Stochastic perturbation-based finite element for deflection statistics of soft core sandwich plate with random material properties

The effect of random variations in material properties of laminated sandwich plates on the transverse deflections is investigated. An improved higher-order plate model is proposed earlier by the authors, which satisfies the transverse shear stress continuity conditions at the layer interfaces including the zero transverse shear stress conditions at the plate top and bottom surfaces. The theory assumes the variation of in-plane displacements to be cubic with discontinuities in the transverse shear strains at the layer interfaces, while the transverse displacements varies quadratically across the core thickness, thereby including transverse normal deformation of the soft core. The core is considered to behave as a 3-D elastic medium. To obtain the second-order statistics of deflections of sandwich plate, a stochastic C0 finite element (FE) based on the first-order perturbation technique is developed, where the lamina properties are considered as basic random variables while the other system properties are assumed to be deterministic. The performance of the improved stochastic laminated sandwich model is demonstrated through comparison of mean and standard deviations (SDs) of deflections obtained through independent Monte Carlo simulations and by comparison with results available in literature.