Minimum-weight design of sandwich shells subjected to fixed and moving loads

Abstract

This paper is concerned with the minimum-weight design of sandwich shells. The core thickness is known and the thickness of the face sheets, which are composed of a perfectly plastic material, is to be determined. For the case of a single set of loads acting on a plate, a procedure for obtaining the absolute minimum volume of the face sheets was given by Drucker and Shield [1], minimum volume coinciding with minimum weight for homogeneous materials. The procedure was later extended to the design of shells by Shield [2] and then to the case of multiple loading [3], that is when the structure is required to support separately two or more systems of loads. Independently Gross and Prager [4] have obtained the minimum-weight design of a beam under a single concentrated moving load and recently Save and Prager [5] extended this procedure to beams subjected simultaneously to fixed and moving loads. It was found that in some cases a superposition method could be used.