The problem of complex shape tracking in a Campbell Diagram or how to overcome crossing/veering phenomena
Abstract
The correlation criterion proposed in this article and called NC2O (Normalized Cross Complex Orthogonality) ensures bi-orthogonality properties between rotor mode shapes calculated at different speeds of rotation. This criterion is proofed on an industrial laminated rotor composed of disks and two fluid film bearings, whose stiffness and damping characteristics depend on the speed of rotation. The industrial finite element model shows that the NC2O criterion provides a more efficient mode pairing of rotor shapes than those obtained by using the classical correlation criteria. Moreover this criterion maker easier the Campbell diagram plotting of strongly _ -dependent structures