Buckling of Sandwich Plates with Random Material Properties Using Improved Plate Model

An improved higher-order zigzag plate theory in a random environment is proposed and it is implemented in a stochastic finite element framework to study the buckling characteristic of sandwich plates with random material properties. The theory satisfies transverse shear stress continuity at all of the layer interfaces and the transverse shear-stress-free condition at the top and bottom surfaces. It also includes the effect of transverse deformability to the core. The through-thickness variation of in-plane displacements is assumed to be cubic, whereas transverse displacement varies quadratically within the core and it remains constant over the face sheets. Note that sandwich and composite structures are characterized by inherent uncertainties in their material properties. The effect of these uncertainties on the buckling characteristic of sandwich plates is studied by modeling the macromechanical material properties as basic random variables. A stochastic finite element method consisting of an efficient C-0 finite element in conjunction with a mean-centered first-order perturbation approach is developed, and the model is employed to evaluate the second-order statistics of the buckling loads. The published results are used to validate the deterministic part of the proposed approach, and its stochastic component is validated with an independent Monte Carlo simulation.