ALTERNATIVE FORMULATIONS OF STRUCTURAL OPTIMIZATION

Several alternative, but equivalent, formulations of structural optimi zation problems are critically reviewed and compared. The various form ulations differ in the independent variables chosen, the analysis equa tions employed, and the form of the resulting constraints. With regard to the method of analysis used, the displacement method, force method and mixed method of analysis are considered. The problem formulations discussed include (i) those in the Design Variable Space (DVS), (ii) Simultaneous Analysis and Design (SAND), and (iii) Optimality Criteria (OC). Some simplified formulations, approximate approaches and dual m ethods are also reviewed. Moreover, typical characteristics, advantage s and drawbacks of various formulations are discussed and their effect on the solution process pointed out.