798. An Energy Criteria and a Search Procedure for Automated Design of Minimum Weight Structures

Paper

Abstract

A minimum weight design algorithm, based on a strain energy criteria is presented. The matrix displacement method of analysis is used in the development of the method. The energy criteria is coupled with a linear interpolation search technique to increase the scope of the method in the presence of displacement constraints in addition to stress constraints. When there are only stress constraints the design based on the energy criteria gives a minimum weight structure. In the presence of displacement constraints the design is carried in two stages. The first stage is based on the energy algorithm while the second stage is based on a search procedure. A discussion of various instability considerations and their effect on limiting stresses is presented. Examples of three dimensional bar structures with both fixed and variable stress constraints are presented to illustrate the effectiveness of the method. Reliability and computational efficiency are the significant features of this approach.