nonlinear dynamic analysis of annular fg porous sandwich plates reinforced by graphene platelets

In this paper, the nonlinear dynamic analysis of porous annular sandwich plates reinforced with graphene platelets (gpls) under different boundary conditions is investigated. the gaussian random field (grf) alongside with halpin-tsai micromechanics model are used for the variational poisson’s ratio and effective material property of the gpls which are distributed in two forms of symmetric and non-symmetric patterns with different porosity dispersion models. using von-karman nonlinear relations and different plate theories, the time-dependent governing equations are obtained and then solved using the dynamic relaxation (dr) method combined with implicit newmark’s integration technique. finally, some key elements namely: gpl weight fractions and distributions, porosity coefficients and dispersions, different loadings, boundary conditions, and the effects of thickness-to-radius ratio are discussed in detail. the results show that with an increase in porosity, the difference between the results of fsdt and mhsdt greatens. also, a significant increase in plate stiffness is observed by adding a small amount of gpl to the porous core of the sandwich plate.