The integrated optimum problem of structures subjected to strong earthquake
s and wind excitations, optimizing the number of actuators, the configurati
on of actuators and the control algorithms simultaneously, is studied. Two
control algorithms, optimal control and acceleration feedback control, are
used as the control algorithms. A multi-level optimization model is propose
d with respect to the solution procedure of the optimum problem. The charac
teristics of the model are analysed, and the formulation of each suboptimiz
ation problem at each level is presented. To solve the multi-level optimiza
tion problem, a multi-level genetic algorithm (MLGA) is proposed. The propo
sed model and MLGA are used to solve two multi-level optimization problems
in which the optimization of the number of actuators, the positions of actu
ators and the control algorithm are considered in different levels. In prob
lem 1, an example structure is excited by strong wind, and in problem 2, an
example structure is subjected to strong earthquake excitation. Copyright
(C) 2001 John Wiley & Sons, Ltd.