Abstract
Wind turbine blades and other structures are often subjected to dynamic loading that may not be predicted or measurable at critical locations of interest. Therefore, a non-contacting measurement technique that can provide information throughout an entire structure with the absence of instrumented sensors is desirable. Such an approach is particularly beneficial and relevant to operating rotor or wind turbine blades. In this paper, a three-bladed wind turbine placed in a semi-built-in boundary condition was subjected to a variety of different loadings. The turbine was excited using a sinusoidal excitation, a pluck test, arbitrary impacts on three blades, and random force excitations with a mechanical shaker. The response of the structure to these excitations at optical targets mounted to the blades was measured using three-dimensional point tracking. The limited set of measured displacement at the optical targets was expanded using a modal expansion algorithm. The expanded displacement was used in conjunction with a finite element model of the turbine to extract dynamic strain throughout the entire structure. The results from the technique were compared to instrumented strain gages and are shown be in close agreement. The predicted strain using the proposed approach is not limited to the locations of the optical targets or where the cameras have line of sight. This new technique may enable a new structural health-monitoring approach that has the ability to interrogate an entire structure, inside and outer surface.
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Abbreviations
- {Xn}:
-
Full-space displacement vector
- {Xa}:
-
Reduced-space displacement vector
- [Ma]:
-
Reduced mass matrix
- [Mn]:
-
Full-space mass matrix
- [Ka]:
-
Reduced stiffness matrix
- [Kn]:
-
Full-space stiffness matrix
- [Ua]:
-
Reduced mode shape matrix
- [Ua]g :
-
Generalized inverse of reduced shape matrix
- [Un]:
-
Full-space mode shape matrix
- [T]:
-
Transformation matrix
- [RTOa]:
-
Real-time operating data at reduced-space
- [ERTOn]:
-
Expanded real-time operating data
- {Xi} and {Xi}:
-
Displacement vectors i and j
- {RTOi} and {RTOj}:
-
Displacement time traces for points i and j
References
Malkin M (2014) Reliability trends. In: Sandia National Laboratories wind turbine blade workshop, Albuquerque
Helfrick MN, Niezrecki C, Avitabile P, Schmidt T (2011) 3D digital image correlation methods for full-field vibration measurement. Mech Syst Signal Process 25:917–927. doi:10.1016/j.ymssp.2010.08.013
Siebert T, Crompton MJ (2010) Application of high speed digital image correlation for vibration mode shape analysis. In: SEM annual conference and exposition on experimental and applied mechanics 2010, Indianapolis, pp 1776–1783
Warren C, Niezrecki C, Avitabile P, Pingle P (2011) Comparison of FRF measurements and mode shapes determined using optically image based, laser, and accelerometer measurements. Mech Syst Signal Process 25:2191–2202. doi:10.1016/j.ymssp.2011.01.018
Baqersad J, Carr J, Lundstrom T, Niezrecki C, Avitabile P, Slattery M (2012) Dynamic characteristics of a wind turbine blade using 3D digital image correlation. In: Health monitoring of structural and biological systems 2012, San Diego. doi:10.1117/12.915377
Carr J, Baqersad J, Niezrecki C, Avitabile P, Slattery M (2012) Dynamic stress–strain on turbine blades using digital image correlation techniques part 2: dynamic measurements. In: 30th IMAC, a conference on structural dynamics 2012, Jacksonville, pp 221–226. doi:10.1007/978-1-4614-2422-2_21
Carr J, Baqersad J, Niezrecki C, Avitabile P, Slattery M (2012) Dynamic stress–strain on turbine blade using digital image correlation techniques part 1: static load and calibration. In: 30th IMAC, a conference on structural dynamics 2012, Jacksonville, pp 215–220. doi:10.1007/978-1-4614-2422-2_20
