大跨度桥梁的三维非线性颤振领域分析

在PK－F法的基础上，考虑结构以及动力随风速的非线性变换因素，提出了大跨度桥梁的三维非线性颤振频域分析方法，该方法能预测出结构在颤振前后整个过程的振动特性以及颤振监界状态，并且可以对结构变截面、复杂结构等情况进行分析，最后，对江阴长江大桥和荆沙长江大桥进行了颤振分析，揭示了非线性因素对桥梁结构颤振特性的影响以及不同断面桥梁结构颤振形态的内在本质和统一性。

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.