Structures that have thin cross-sections and are prone to compressive loads may
buckle suddenly at critical load values. To calculate the critical buckling load,
researchers have reported many analytical solutions which are related mainly to the
deterministic approach. However, the important geometric and material parameters
highly affect critical buckling loads of structures and they should be considered as
uncertain in order to obtain realistic estimations. This is due to the fact that
imperfections in the geometry and material properties may occur during the
production stages of a component or under operational conditions. In the present
study, which is based on first-order shear deformation theory (FSDT), in the first
step the deterministic buckling equation of symmetric sandwich composite plates
consisting of two identical carbon/epoxy skins and a foam core between the
skins is formulated considering the uncertainties which can occur in the
nondeterministic state. In the next step, closed-form analytical buckling
equations including the geometric and material uncertainties are derived using
the convex modeling and Lagrange multiplier method and based on the
worst-case scenario leading to the lowest buckling loads. Sensitivity analysis is
also conducted to understand which uncertain parameters have the most
negative effect on the critical buckling load. Finite element analysis (FEA) is
implemented to validate the derived equations. It is seen that even minor variations
in the material properties and geometric dimensions lead to considerable
variations in the critical buckling load. The significance of involving the
uncertainty in the analysis is explained both qualitatively and quantitatively.