Stochastic Free Vibration Response of Soft Core Sandwich Plates Using an Improved Higher-Order Zigzag Theory.

In this paper, an improved higher-order zigzag theory for vibration of soft core sandwich plates with random material properties is proposed. The theory satisfies the condition of continuity in transverse shear stresses at all the layer interfaces and transverse shear stress free condition at the top and bottom of the plate, including the transverse flexibility effect of the core. The variation of in-plane displacements through thickness is assumed to be cubic while transverse displacement varies quadratically within the core and constant throughout the faces. The core is modeled as a 3D elastic continuum. An efficient C0 finite element in conjunction with a first-order perturbation approach is developed for the implementation of the proposed plate theory in a random environment and is employed to evaluate the second-order statistics of the eigensolutions by modeling lamina material properties as basic random variables. The mean and standard deviations of natural frequencies and their mode shapes are computed and validated with Monte Carlo simulation. [ABSTRACT FROM AUTHOR]