Stability of Elastically Restrained Valve-Pipe System With Crack

Abstract

The dynamic stability and natural frequency of elastically restrained pipe conveying fluid with the attached mass and crack are investigated in this paper. The pipe system with a crack is modeled by using extended Hamilton's principle with consideration of bending energy. The crack on the pipe system is represented by a local flexibility matrix and two undamaged beam segments are connected. The crack is assumed to be in the first mode of fracture and to be always opened during the vibrations. From the governing equations, the influence of attached mass, its position and crack on the dynamic stability of elastically restrained pipe system is presented. Also, the critical flow velocity for the flutter and divergence due to the variation in the position and stiffness of supported spring is studied. Finally, the critical flow velocities and stability maps of the cracked pipe conveying fluid with the attached mass are obtained by the changing parameters.