CAD of Truss Structures by the Interactive Simplex Method
The Interactive Simplex method which is a method developed for solving multiobjective problems in man-machine interactive mode is applied in a CAD system for optimal truss design. The method is mainly based on the Simplex method, which is one of the representative direct search methods. The techniques of minimum comparison sorting and minimum merging are applied in the method to make the requirement from the designer to be only the preference judgement of two alternatives at a time. The method is implemented as part of the CAD system. The CAD system mainly consists of optimization and graphics display subsystems. In the optimization subsystem there are Equilibrium Linear Programming and Stress Ratio method programs in addition to the Interactive Simplex method program. The graphics display subsystem shows structural models with their relevant information and converging process of the Interactive Simplex method in order to facilitate the difficulty in making decision. Applicable problems can have single or multiple objective functions. An optimal design of a bridge truss with multiple objective functions is given to illustrate the desigh procedure using the proposed CAD system.
KeywordsOptimal Topology Truss Structure Member Size Multiple Objective Function Vertical Member
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- V. Wuwongse, “Multiobjective optimization by interactive pairwise comparison,” Doctoral dissertation, Dept. of Systems Science, Tokyo Inst. of Technology, 1982.Google Scholar
- J. A. Neider and R. Mead, “A simplex method for function minimization,” Comput. J., Vol. 7, pp. 308–313, 1965.Google Scholar
- E. Somekh and U. Kirsch, “Interactive optimal design of truss structures,” CAD, Vol. 13, pp. 253–259, 1981.Google Scholar
- R. H. Gallagher and O. C. Zienkiewiez, Optimum Structural Design, Theory and Applications, John Wiley, pp. 19–26, 1973.Google Scholar