In this study, in-flight modal identification analyses are made based on vibration data collected during a flight test of an aircraft, by using two different output-only identification techniques: frequency domain decomposition and data-driven stochastic subspace identification. The purpose of this study was to evaluate and compare the efficacy of the two methods in modal parameter estimation and to validate their capability in dealing with some challenging tasks such as time tracking of modal parameters and estimating modal damping ratios. In addition, the effects of different environmental conditions and maneuvers are investigated by separating the flight-test data, such as static engine start, taxi, takeoff, cruise, roll, climb, descend, and yaw maneuvers. It is demonstrated that the selection of operational conditions and maneuvers plays a crucial role in identifying the modal parameters of the aircraft.
AdamsDE (2007) Health Monitoring of Structural Materials and Components: Methods with Applications. West Sussex, UK: John Wiley & Sons.
2.
AllemangRJ (2003) The modal assurance criterion -twenty years of use and abuse. Sound and Vibration37(8): 14–21.
3.
AuS-K (2014) Uncertainty law in ambient modal identification-part II: implication and field verification. Mechanical Systems and Signal Processing48(1–2): 34–48.
BajrićABrinckerRThönsS (2015) Evaluation of damping estimates in the presence of closely spaced modes using operational modal analysis techniques. In: 6th international operational modal analysis conference IOMAC, Gijón, Spain, 12–14 May 2015. Gijón, Spain: International Operational Modal Analysis Conference (IOMAC).
6.
Bautista-De CastroASanchez-AparicioLJRamosLF, et al. (2018) Integrating geomatic approaches, operational modal analysis, advanced numerical and updating methods to evaluate the current safety conditions of the historical Bôco bridge. Construction and Building Materials158: 961–984.
7.
BollerC (2009) Structural health monitoring: an introduction and definitions. In: Encyclopedia of Structural Health Monitoring. Chichester: John Wiley & Sons.
8.
BrinckerRAndersenP (2006) Understanding stochastic subspace identification. In: 24th international modal analysis conference, St. Louis, MO, 30 January–2 February. Bethel, CT: Society for Experimental Mechanics Inc.
9.
BrinckerRAndersenPJacobsenN (2007) Automated frequency domain decomposition for operational modal analysis. In: Proceedings of the 25th international modal analysis conference. Orlando, FL, 19–22 February 2007, pp. 1–7. Bethel, CT: Society for Experimental Mechanics Inc.
10.
BrinckerRVenturaCE (2015) Introduction to Operational Modal Analysis. West Sussex, UK: John Wiley & Sons.
11.
BrinckerRVenturaCEAndersenP (2001a) Damping estimation by frequency domain decomposition. In: 19th international modal analysis conference, Kissimmee, FL, 05–08 February 2001, pp. 698–703. Bethel, CT: Society for Experimental Mechanics Inc.
12.
BrinckerRZhangLAndersenP (2000) Modal identification from ambient responses using frequency domain decomposition. In: Proceedings of the 18th international modal analysis conference. San Antonio, TX, 07–10 February 2000, pp. 625–630. Bethel, CT: Society for Experimental Mechanics Inc.
13.
BrinckerRZhangLAndersenP (2001b) Modal identification of output-only systems using frequency domain decomposition. Smart Materials and Structures10(3): 441–445.
14.
BrownjohnJMMagalhaesFCaetanoE, et al. (2010) Ambient vibration re-testing and operational modal analysis of the Humber Bridge. Engineering Structures32: 2003–2018.
15.
ChauhanSTcherniakDBasurkoJ, et al. (2011) Operational modal analysis of operating wind turbines: application to measured data. In: Rotating Machinery, Structural Health Monitoring, Shock and Vibration. New York: Springer, Vol. 5, 65–81.
16.
ChenG-WOmenzetterPBeskhyrounS (2017) Operational modal analysis of an eleven-span concrete bridge subjected to weak ambient excitations. Engineering Structures151: 839–860.
17.
CoppotelliGContiEVan TongerenH (2018) Modal parameters estimate of AH-64D Apache helicopter from flight data and correlation with numerical model. AIAA/ASCE/AHS/ASC structures, structural dynamics, and materials conference, Kissimmee, FL, 08–12 January 2001. Reston, VA: American Institute of Aeronautics and Astronautics.
18.
CoppotelliGGrappasonniC, and TozziD (2013) Operational modal analysis from flight test data. In: 5th International operational modal analysis conference, Guimaraes, Portugal, 13–15 May 2013. Gijón, Spain: International Operational Modal Analysis Conference (IOMAC).
19.
DevriendtCDe TroyerTDe SitterG, et al. (2012) Transmissibilty-based operational modal analysis for flight flutter testing using exogenous inputs. Shock and Vibration19(5): 1071–1083.
20.
DevriendtCMagalhaesFWeijtjensW, et al. (2014) Structural health monitoring of offshore wind turbines using automated operational modal analysis. Structural Health Monitoring: An International Journal13(6): 644–659.
21.
DongXLianJWangH, et al. (2018) Structural vibration monitoring and operational modal analysis of offshore wind turbine structure. Ocean Engineering150: 280–297.
22.
