Free vibration analysis of deep doubly curved sandwich panels

Abstract This paper presents the free vibration analysis of doubly curved open deep sandwich shells made of thin outer layers and a relatively thick core. The outer layers are assumed to be made of high strength and high density material. The core is a low strength low density material. The Rayleigh–Ritz method, in which the displacement fields are defined by Bezier surface patches, is used to obtain the natural frequencies. The formulation procedure is developed for the analysis of open panels circumscribed by four curvilinear edges. Numerical results are obtained for circular cylindrical and spherical sandwich panels with the boundary conditions given by: one curved edge clamped and the remaining three edges free as well as two opposite edges clamped and the other two completely free.