Thermo-mechanical postbuckling analysis of sandwich cylindrical panels with functionally graded auxetic GRMMC core supported by elastic foundations

Abstract

Modelling and analysis of compressive and thermal postbuckling of sandwich cylindrical panels supported by an elastic foundation are presented in this paper. The sandwich cylindrical panel is composed of auxetic graphene-reinforced metal matrix composite (GRMMC) core with negative Poisson's ratio (NPR) and two metal face sheets. Two cases of the compressive postbuckling of auxetic sandwich cylindrical panels under axial compression in thermal environments and the thermal postbuckling of auxetic sandwich cylindrical panels caused by uniform temperature rise are considered. In the GRMMC core, the volume fraction of graphene through the thickness domain is arranged as a piece-wise functionally graded (FG) pattern. The material properties of both metal face sheets and the GRMMC core are assumed to be temperature dependent. The governing equations of the auxetic sandwich cylindrical panels are formulated based on the framework of the Reddy's third order shear deformation theory. The von Kármán-type kinematic nonlinearity, the thermal effect, the panel-foundation interaction and the initial geometric imperfection of the panel are also taken into account. The postbuckling solutions are obtained by employing a singular perturbation technique along with a two-step perturbation approach. The effects of the FG pattern, the face sheet-to-core-to-face sheet thickness ratio, and foundation stiffness on the postbuckling behavior of sandwich cylindrical panels with FG auxetic GRMMC core are studied in detail.