Poozesh P, Baqersad J, Niezrecki C, Harvey E, Yarala R (2014) Full field inspection of a utility scale wind turbine blade using digital image correlation. CAMX, Orlando
Helfrick MN, Pingle P, Niezrecki C, Avitabile P (2009) Optical non-contacting vibration measurement of rotating turbine blades. In: 27th conference and exposition on structural dynamics 2009, IMAC XXVII, Orlando
Wang W, Mottershead JE, Siebert T, Pipino A (2012) Frequency response functions of shape features from full-field vibration measurements using digital image correlation. Mech Syst Signal Process 28:333–347. doi:10.1016/j.ymssp.2011.11.023
Wang W, Mottershead JE (2013) Adaptive moment descriptors for full-field strain and displacement measurements. J Strain Anal Eng Des 48:16–35
Wang W, Mottershead JE, Ihle A, Siebert T, Reinhard Schubach H (2011) Finite element model updating from full-field vibration measurement using digital image correlation. J Sound Vib 330:1599–1620
Wang W, Mottershead JE, Patterson E, Siebert T, Ihle A (2013) Model updating using shape descriptors from full-field images. In: Conference proceedings of the Society for Experimental Mechanics series, pp 425–436
Lundstrom T, Baqersad J, Niezrecki C, Avitabile P (2012) Using high-speed stereophotogrammetry techniques to extract shape information from wind turbine/rotor operating data. In: 30th IMAC, a conference on structural dynamics 2012, Jacksonville, pp 269–275. doi:10.1007/978-1-4614-2419-2_26
Warren C, Niezrecki C, Avitabile P (2011) Determination of wind turbine operating deflection shapes using full-field 3D point-tracking. In: 29th IMAC, a conference on structural dynamics 2011, Jacksonville, pp 217–226
Lundstrom T, Baqersad J, Niezrecki C (2013) Using high-speed stereophotogrammetry to collect operating data on a Robinson R44 Helicopter. In: 31st international modal analysis conference on structural dynamics, IMAC 2013, Garden Grove, pp 401–410. doi:10.1007/978-1-4614-6546-1_44
Olson LE, Abrego AI, Barrows DA, Burner AW (2010) Blade deflection measurements of a full-scale UH-60A rotor system. In: AHS aeromechanics specialists conference 2010, San Francisco, pp 738–747
Schneider O (2005) Analysis of SPR measurements from HART II. Aerosp Sci Technol 9:409–420. doi:10.1016/j.ast.2005.01.013
Schneider O, Van der Wall BG, Pengel K (2003) HART II blade motion measured by stereo pattern recognition (SPR). In: American Helicopter Society 59th annual forum, Phoenix
Tessler A, Spangler JL (2003) A variational principle for reconstruction of elastic deformations in shear deformable plates and shells. National Aeronautics and Space Administration, Langley Research Center, Hampton
Tessler A (2007) Structural analysis methods for structural health management of future aerospace vehicles. Key Eng Mater 347:57–66
Tessler A, Spangler JL (2005) A least-squares variational method for full-field reconstruction of elastic deformations in shear-deformable plates and shells. Comput Methods Appl Mech Eng, Uxbridge, England, 194:327–339. doi:10.1016/j.cma.2004.03.015
Chipman C, Avitabile P (2012) Expansion of transient operating data. Mech Syst Signal Process 31:1–12. doi:10.1016/j.ymssp.2012.04.013
Pingle P (2010) Prediction of full-field dynamic stress–strain from limited sets of measured displacement data. In: Mechanical Engineering Departmentz,Ph.D. Thesis, University of Massachusetts Lowell, Lowell, MA
Carr J, Baqersad J, Niezrecki C, Avitabile P, Slattery M (2013) Predicting dynamic strain on wind turbine blade using digital image correlation techniques in conjunction with analytical expansion methodologies. In: 31st international modal analysis conference on structural dynamics, IMAC 2013, Garden Grove, CA, pp 295–302. doi:10.1007/978-1-4614-6546-1_31
