Optimum design of thick sandwich plates for minimum interlaminar stress

A mixed finite element scheme in conjunction with the quasi-Newton optimization technique is proposed for optimum design of the thick sandwich plates for minimum interlaminar stress. The accuracy of the mixed finite element scheme is doubly checked by comparing the present results with the solutions of Pagano and Srinivas-Rao obtained from the three dimensional elasticity approach. A rectangular thick sandwich plate with simply-supported (SS) or clamped edges (CC), subjected to three types of transverse loads (i. e., sinusoidally distributed, uniformly distributed and central point loads) is considered to be the numerical examples. The effects of parameters, the thickness ratio between core-layer and face-layers, modulus ratio, aspect ratio and span-to-thickness ratio, on the optimal fiber orientations of face-layers are discussed.