ANALYSIS AND DESIGN OF SANDWICH PLATES WITH INSERTS - A HIGH-ORDER SANDWICH PLATE-THEORY APPROACH

Sandwich structures are very susceptible to failure due to local stres s concentrations induced in areas of load introduction, supports, geom etrical and material discontinuities. These local stress concentration s are caused by localised bending effects, where the individual face s heets tend to bend about their own middle surface rather than about th e middle surface of the sandwich. This paper deals with such local eff ects seen around inserts in structural sandwich plates. A high-order t heory for bending of sandwich plates, developed and adapted especially for the purpose of studying sandwich plates with inserts and other '' hard points'', is introduced. The theory, which accounts for the trans verse flexibility of the core material, includes separate descriptions of the face sheets and the core materials as well as general specific ation of loads and boundary conditions. The theory is formulated in te rms of first-order partial differential equations, which are solved nu merically using the ''multi-segment method of integration''. Examples involving sandwich plates with ''through-the-thickness'' inserts subje cted to axisymmetric and non-axisymmetric external loading are present ed. The paper is concluded by a discussion of design aspects. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.