BUCKLING AND BENDING ANALYSIS OF FG-GRC PLATES USING HIGH-ORDER SHEAR DEFORMATION PLATE THEORIES

Based on the third-order shear deformation plate theory (TSDPT) and sinusoidal shear deformation plate theory (SSDPT), the buckling and bending behaviors of functionally graded graphene-reinforced composite (FG-GRC) plates were investigated. By comparing the calculated results with the first-order shear deformation plate theory (FSDPT), the differences among TSDPT, SSDPT and FSDPT in the buckling and bending mechanical behaviors of FG-GRC plates were analyzed. The effective Young's modulus is estimated using the modified Halpin-Tsai model, and the effective Poisson's ratio is determined using the rule of mixtures. The governing equations containing five unknown quantities are derived using the principle of minimum potential energy, and the analytical solutions in Navier form for the bending deflection and critical buckling load of simply supported FG-GRC rectangular plates are obtained. Numerical results show that: Compared with TSDPT and SSDPT, FSDPT significantly overestimates the critical buckling load and significantly underestimates the bending deflection of FG-X type FG-GRC plate, and slightly underestimates the critical buckling load and slightly overestimates the bending deflection of FG-O type FG-GRC plate, while the calculated results of UD type and FG-A type FG-GRC plate are almost identical using the three theories; The results of TSDPT and SSDPT are very similar in calculating the bending deflection and critical buckling load of FG-GRC plates; When the total number of layers N_L of the plate is less than 10~15, the variation of the ratio of bending load and the ratio of critical buckling load is significant. When N_L exceeds 10~15, The variation of these two ratios become small; Due to the extremely high modulus of elasticity of graphene nanoplatelets (GPLs), the weight fraction f_G of GPLs in FG-GRC plates is positively correlated with the capability of the plates to resist bending and buckling.