3D NONLINEAR FLUTTER ANALYSIS IN FREQUENCY-DOMAIN OF LONG-SPAN BRIDGES

Based on the PK?F method,an approach of three dimensional nonlinear flutter analysis in frequency domain is described herein,in which the effects of both structural and aeroelastic force nonlinearities have been taken into consideration.Structural behaviors in pre and post flutter status and flutter critical condition can be predicted.Some complicated factors such as various section shapes in one bridge,complex structures can be conveniently considered.Finally,by taking Jiangyin suspension bridge over the Yangze River with a streamlined deck of 1 385 m and Jingsha cable stayed bridge with a bluff deck of 500 m as examples, nonlinear flutter analysis is performed.Furthermore,flutter mechanism of those different sections and the role of nonlinearities in flutter analysis is clarified.