The research was supported by the National Natural Science Foundation of China(Grant No.50708012);co-supported by the New Faculty Research Fund for the Doctoral Program of Higher Education by the Ministry of Education of China(No.20070141073).
The causes of the nonlinearity of self-excited aerodynamic force of bridge are interpreted from such two aspects as amplitude and wind velocity.The concept of"generalized flutter derivative"is proposed,and its physica...