Sandwich Panels with Stepped Facings

Sandwich panels have been developed to either design a lighter structure capable of carrying prescribed loads or to increase the load-carrying capacity subject to limitations on the weight. The major loadcarrying elements of a sandwich structure are its facings, while the core primarily serves to resist transverse shear loads, enhance local strength and stability of the facings, and combine two facings into a single structural system. The facings being subject to bending and in-plane tensile/compressive loads and to in-plane shear, their strength and stiffness are paramount to the sandwich structure. In the present paper we investigate advantages of so-called “stepped” facings with geometry modified to locally enhance the strength and stiffness at strategically important locations with a minimum effect on the weight. We illustrate that sandwich designs with stepped facings can be attractive in static problems concerned with strength and stability, while their advantage in situations where it is necessary to increase the fundamental frequency of the panel is less pronounced.