Analytical Investigation of Buckling Behavior in Bi-curved GPLs-reinforced Sandwich Composite Shells with Cellular Core

Abstract

This study investigates axial buckling of sandwich composite shells with anti-tetrachiral lattice cores and graphene-reinforced surfaces, analytically deriving mechanical properties for GPL distributions: uniform (UD), V-pattern (FG-V), and X-pattern (FG-X). The fundamental formulas are formed utilizing Reddy higher-order shear deformation theory (HSDT) and minimize the total potential energy principle. The Navier solution tactic is employed to extract the characteristic equation of the system, which is subsequently resolved to calculate the critical buckling load for different geometric and mechanical parameter configurations. The results reveal that volume fraction and distribution of GPLs significantly influence the buckling load, with optimal performance being contingent upon the geometric constraints of the lattice core. By optimizing the lattice core specifications, the highest buckling load can be achieved with minimal GPL volume fraction, enhancing the economic feasibility of nanoparticle usage in such structures. Notably, the FG-V distribution with a 0.05 wt.% GPL demonstrates the most efficient configuration for maximizing the buckling load. The results emphasize the importance of optimizing the geometry of the lattice core to achieve the maximum buckling load. Specifically, for a lattice configuration with R_x/R_y = 1.5, the optimal inclination angle of 10° leads to a 0.8% increase in buckling load compared to other angles. Similarly, for R_x/R_y = 1, the highest buckling load is obtained at an inclination angle of 60°, which is approximately 30% greater than the minimum buckling load observed. These findings highlight the critical role of geometric optimization in maximizing the structural stability and performance of bi-curved sandwich composite shells.