OPTIMAL DESIGN OF 16 BAR TRUSS STRUCTURE BY PATTERN SEARCH METHODS

Abstract

The focus of this research was to formulate optimization model of 16-bar trusses
along with stress, stability and deflection constraints. The derivative free methods were used for the
optimization of engineering design problems. These methods were basically designed for
unconstrained optimization problems. In formulated optimization truss problems the constraints were
handled by using exterior penalty functions. The results of the truss optimization model were obtained
by using MATLAB which demonstrated the effectiveness and applicability of these derivative free
methods. It was concluded that the results of Nelder-Mead method were not acceptable due to their far
away convergence even its number of function evaluations were smaller than number of function
evaluations of Multi-Directional Search method and Hooke and Jeeves method. By comparing the
optimal function values obtained by these three methods, the performance of Hooke-Jeeves method
was better than the other two methods.