Reconstruction of impulse response function based on correlation function under ambient excitation

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Journal of Vibration and Shock ›› 2020, Vol. 39 ›› Issue (10) : 220-227.

ZHANG Jichun,SONG Hanwen

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Abstract

The correlation functions (CFs) are treated as substitution of the impulse response functions (IRFs) for modal parameters identification under white noise excitation.However, a clear explanation of CFs is still absent.As is known, all the dynamic characteristics can be described with IRFs, however, the modal participation factors, or the mass information, cannot be identified using CFs, which is the main defect of operational modal analysis (OMA) as well.Under the complex mode assumption, the natural excitation technique (NExT) was reviewed.Then, the equivalence between CFs of displacements subjected to white noise excitation and the free responses under certain initial condition was derived.In addition, the initial condition for the free responses was provided.Furthermore, a mass distribution identification method was proposed and IRFs were reconstructed.The influence of time length and excitation bandwidth on the CF errors was discussed.Finally, a numerical simulation example and an experiment was designed to illustrate the effectiveness of the proposed method.

Key words

ambient excitation / correlation function (CF) / free response / impulse response function (IRF) / mass distribution identification

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ZHANG Jichun,SONG Hanwen. Reconstruction of impulse response function based on correlation function under ambient excitation[J]. Journal of Vibration and Shock, 2020, 39(10): 220-227

References

[1] Brincker R, Ventura C. Introduction to operational modal analysis[M]. New York: John Wiley and Sons, 2015.

[2] Brincker R. Some elements of operational modal analysis[J]. Shock and Vibration, 2014, 2014(4):1-11.

[3] Parloo E, Cauberghe B, Benedettini F, et al. Sensitivity-based operational mode shape normalisation: application to a bridge[J]. Mechanical Systems and Signal Processing, 2005, 19(1): 43-55.

[4] Jaishi B, Kim H, Kim M K, et al. Finite element model updating of concrete-filled steel tubular arch bridge under operational condition using modal flexibility[J]. Mechanical Systems and Signal Processing, 2007, 21(6): 2406-2426.

[5] Aenlle M L, Brincker R. Modal scaling in operational modal analysis using a finite element model[J]. International Journal of Mechanical Sciences, 2013, 76: 86-101.

[6] Papoulis A, Pillai S U. Probability, random variables, and stochastic processes[M]. Fourth edition. New York: Mc Graw Hill, 2002.

[7] James G H. Extraction of modal parameters from an operating HAWT using the Natural Excitation Technique (NExT)[A]. Proceedings of the 13th Energy-Sources Technology Conference and Exhibition (ETCE) on Wind Energy[C]. New Orleans, Louisiana, USA: 1994: 23-26.

[8] James G H, Carne T G, Lauffer J P. The natural excitation technique (NExT) for modal parameter extraction from operating structures[J]. Modal Analysis - the International Journal of Analytical and Experimental Modal Analysis. 1995, 4(10): 260-277.

[9] James G H, Carne T G, Edmunds R S. Stars missile- modal analysis of first-flight data using the natural excitation technique, NExT[J]. Proceedings of SPIE - The International Society for Optical Engineering, 1993, 154(4):749–757.

[10] James G. Development of operational modal analysis techniques for launch data[J]. Advances in the Astronautical Sciences, 2013, 147.

[11] 于亮亮, 宋汉文. 激励中含有谐波成分时的工况模态参数辨识[J]. 振动工程学报, 2018, 31(1): 74-81.

Yu L L, Song H W. Operational modal analysis in the presence of harmonic excitation[J]. Journal of Vibration Engineering, 2018, 31(1): 74-81.

[12] 于亮亮, 宋汉文. 环境激励下脉冲响应函数与相关函数的关系[J]. 噪声与振动控制, 2017, 37(3): 14-19.

Yu L L, Song H W. Discussion on the relation between correlation functions and impulse response functions under ambient excitation[J]. Noise and Vibration Control, 2017, 37(3): 14-19.

[13] 秦飞，宋汉文，王文亮. 基于现代谱估计理论的工况模态分析[J]. 振动与冲击, 2002(4): 74-79.