Noise Effects on Modal Parameters Extraction of Horizontal Tailplane by Singular Value Decomposition Method Based on Output Only Modal Analysis

Document Type : Research Paper


Vibration and Modal Analysis Research Lab, Faculty of Mechanical Engineering, University of Tabriz, Tabriz, Iran



According to the great importance of safety in aerospace industries, identification of dynamic parameters of related equipment by experimental tests in operating conditions has been in focus. Due to the existence of noise sources in these conditions the probability of fault occurrence may increases. This study investigates the effects of noise in the process of modal parameters identification by Output only Modal Analysis (OMA) method using Singular Value Decomposition (SVD) algorithm. The study case is the horizontal tailplane of the aircraft; therefore, at first, the modal parameters of the tailplane are obtained numerically. Then a cantilever beam is used to perform experimental tests with regard to the high aspect ratio of the modeled tailplane. The modal parameters of the beam are obtained nonparametrically by Experimental Modal Analysis (EMA) and OMA. In order to investigate the effects of noise in a controlled manner, the artificial excitation namely the shaker with the random force is used. Then, the effects of noisy measurements on the specifications of the system in EMA and OMA methods are investigated. The results indicate that: 1. The OMA method has more resistance against the noise for extracting natural frequencies. 2. The results of the Modal Assurance Criterion (MAC) values by EMA method, in the condition of noise existence in output data, are worse than the noise existence in input data. 3. The average of MAC values in general condition of EMA method by noisy input & output data is worse than the OMA method.


