Advertisement

CAD of Truss Structures by the Interactive Simplex Method

  • Vilas Wuwongse
  • Mahendra Narayan Nagraj

Abstract

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.

Keywords

Optimal Topology Truss Structure Member Size Multiple Objective Function Vertical Member 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. [1]
    V. Wuwongse, “Multiobjective optimization by interactive pairwise comparison,” Doctoral dissertation, Dept. of Systems Science, Tokyo Inst. of Technology, 1982.Google Scholar
  2. [2]
    J. A. Neider and R. Mead, “A simplex method for function minimization,” Comput. J., Vol. 7, pp. 308–313, 1965.Google Scholar
  3. [3]
    E. Somekh and U. Kirsch, “Interactive optimal design of truss structures,” CAD, Vol. 13, pp. 253–259, 1981.Google Scholar
  4. [4]
    L. R. Ford and S. M. Johnson, “A tournament problem,” Am. Math. Monthly, Vol. 66, pp. 387–389, 1959.MathSciNetMATHCrossRefGoogle Scholar
  5. [5]
    F. K. Hwang and S. Lin, “A simple algorithm for merging two disjoint linearly ordered sets,” SIAM J. Computing, Vol. 1, pp. 31–39.MathSciNetCrossRefGoogle Scholar
  6. [6]
    K. F. Reinschmidt and A. D. Russel, “Applications of Linear Programming in Structural Layout and Optimization,” Comput. Struct., Vol 4, pp. 855–869, 1974.CrossRefGoogle Scholar
  7. [7]
    R. H. Gallagher and O. C. Zienkiewiez, Optimum Structural Design, Theory and Applications, John Wiley, pp. 19–26, 1973.Google Scholar

Copyright information

© Plenum Press, New York 1985

Authors and Affiliations

  • Vilas Wuwongse
    • 1
  • Mahendra Narayan Nagraj
    • 1
  1. 1.Division of Computer ApplicationsAsian Institute of TechnologyBangkokThailand

Personalised recommendations