Iliopoulos AN, Devriendt C, Iliopoulos SN, Van Hemelrijck D (2014) Continuous fatigue assessment of offshore wind turbines using a stress prediction technique. In: SPIE/NDE, San Diego, pp 90640S-90640S-90611
Avitabile P, Obando SE, Truong K (2014) Full field dynamic deflection and strain for linear components connected with nonlinear connectors. In: International conference on noise and vibration engineering (ISMA2014), Leuven, Belgium
Harvie J, Obando S, Avitabile P (2013) Reduced order system model nonlinear response and expansion for full field results. In: Eleventh international conference on recent advances in structural dynamics, Pisa
Bogert PB, Haugse E, Gehrki RE (2003) Structural shape identification from experimental strains using a modal transformation technique. In: 44th AIAA/ASME/ASCE/AHS/ASC structures, structural dynamics, and materials conference
Derkevorkian A, Masri SF, Alvarenga J, Boussalis H, Bakalyar J, Lance Richards W (2013) Strain-based deformation shape-estimation algorithm for control and monitoring applications. AIAA J 51:2231–2240. doi:10.2514/1.10275
Chierichetti M, Ruzzene M (2012) Dynamic displacement field reconstruction through a limited set of measurements: application to plates. J Sound Vib 331:4713–4728
Chierichetti M (2014) Load and response identification for a nonlinear flexible structure subject to harmonic loads. J Comput Nonlinear Dyn 9:011009. doi:10.1115/1.4025505
Guyan RJ (1965) Reduction of stiffness and mass matrices. AIAA J 3:380–380
Kidder RL (1973) Reduction of structural frequency equations. AIAA J 11:892–892
O’Callahan JC (1989) A procedure for an improved reduced system (IRS) model. In: Proceedings of the 7th international modal analysis conference. Union College Press, Schenectady, pp 17–21
O’Callahan J, Avitabile P, Riemer R (1989) System equivalent reduction expansion process (SEREP). In: 7th IMAC, a conference on structural dynamics 1989, pp 29–37
Allemang RJ, Brown DL (1989) Correlation coefficient for modal vector analysis. In: Proceedings of the 1st international modal analysis conference & exhibit. Union College, Orlando, pp 110–116
(2011) PONTOS v6.3. GOM mbH, Braunschweig
(2010) Abaqus/CAE 6.10-2. Dassault System
Baqersad J, Poozesh P, Niezrecki C, Avitabile P (2014) Comparison of modal parameters extracted using MIMO, SIMO, and impact hammer tests on a three-bladed wind Turbine. In: 32th IMAC, a conference on structural dynamics, Orlando. doi:10.1007/978-3-319-04774-4_19
Baqersad J, Niezrecki C, Avitabile P, Slattery M (2013) Dynamic characterization of a free-freewind turbine blade assembly. In: 31st international modal analysis conference on structural dynamics, IMAC 2013, Garden Grove, pp 303–312. doi:10.1007/978-1-4614-6546-1_32
Pingle P, Avitabile P (2011) Full field dynamic stress/strain from limited sets of measured data. In: 29th IMAC, a conference on structural dynamics 2011, Jacksonville, pp 187–200
Acknowledgements
This research presented in this paper is partly supported by the National Science Foundation under Grant Number 1230884 (Achieving a Sustainable Energy Pathway for Wind Turbine Blade Manufacturing). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.
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Baqersad, J., Poozesh, P., Niezrecki, C., Avitabile, P. (2015). Predicting Full-Field Strain on a Wind Turbine for Arbitrary Excitation Using Displacements of Optical Targets Measured with Photogrammetry. In: Allemang, R. (eds) Special Topics in Structural Dynamics, Volume 6. Conference Proceedings of the Society for Experimental Mechanics Series. Springer, Cham. https://doi.org/10.1007/978-3-319-15048-2_10
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DOI: https://doi.org/10.1007/978-3-319-15048-2_10
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