An identification method of distributed imbalance without trial weights for high speed rotors

To avoid the vibration induced by distributed imbalance, an identification method without trial weights of distributed imbalance for high speed rotors, which only need to collect vibration data below the first critical speed, is presented. First, the relationship between the dynamics transfer function and the influence coefficients was identified based on the dynamics analysis and the extended influence coefficients principle. Second, the mass eccentricity curve of distributed unbalance was described by the nodes in finite element model, and then, a formula to solve the distributed unbalance imposing on each finite element model node was derived from the full rank of dynamics transfer matrix, which was obtained by increasing the speed. Finally, the experiment analysis was performed on a flexible rotor test rig, and the results demonstrated that the magnitude of the vibration during the first order critical speed was reduced significantly after adding the correcting weights, which implied that the distributed unbalance could be identified accurately by the proposed method.