Abstract：Based on the characteristic analysis of the system mode, it has been noted that the complex modal parameters of the system could be computed from a characteristic analysis when the reduced wind velocity is known. On the contrary, the corresponding flutter derivatives of bridge decks can be determined in a unique manner on condition that the complex modal parameters of the system at one reduced wind velocity (reduced frequency) are obtained. Based on the idea, a new method for identifying the flutter derivatives of bridge decks from the complex modal parameters of the system is proposed and it is theoretically exact and can overcome the main shortcoming of the existing method. The reliability and applicability of the proposed method to extract the flutter derivatives from coupled free vibration are proved with numerical examples and it could work even then the flutter occurred.
2012, Vol. 31 
