Identification of 18 flutter derivatives of bridge decks

Current theories for analyzing the responses of bridges to wind are based on their flutter derivatives, which can be extracted from the wind-tunnel tests. Based on the existing identification theory by using the experimental system of 2-DOF sectional models, the general least-squares theory for identifying 18 flutter derivatives of bridge deck sections is developed in this paper. All 18 flutter derivatives of three typical kinds of bridge decks, i.e., a plate section, a streamlined box girder section and a π-shaped section are obtained from the free vibration time histories of motions by employing the general least-squares theory. The flutter derivatives from testing are compared with the results from CFD approach. Furthermore, the estimated values based on the pseudo-steady formulation are also verified with the experimental results. Experimental determination and study of all 18 derivatives will significantly advance the understanding of the physical mechanism of bridges to wind loading.