Efficiency improvement of simulated annealing in optimal structural designs

Although simulated annealing (SA) is one of the easiest optimization algorithms available, the huge number of function evaluations deters its use in structural optimizations. In order to apply SA in structural optimization efficiently the number of finite element analyses (function evaluations) has to be reduced as much as possible. Two methods are proposed in this paper. One is to estimate the feasible region using linearized constraints and the SA searches proceed in the estimated feasible region. The other one makes SA search start with an area containing higher design variable values. The search area is then gradually moved toward the optimum point in the following temperatures. Using these approaches, it is hopeful that the number of finite element analyses in the infeasible region can be greatly reduced. The efficiency of SA is thus increased. Three examples show positive results by these methods. (C) 2002 Civil-Comp and Elsevier Science Ltd. All rights reserved.