FG-SWNT reinforced nanocomposite plate considering surface stress and agglomeration effects under hydro-thermo-electro-magneto-mechanical loadings

چکیده مقاله

In this article, dynamic stability analysis of the viscoelastic piezoelectric polymeric nanocomposite plate reinforced by functionally graded single-walled carbon nanotubes (FG-SWNT) based on modified strain gradient theory (MSGT) is explored. The viscoelastic piezoelectric polymeric nanocomposite plate reinforced is subjected to hydrothermal and electro-magneto-mechanical loadings. The viscoelastic piezoelectric polymeric nanocomposite plate is rested on viscoelastic foundation. Uniform distribution (UD), FG-V, FG-X and FG-O distribution types are used for SWCNTs. The extended mixture approach is applied to estimation of the elastic properties. The equations of motion are derived by Hamilton's principle. These equations are solved by Navier's method. The resonance frequency or the parametric resonance is obtained then dynamic stability region is specified. There is a good agreement between the present and literature results. Various parametric investigations are performed for the influences of the small scale parameters, direct and alternating applied voltage, magnetic field, viscoelastic foundation coefficients and aspect ratios on the dynamic stability region of the viscoelastic piezoelectric polymeric nanocomposite plate. The results indicated that SWCNT agglomeration and surface stress have significant effects on the dynamic stability region and the parametric resonance. Dynamic stability region increases with increasing of thickness to width ratio, magnetic field, applied voltage, static load factor, viscoelastic foundation parameters and surface density constant, and decreasing of length to width ratio and residual surface stress constant. Also the dynamic stability region shifts to lower parameter resonance with increasing of temperature and moisture changes. The results can be employed for design of micro-electro-mechanical systems (MEMS) and nano-electro-mechanical systems (NEMS).