Dynamic stiffness analysis of follower moments

Abstract

The dynamic stiffness method can predict an infinite number of natural modes of a conservative structure by means of a finite number of coordinates. The methos is extended to a nonconservative system characterized by follower moments to investigate the dynamic lateral buckling and flutter in this paper. Straight beam members with doubly symmetrical cross-sections are of interest, and skeletal frames are taken as examples. Flexural and torsional modes are coupled. The fact that the applied moment softens the flexural modes, but hardens the torsional modes, makes the characteristic diagram much more complicated than that of follower forces. Isola loops are possible.