Chaotic response of cracked rotor supported on squeeze film damper and the routes to chaos

In this paper, the chaotic response of a rotor system with crack supported on the squeeze film damper (SFD) is studied. Based on the short bearing approximation and π-film assumption, the film force is expressed as a function of speed and displacement of the bearing in the X and Y directions. The result shows that the film force can suppress the non-synchronous response effectively if an SFD is designed well. The increase of the bearing parameter can suppress chaos. When the bearing parameter is small, a certain range of the rotating speed and crack depth can lead to chaos. The main route to chaos is intermittence chaos. There also exists the route of a quasi-period to chaos. In most cases, periodic-3 movement means that there is or will be a chaotic response.