[1] Fu Z.F., He J., 2001, Modal Analysis, Elsevier.
[2] Safarabadi M., Mohammadi M., Farajpour A., Goodarzi M., 2015, Effect of surface energy on the vibration analysis of rotating nanobeam, Journal of Solid Mechanics 7(3): 299-311.
[3] Mohammadi M., Farajpour A., Goodarzi M., Mohammadi H., 2013, Temperature effect on vibration analysis of annular graphene sheet embedded on visco-Pasternak foundation, Journal of Solid Mechanics 5(3): 305-323.
[4] Goodarzi M., Mohammadi M., Farajpour A., Khooran M., 2014, Investigation of the effect of pre-stressed on vibration frequency of rectangular nanoplate based on a visco-Pasternak foundation, Journal of Solid Mechanics 6(1): 98-121.
[5] Goodarzi M., Mohammadi M., Khooran M., Saadi F., 2016, Thermo-mechanical vibration analysis of FG circular and annular nanoplate based on the visco-pasternak foundation, Journal of Solid Mechanics 8(4): 788-805.
[6] Arda M., Aydogdu M., 2018, Longitudinal magnetic field effect on torsional vibration of carbon nanotubes, Journal of Computational Applied Mechanics 49(2): 304-313.
[7] Hosseini M., Hadi A., Malekshahi A., Shishesaz M., 2018, A review of size-dependent elasticity for nanostructures, Journal of Computational Applied Mechanics 49(1): 197-211.
[8] Goodarzi M., Bahrami M.N., Tavaf V., 2017, Refined plate theory for free vibration analysis of FG nanoplates using the nonlocal continuum plate model, Journal of Computational Applied Mechanics 48(1): 123-136.
[9] Zargaripoor A., Daneshmehr A., Isaac Hosseini I., Rajabpoor A., 2018, Free vibration analysis of nanoplates made of functionally graded materials based on nonlocal elasticity theory using finite element method, Journal of Computational Applied Mechanics 49(1): 86-101.
[10] Lau J., Debille J., Peeters B., Giclais S., Lubrina P., Boeswald M., Govers Y., 2011, Advanced systems and services for ground vibration testing—application for research test on an Airbus A340-600 Aircraft, 15th International Forum on Aeroelasticity and Structgural Dynamics, Paris, France.
[11] Neu E., Janser F., Khatibi A.A., Orifici A.C., 2015, Operational modal analysis of a cantilever in a wind tunnel using optical fiber bragg grating sensors, Proceedings of the 6th International Operational Modal Analysis Conference, Gijón, Spain.
[12] Neu E., Janser F., Khatibi A.A., Braun C., Orifici A.C., 2016, Operational modal analysis of a wing excited by transonic flow, Aerospace Science and Technology 49: 73-79.
[13] Neu E., Janser F., Khatibi A.A., Orifici A.C., 2017, Fully automated operational modal analysis using multi-stage clustering, Mechanical Systems and Signal Processing 84: 308-323.
[14] Jelicic G., Schwochow J., Govers Y., Sinske J., Buchbach R., Springer J., 2017, Online monitoring of aircraft modal parameters during flight test based on permanent output-only modal analysis, 58th AIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference.
[15] Jia P., Lai S.K., Zhang W., Lim C.W., 2014, Experimental and FEM modal analysis of a deployable-retractable wing, Modern Mechanical Engineering 4(04):183.
[16] Moaveni B., Barbosa A.R., Conte J.P., Hemez F.M., 2014, Uncertainty analysis of system identification results obtained for a seven story building slice tested on the UCSDNEES shake table, Structural Control and Health Monitoring 21(4): 466-483.
[17] Mellinger P., Döhler M., Mevel L., 2016, Variance estimation of modal parameters from output-only and input/output subspace-based system identification, Journal of Sound and Vibration 379: 1-27.
[18] Pintelon R., Schoukens J., 1990, Robust identification of transfer functions in the s-and z-domains, IEEE Transactions on Instrumentation and Measurement 39(4): 565-573.
[19] Gu G., Misra P.R.A.D.E.E.P., 1992, Identification of linear time-invariant systems from frequency-response data corrupted by bounded noise, IEE Proceedings D-Control Theory and Applications 139(2): 135-140.
[20] Bai E.W., Raman S., 1993, A linear interpolatory algorithm for robust system identification with corrupted measurement data, IEEE Transactions on Automatic Control 38(8): 1236-1241.
[21] Pintelon R., Guillaume P., Schoukens J., 1996, Measurement of noise (cross-) power spectra for frequency-domain system identification purposes: large-sample results, IEEE Transactions on Instrumentation and Measurement 45(1):12-21.
[22] Schoukens J., Pintelon R., 2006, Estimation of nonparametric noise models, Instrumentation and Measurement Technology Conference.
[23] Schoukens J., Pintelon R., Rolain Y., 2004, Box–Jenkins alike identification using nonparametric noise models, Automatica 40(12): 2083-2089.
[24] Schoukens J., Rolain Y., Pintelon R., 2010, On the use of parametric and non-parametric noise-models in time-and frequency domain system identification, Decision and Control (CDC).
[25] Juang J.N., Pappa R.S., 1986, Effects of noise on modal parameters identified by the eigensystem realization algorithm, Journal of Guidance, Control, and Dynamics 9(3): 294-303.
[26] Li P., Hu S.L.J., Li H.J., 2011, Noise issues of modal identification using eigensystem realization algorithm, Procedia Engineering 14:1681-1689.
[27] Dorvash S., Pakzad S.N., 2012, Effects of measurement noise on modal parameter identification, Smart Materials and Structures 21(6): 065008.
[28] Brincker R., Zhang L., Andersen P., 2000, Modal identiļ¬cation from ambient responses using frequency domain decomposition, 18th International Modal Analysis Conference (IMAC), San Antonio, Texas.
[29] Brincker R., Zhang L., Andersen P., 2001, Modal identification of output-only systems using frequency domain decomposition, Smart Materials and Structures 10(3): 441.
[30] Ayari F., Bayraktar E., 2011, Parametric study to optimize aluminum shell structure under various conditions, Experimental and Applied Mechanics, 6: 439-450.
[31] Ewins D.J., 1984, Modal Testing: Theory and Practice, Letchworth, Research Studies Press.
[32] Rahman A.G.A., Ong Z.C., Ismail Z., 2011, Enhancement of coherence functions using time signals in modal analysis, Measurement 44(10): 2112-2123.
[33] Richardson M.H., Formenti D.L., 1982, Parameter estimation from frequency response measurements using rational fraction polynomials, Proceedings of the 1st International Modal Analysis Conference, Union College Schenectady.
[34] Brincker R., Ventura C., Andersen P., 2001, Damping estimation by frequency domain decomposition, 19th International Modal Analysis Conference.
[35] Haddadpour H., Firouz-Abadi R.D., 2006, Evaluation of quasi-steady aerodynamic modeling for flutter prediction of aircraft wings in incompressible flow, Thin-Walled Structures 44(9): 931-936.
[36] Moosavi M.R., Oskouei A.N., Khelil A., 2005, Flutter of subsonic wing, Thin-Walled Structures 43(4): 617-627.
[37] Allemang R.J., Brown D.L., 1982, A correlation coefficient for modal vector analysis, Proceedings of the 1st International Modal Analysis Conference, SEM Orlando.