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• The unbalance responses of the rotor system are used to update the FE model. • Gaussian process (GP) model is used to describe the mapping relationship between the selected parameters and fusion features. • An adaptive sampling strategy is developed to reduce the computation cost of repeated finite element (FE) calculation. • Multi-channel data fusion is adopted to construct the objective function of the model updating. • The unbalance responses at different rotating speeds of the updated model are both close to the measured responses. • The modal frequencies of the updated FE model at different rotating speeds are both close to the measured model. For predicting the dynamic responses of rotor system with high accuracy, an adaptive Gaussian process model-based model updating method for rotor system using the unbalance responses is proposed. To utilize the data from multiple sensors, multi-channel data fusion is adopted to construct the objective function of the model updating. The fusion feature is the mean of the cumulative distribution function of the response errors of each channel. The Gaussian process model is used to describe the mapping relationship between the selected parameters and fusion features. An adaptive sampling strategy is developed to reduce the computation cost of repeated finite element calculation. Based on Sobol sequence sampling, new sampling parameters are added near the sample parameter with a larger error in the predicted value. The performance of the proposed method is validated by a gas-generator rotor and a dual-disks rotor. Results show that the unbalance responses of the updated model show good agreement with the exact responses and measured responses. The maximum error of the support parameters for the gas-generator rotor is 3.56%. For the dual-disks rotor, the discrepancies of the first three modal frequencies between the updated model and the measured model are below 1%, 2.5% and 5%. The proposed method is effective for model updating of the rotor system. [ABSTRACT FROM AUTHOR]

This paper concerns a general method to predict unbalance responses for a geared rotor system, which contains n shafts and at least n −1 spur and/or helical gear meshes. Finite element models of spur gear pairs and helical gear pairs are developed with arbitrary orientation angles, respectively. Then, a general method with a strict mathematical proof is proposed to calculate maximum axis radii of the unbalance response orbit for a geared rotor system. The proposed method is validated through three applications, i.e, a spur geared two-shaft rotor system, a spur geared multi-shaft rotor system and a helical geared multi-shaft rotor system. A classical modal synthesis is also employed as a comparison. Results show that proposed analytical solutions are consistent with the numerical results and have advantages over the modal synthesis. In addition, plenty of computer processing time can be saved with the proposed method. The method reported here may be of interest to engineers and educators attempting to handle the unbalance response analysis effectively and easily. [ABSTRACT FROM AUTHOR]

Mathematical models of structure or machineries are always different from the existing physical system, because the approach of numerical predictions to the behavior of a physical system is limited by the assumptions used in the development of the mathematical model. Model updating is, therefore necessary so that updated model should replicate the physical system. This work focuses on the model updating of rotor systems at various speeds as well as at different modes of vibration. Support bearing characteristics severely influence the dynamics of rotor systems like turbines, compressors, pumps, electrical machines, machine tool spindles etc. Therefore bearing parameters (stiffness and damping) are considered to be updating parameters. A finite element model of rotor systems is developed using Timoshenko beam element. Unbalance response in time domain and frequency response function have been calculated by numerical techniques, and compared with the experimental data to update the FE-model of rotor systems. An algorithm, based on unbalance response in time domain is proposed for updating the rotor systems at different running speeds of rotor. An attempt has been made to define Unbalance response assurance criterion (URAC) to check the degree of correlation between updated FE model and physical model. [ABSTRACT FROM AUTHOR]