Abstract:Based on a tentative design of suspension bridges with a PC slab stiffening girder in Guizhou Province, the sectional model wind test has been carried out to identify flutter derivatives of the stiffening girder, by using the Forced Vibration Technique at the wind angle of attack -3°,0°and 3°. With a second development of the software ANSYS, full-mode flutter analysis of the bridge in frequency domain is implemented, considering the influence of wind angle of attack under construction stage and in-service state. It is found that the presented handrail on the stiffening girder apparently enervates bridge flutter instability at zero angle of attack; for both the construction stage and the in-service state, the flutter onset wind speeds of the bridge are significantly decreasing under negative wind angle of attack; while very high flutter onset wind speeds occur at positive angle of attack in both construction stage and in-service sate. Because of the very sensitive flutter instability of such kind of bridge to wind angle of attack, studies on the suitable selection of the handrail shape as well as the wind environment at bridge site should be highlighted.