A PSEUDO-DISCRETE ROUNDING METHOD FOR STRUCTURAL OPTIMIZATION

A new heuristic method aimed at efficiently solving the mixed-discrete nonlinear programming (MDNLP) problem in structural optimization, and denoted selective dynamic rounding, is presented. The method is based on the sequential rounding of a continuous solution and is in its cur rent form used for the optimal discrete sizing design of truss structu res. A simple criterion based on discrete variable proximity is propos ed for selecting the sequence in which variables are to be rounded, an d allowance is made for both upward and downward rounding. While effic ient in terms of the required number of function evaluations, the meth od is also effective in obtaining a low discrete approximation to the global optimum. Numerical results are presented to illustrate the effe ctiveness and efficiency of the method.