FolladorRDCSouzaCEdMartoAG, et al. (2016) Comparison of in-flight measured and computed aeroelastic damping: modal identification procedures and modeling approaches. Journal of Aerospace Technology and Management8: 163–177.
23.
GentileCSaisiACabboiA (2015) Structural identification of a masonry tower based on operational modal analysis. International Journal of Architectural Heritage9(2): 98–110.
24.
GoversYSinskeJSchwochowJ, et al. (2017) Efficient ground vibration testing of aircraft based on output-only modal analysis during taxi. In: 58th AIAA/ASCE/AHS/ASC structures, structural dynamics, and materials conference, Grapevine, TX, 9–13 January 2017. Reston, VA: American Institute of Aeronautics and Astronautics.
25.
IovnovichMNahomTPresmanM, et al. (2018) Assessment of advanced flutter flight-test techniques and flutter boundary prediction methods. Journal of Aircraft55: 1–13.
26.
JamesGKaoukMCaoT, et al. (2012) Operational analysis in the launch environment. In: Topics in Modal Analysis I. New York: Springer, Vol. 5, pp. 249–264.
27.
JelicicGSchwochowJGoversY, et al. (2017) Online monitoring of aircraft modal parameters during flight test based on permanent output-only modal analysis. In: 58th AIAA/ASCE/AHS/ASC structures, structural dynamics, and materials conference, Grapevine, TX, 9–13 January 2017. Reston, VA: American Institute of Aeronautics and Astronautics.
28.
KandilKSASaudiGNEltalyBA-A, et al. (2016) Seismic response of a full-scale wind turbine tower using experimental and numerical modal analysis. International Journal of Advanced Structural Engineering8(4): 337–349.
29.
KatafygiotisLSYuenK-V (2001) Bayesian spectral density approach for modal updating using ambient data. Earthquake Engineering & Structural Dynamics30(8): 1103–1123.
30.
KvâleKAØisethORønnquistA (2017) Operational modal analysis of an end-supported pontoon bridge. Engineering Structures148: 410–423.
31.
LalanneC (2014) Random Vibration. Hoboken, NJ: John Wiley & Sons, Ltd, 1–77.
32.
LauJPeetersBDebilleJ, et al. (2011) Ground vibration testing master class: modern testing and analysis concepts applied to an F-16 aircraft. In:Advanced Aerospace Applications. New York: Springer, Vol. 1, 221–228.
33.
LyngdohGARahmanMAMishraSK (2019), Bayesian updating of structural model with a conditionally heteroscedastic error distribution. Journal of Engineering Mechanics145(12): 04019091.
34.
MarrongelliGMagalhãesFCunhaÁ (2017) Automated operational modal analysis of an arch bridge considering the influence of the parametric methods inputs. Procedia Engineering199: 2172–2177.
35.
NeuEJanserFKhatibiAA, et al. (2016) Operational modal analysis of a wing excited by transonic flow. Aerospace Science and Technology49: 73–79.
36.
PeetersBDe RoeckG (1999) Reference-based stochastic subspace identification for output-only modal analysis. Mechanical Systems and Signal Processing13(6): 855–878.
37.
PeetersBDe RoeckG (2001) Stochastic system identification for operational modal analysis: a review. Journal of Dynamic Systems, Measurement, and Control123(4): 659–667.
38.
PeetersBHendricxWDebilleJ, et al. (2009) Modern solutions for ground vibration testing of large aircraft. Sound and Vibration43(1): 8.
39.
RainieriCFabbrocinoG (2014) Operational Modal Analysis of Civil Engineering Structures. New York: Springer.
40.
RequesonORTcherniakDLarsenGC (2015) Comparative study of OMA applied to experimental and simulated data from an operating Vestas V27 wind turbine. In: 6th international operational modal analysis conference, Gijón, Spain, 12–14 May 2015. Gijón, Spain: International Operational Modal Analysis Conference.
41.
SchulzePCDanowskyBPYangP, et al. (2017) Real time modal identification of a flexible unmanned aerial vehicle. In: AIAA atmospheric flight mechanics conference, Grapevine, TX, 9–13 January 2017, pp. 1–13. Reston, VA: American Institute of Aeronautics and Astronautics.
42.
TamuraYYoshidaAZhangL, et al. (2005) Examples of modal identification of structures in Japan by FDD and MRD techniques. In: 1st international operational modal analysis conference. Copenhagen, Denmark.
43.
TarinejadRPourgholiM (2016) Modal identification of arch dams using balanced stochastic subspace identification. Journal of Vibration and Control24: 2030–2044.
44.
TorresWAlmazánJLSandovalC, et al. (2017) Operational modal analysis and FE model updating of the Metropolitan Cathedral of Santiago, Chile. Engineering Structures143: 169–188 .
45.
UbertiniFGentileCMaterazziAL (2013) Automated modal identification in operational conditions and its application to bridges. Engineering Structures46: 264–278.
46.
Van OverscheePDe MoorB (1996) Subspace Identification for Linear Systems: Theory, Implementation, Applications. Norwell, MA: Kluwer Academic Publishers.
47.
ZhangYZhangZXuX, et al. (2005) Modal parameter identification using response data only. Journal of Sound and Vibration282(1–2): 367–380.
