Contact analysis of a flexible bladed-rotor教材.pdfVIP

European Journal of Mechanics A/Solids 26 (2007) 541–557 Contact analysis of a flexible bladed-rotor N. Lesaffre ∗ , J.-J. Sinou, F. Thouverez Ecole Centrale de Lyon, Laboratoire de Tribologie et Dynamique des Systèmes, UMR CNRS 5513, Equipe Dynamique des Systèmes et des Structures, 36, avenue Guy de Collongue, 69134 Ecully Cedex, France Received 1 December 2005; accepted 30 November 2006 Available online 29 December 2006 Abstract This paper presents a model of fully flexible bladed rotor developed in the rotating frame. An energetic method is used to obtain the matrix equations of the dynamic behaviour of the system. The gyroscopic effects as well as the spin softening effects and the centrifugal stiffening effects, taken into account through a pre-stressed potential, are included in the model. In the rotating frame, the eigenvalues’ imaginary parts of the latter matrix equation give the Campbell diagram of the system and its stability can be analysed through its associated eigenvalues’ real parts. The turbo machine casing is also modelled by an elastic ring in the rotating frame through an energetic method. Thus, in some rotational speed ranges the contact problem between the rotor and the stator can be treated as a static problem since both structures are stationary to each other. Prior to the study of the complete problem of contact between the flexible blades of the rotor and the flexible casing, a simple model of an elastic ring having only one mode shape, excited by rotating loads is developed in the rotating frame too, in order to underline divergence instabilities and mode couplings. Then, the complete problem of frictionless sliding contact between the blades and the casing, without rubbing, is studied. The stable balanced static con