Free vibration and stability analysis of stiffened sandwich plates

Description is given of the development of a B-spline finite strip method for predicting the natural frequencies of vibration and the buckling stresses of rectangular sandwich panels. Each panel comprises a flat sandwich main plate which is reinforced by a number of longitudinal compact plate stiffeners attached to the faceplates. The core of the main plate is represented as a three-dimensional solid whilst the faceplates and the stiffening plates may in general be composite laminates which are represented, in turn, as either shear-deformable plates or classically thin plates. Details are given of the development of the elastic stiffness, geometric stiffness and consistent mass matrices of the finite strip models. The nature of the structural equations and the sophisticated procedure for their solution are discussed. Both vibrational and buckling applications of the developed analysis capability are presented and these include situations in which the corresponding mode shapes are of an overall nature and, for some of the buckling problems, of a highly localised nature.