A model-based diagnosis method of unbalance faults for dual-spool system

Amodel for analyzing unbalance faults in dual-spool system was discussed.The dual-spool model was built using substructure transfer matrix method.Linear superposition theory was used to calculate the response on the support points when the inner and outer rotors have the unbalance faults at the same time.The method of little rotating speed difference for measuring unbalance vibration response was presented.The nonlinear optimization model for identifying the dual-spool unbalance faults was constructed,and the sequence quadratic programming(SQP) was employed to solve them.The sensibility relationship between the unbalance response from the accessible points and dual rotors speeds,or between the unbalance response and unbalance quantity,were given.The possibility of diagnosis for dual rotors unbalance faults was also discussed.The proposed methods are demonstrated using the numerical simulations and experiments.The results show that the method can successfully identify the magnitude and phase of unbalance for dual-spool using the information of speed and a few points' response data with noise.