Mode shape description of an aero-engine casing structure using Zernike moment descriptors  

作　　者：LIU Ying-chao ZANG Chao-ping 

机构地区：[1]College of Energy and Power Engineering,Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China

出　　处：《航空动力学报》2011年第4期760-770,共11页Journal of Aerospace Power

基　　金：Supported by Research Fund for the Doctoral Program of Higher Education of China(20093218110008);The SRF for ROCS,SPM(No.R0861-21);Jiangsu Research Foundation of Talented Scholars in Six Fields(No.P0951-021);The Nanjing University of Aeronautics and Astronautics Postgraduate Innovation Fund

摘　　要：Vibration mode shape description of an aero-engine casing structure using Zernike moment descriptor(ZMD) was introduced in this paper.The mode shapes of the aero-engine casing structure can be decomposed as a linear combination of a series of Zernike polynomials,with the feature of each Zernike polynomial reflecting a part of characteristic of mode shapes,based on Zernike moment transformation.Meanwhile,the reconstruction of mode shapes with ZMD was explored and its ability to filtering the noise contaminated in the mode shapes was studied.Simulation of the aero-engine casing structure indicated the advantage of this method to depict the mode shapes of a symmetric structure.Results demonstrate that the Zernike moment description of the mode shapes can effectively describe the double modes in the symmetric structure and also has the ability to remove or significantly reduce the influence of noise in the mode shapes.Such feature shows great practical value for further research on the correlation,model updating and model validation of the symmetric structure's finite element model.Vibration mode shape description of an aero-engine casing structure using Zernike moment descriptor（ZMD） was introduced in this paper.The mode shapes of the aero-engine casing structure can be decomposed as a linear combination of a series of Zernike polynomials,with the feature of each Zernike polynomial reflecting a part of characteristic of mode shapes,based on Zernike moment transformation.Meanwhile,the reconstruction of mode shapes with ZMD was explored and its ability to filtering the noise contaminated in the mode shapes was studied.Simulation of the aero-engine casing structure indicated the advantage of this method to depict the mode shapes of a symmetric structure.Results demonstrate that the Zernike moment description of the mode shapes can effectively describe the double modes in the symmetric structure and also has the ability to remove or significantly reduce the influence of noise in the mode shapes.Such feature shows great practical value for further research on the correlation,model updating and model validation of the symmetric structure＇s finite element model.

关 键 词：ZERNIKE mode shape modal assurance criterion(MAC) RECONSTRUCTION noise filtering 

分 类 号：O174.43[理学—数学] V231.92[理学—基础数学]