Axisymmetric thermal postbuckling of functionally graded graphene nanocomposite annular plates with various geometric imperfections.

This paper presents the axisymmetric thermal postbuckling analysis of functionally graded graphene platelets-reinforced composite (FG-GPLRC) annular plates with various geometric imperfections within the framework of first-order shear deformation theory and von Kármán geometric nonlinearity. An imperfection model composed of trigonometric and hyperbolic functions is used to simulate possible imperfections with different shapes, amplitudes and locations. The 3D Halpin–Tsai model is employed to estimate the effective modulus of graphene nanocomposites. Nonlinear governing equations are derived by the variational principle and are then solved by the generalized differential quadrature method combined with the modified Newton–Raphson iteration. Parametric studies are conducted to highlight the influences of imperfection amplitude, localization degree, location and half-wave number on the thermal postbuckling behaviour of FG-GPLRC annular plates. It is found that the thermal postbuckling resistance is reduced due to the existence of geometric imperfections, and this effect become more/less significant as the imperfection amplitude/half-wave number increases. • Thermal postbuckling of FG-GPLRC annular plates with geometric imperfections is investigated for the first time. • The 3D Halpin–Tsai model is introduced to evaluate the elastic modulus of 3D-random graphene nanocomposites. • Thermal postbuckling resistance is more weakened by the global imperfections than the localized ones. • Thermal postbuckling behaviour is less sensitive to the imperfections with a smaller amplitude or more half-waves. [ABSTRACT FROM AUTHOR]