Application of the Created Response Surface Technique to Structural Optimization
Abstract
The Created Response Surface Technique was applied to some problems of structural optimization with multi-load conditions. The constrained optimization problem was converted to an unconstrained problem by the use of penalty functions that varied inversely with the distance of the design point from a constraint. Response surfaces also were introduced for optimization with discrete variables. The Rosenbrock Method of unconstrained optimization was used. The original method was modified to take advantage of the interaction between the optimization procedure and the response of the structure to change in discrete sections. This, when coupled with the r extrapolation procedure, resulted in considerable savings in computing time. To quantitatively evaluate the effectiveness of the techniques presented, a pilot computer program for the optimization of small-scale structures was developed. To minimize the effort involved in the development of the program a relatively inefficient analysis module was selected from a previously coded computer program. This analysis was limited to approximately 50 degrees of freedom and originally contained only an axial force member in the element library. This was considered sufficient for initial research. Two problems were investigated, that of the 3-bar truss studied by Schmit and Mallett and that of the 25-bar truss studied by Fox and Schmit. Fox and Schmit included buckling constraints and used tube diameter and thickness as the design variables. The cross-sectional areas of the circular tubes are used here as the design variables. The Euler criteria are included as stress limits for each member.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1968
- Accession Number
- ADA446772
Entities
People
- Pedro V. Marcal
- Ronald A. Gellatly
Organizations
- Brown University