ON THE OPTIMALITY CRITERIA FOR ARCHGRIDS.

Abstract

Recently, Rozvany and Prager obtained the minimum weight solution of a curved surface structure consisting of a dense system of intersecting arches. The study of this new class of optimal structures (termed optimal archgrids) is based on a number of assumptions. The optimality criteria derived for the archgrids are based on the simplifying assumptions that the system of arches may only run in two specified directions, and that their directions in horizontal projection must be orthogonal to each other. The writers aim to extend their formulation of the archgrid problem to cover the system of parallel arches running in any number of arbitrary directions. In addition, the optimality criteria derived also cater to the possibility of some of the arches having zero forces.