Stability of functionally graded graphene-reinforced composite laminated thick plates in thermal environment

Considering the excellent physical properties, graphene can be regarded as an ideal reinforcing material for composite structures today. Nevertheless, the existing higher-order models neglecting the continuity conditions of interlaminar stresses may lose capability to analyze precisely the stability of functionally graded graphene-reinforced composite (FG-GRC) laminated thick plates. For FG-GRC laminated structures, the compatibility conditions of interlaminar stresses will directly affect the accuracy of critical loads. As a result, an appealing plate theory with only seven unknowns is suggested for buckling analysis of FG-GRC laminated thick plates. The compatibility requirements of interlaminar shear stresses between adjacent layers are satisfied in the proposed model. Improved transverse shear stresses are obtained using a preprocessing approach based on the three-dimensional (3D) equilibrium equation and Reissner's mixed variational theorem (RMVT). The performance of the suggested model is assessed by using the 3D elasticity solutions and the results obtained from some existing models. Numerical results indicate that the proposed model can reliably predict critical loads of laminated and sandwich plates. Additionally, the impact of the graphene distribution pattern, staking sequence, volume fraction, boundary conditions, thermal environment, and geometric parameters of the plate on the buckling behavior of FG-GRC laminated plates is explored.