AN EVOLUTIONARY STRUCTURAL OPTIMIZATION METHOD FOR SIZING PROBLEMS WITH DISCRETE DESIGN VARIABLES

This paper presents a simple evolutionary method for minimizing the we ight of structures subject to displacement constraints, where sizing d esign variables are discrete. Sensitivity numbers for element size red uction are derived using optimality criteria methods. An optimal desig n can be obtained by gradually reducing elements which have the lowest sensitivity numbers until one of the constrained displacements reache s its given limit. It is shown;that the proposed method can directly d eal with discrete design variables. A simple smoothing technique is em ployed to suppress formation of checker-board patterns. Examples are p rovided to demonstrate the capability of the proposed method for discr ete sizing optimization problems. (C) 1998 Elsevier Science Ltd. All r ights reserved.