Reduction and Modification for Aero Engine Rotor Model Considering Contact Stiffness

Abstract: Aiming at the difficulty of both accuracy and computational efficiency in aero engine rotor model, a method of dimensionality reduction and modification of aero engine rotor model considering contact stiffness is proposed. First, a three-dimensional finite element model of the aero-engine rotor is established, using thin-layer elements to represent the end-tooth contact interface between rotor discs. Second, based on the Craig-Bampton fixed-interface modal synthesis method, a reduced model of the rotor is obtained, retaining the main nodes at the bearing and the end-tooth contact interface positions. Finally, the contact stiffness in the reduced rotor model is modified based on the sensitivity method and rotor modal testing. The maximum frequency error of the first three orders of bending mode frequencies calculated by the modified model is reduced from 12.84% to 0.11%, and the calculated modal shapes are consistent with the experimental results. Moreover, the average time of five iterations of correction calculation is 0.8 seconds on the platform of Matlab software, which verifies the accuracy and efficiency of the method. The calculation results show that the dimensionality reduction and modification method considering contact stiffness can not only satisfy the correction accuracy, but also significantly improve the model correction efficiency of aero engine rotor.

Keywords: Aero Engine Rotor, Model Modification, Thin Layer Element, Dimensionality Reduction, Contact Stiffness

DOI: 10.54941/ahfe1005199

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