Examination of thermal postbuckling of temperature dependent FG-GRMMC laminated beams with negative Poisson's ratio on elastic foundations

This paper examines the in-plane negative Poisson's ratio (NPR) effect on the thermal postbuckling of graphene-reinforced metal matrix composite (GRMMC) laminated beams subjected to a uniform temperature rise and supported by an elastic foundation. GRMMC layers having different graphene volume fractions can facilitate the formation of functionally graded (FG) patterns of the beams. The temperature-dependent material properties of GRMMC layers can be estimated by a nonlinear function of temperature from the results of the molecular dynamics simulations. The governing equations for the beam thermal postbuckling problem can be derived based on a higher order shear deformation beam theory and solved by applying the two-step perturbation approach. The von Kármán geometric nonlinearity, the elastic foundation support and the thermal effect are considered in the modeling. Numerical investigations are carried out for (10/-10/10/-10/10)_S and (10/-10/10)_S GRMMC beams with in-plane NPR. The results show that the buckling temperature of (10/-10/10)_S UD beam is slightly higher than that of (10/-10/10/-10/10)_S UD beam. The thermal postbuckling capacity for the (10/-10/10)_S FG-X beam becomes much higher than that of the (10/-10/10/-10/10)_S FG-X beam, when the beam deflection is sufficiently large.