Abstract
We applied a free-vibration-based identification method of unsteady aerodynamic forces of bridge deck based on finite state approximate formulation to modal information data obtained by wind tunnel experiments on a thin box girder. This paper also discussed two kinds of the objective functions and their weight factors in the identification procedure as an optimization problem in detail. The results show that modal information and flutter derivatives can be estimated accurately, even though the experimental data contain relatively large error. It is also found that the application of the maximum-likelihood method based on the residual on modal information is effective in determining the weight factors of objective functions.
