Identification of stiffness and periodic excitation forces of a transverse switching crack in a Laval rotor
Article first published online: 9 AUG 2012
© 2012 Wiley Publishing Ltd.
Fatigue & Fracture of Engineering Materials & Structures
Volume 36, Issue 3, pages 254–269, March 2013
How to Cite
SHRAVANKUMAR, C. and TIWARI, R. (2013), Identification of stiffness and periodic excitation forces of a transverse switching crack in a Laval rotor. Fatigue & Fracture of Engineering Materials & Structures, 36: 254–269. doi: 10.1111/j.1460-2695.2012.01718.x
- Issue published online: 14 FEB 2013
- Article first published online: 9 AUG 2012
- Received in final form 8 June 2012
- crack excitation force;
- crack stiffness;
- switching crack;
- system identification;
- unbalance and damping
This work involves model-based identification of rotor crack. A Laval rotor with a transverse surface crack and disc unbalance is studied. Viscous damping, disc eccentricity and additive stiffness due to crack are the parameters considered for identification. The linear system equations of motion together with the switching crack excitation function are used for developing the identification algorithm. Furthermore, the algorithm is extended for a novel attempt of estimating the coefficients of switching crack excitation function, which constitute the crack excitation force. This estimation could be used to provide valuable information on the actual opening/closing profile of the switching crack. The proposed algorithms are illustrated through numerical examples. They are tested against measurement noise and found to be reasonably robust.