Wind and Structures

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A 3-DOF forced vibration system for time-domain aeroelastic parameter identification

  • Sauder, Heather Scot (CPP Wind Engineering) ;
  • Sarkar, Partha P. (Department of Aerospace Engineering, Iowa State University)
  • Received : 2016.11.20
  • Accepted : 2017.05.07
  • Published : 2017.05.25
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Abstract

A novel three-degree-of-freedom (DOF) forced vibration system has been developed for identification of aeroelastic (self-excited) load parameters used in time-domain response analysis of wind-excited flexible structures. This system is capable of forcing sinusoidal motions on a section model of a structure that is used in wind tunnel aeroelastic studies along all three degrees of freedom - along-wind, cross-wind, and torsional - simultaneously or in any combination thereof. It utilizes three linear actuators to force vibrations at a consistent frequency but varying amplitudes between the three. This system was designed to identify all the parameters, namely, aeroelastic- damping and stiffness that appear in self-excited (motion-dependent) load formulation either in time-domain (rational functions) or frequency-domain (flutter derivatives). Relatively large displacements (at low frequencies) can be generated by the system, if required. Results from three experiments, airfoil, streamlined bridge deck and a bluff-shaped bridge deck, are presented to demonstrate the functionality and robustness of the system and its applicability to multiple cross-section types. The system will allow routine identification of aeroelastic parameters through wind tunnel tests that can be used to predict response of flexible structures in extreme and transient wind conditions.

Keywords

Acknowledgement

Supported by : U.S. National Science Foundation

References

  1. Cao, B. and Sarkar, P.P. (2012), "Identification of rational functions using two-degree-of-freedom model by forced vibration method", Eng. Struct., 43, 21-30. https://doi.org/10.1016/j.engstruct.2012.05.003
  2. Chowdhury, A.G. and Sarkar, P.P. (2003), "A new technique for identification of eighteen flutter derivatives using a three-degree-of-freedom section model", Eng. Struct., 25, 1763-1772. https://doi.org/10.1016/j.engstruct.2003.07.002
  3. Chowdhury, A.G. and Sarkar, P.P. (2004), "Identification of eighteen flutter derivatives of an airfoil and a bridge deck", Wind Struct., 7(3), 187-202. https://doi.org/10.12989/was.2004.7.3.187
  4. Chowdhury, A.G. and Sarkar, P.P. (2005), "Experimental identification of rational function coefficients for time domain flutter analysis," Engineering Structures, The Journal of Earthquake, Wind and Ocean Engineering, 27, 1349-1364.
  5. Dallaire, P.O., Taylor, Z.J. and Stoyanoff S. (2016), "Sectional model tests of tandem bridge decks in dynamic suspension systems", Proceedings of the 8th International Colloquium on Bluff Body Aerodynamics and Applications, Boston, MA.
  6. Davenport, A.G. (1962), "Buffeting of a suspension bridge by storm winds", J. Struct. Eng. - ASCE, 88(3), 233-268.
  7. Davenport, A.G., Isyumov, N. and Miyata, T. (1971), "The experimental determination of the response of suspension bridges to turbulent wind", Proceedings of the 3rd International Conference on Wind Effects on Buildings and Structures, Tokyo, Japan.
  8. Karpel, M. (1982), "Design for active flutter suppression and gust alleviation using state-space aeroelastic modeling", J. Aircraft, 19(3), 221-227. https://doi.org/10.2514/3.57379
  9. Matsumoto, M. (1996), "Aerodynamic damping of prisms", J. Wind Eng. Ind. Aerod., 59, 159-175 https://doi.org/10.1016/0167-6105(96)00005-0
  10. Permata, R., Yonamine, K., Hattori, H. and Shirato, H. (2013), "Aerodynamics and flutter stability of slender bridge deck with double slot and porous cavity", Proceedings of the 6th Civil Engineering Conference in Asia Region.
  11. Prud'homme, S., Legeron, F. and Laneville, A. (2015), "Effect of sway movement and motions axis on flutter and vortex induced vibration in a 3 DOF wind tunnel sectional test", J. Wind Eng. Ind. Aerod., 136, 82-88. https://doi.org/10.1016/j.jweia.2014.11.001
  12. Roger, K. (1977), "Airplane math modeling methods for active control design", AGARD-CP-228.
  13. Sarkar, P.P., Jones, N.P. and Scanlan, R.H. (1994), "Identification of aeroelastic parameters of flexible bridges", J. Eng. Mech. -ASCE, 120(8).
  14. Sarkar, P.P., Gan Chowdhury, A. and Gardner, T.B. (2004), "A novel elastic suspension system for wind tunnel section model studies", J. Wind Eng. Ind. Aerod., 92, 23-40. https://doi.org/10.1016/j.jweia.2003.09.036
  15. Sauder, H.S. and Sarkar, P.P. (2015), "Time-domain aeroelastic loads and response of wind turbine blades", Proceedings of the 14th Int. Conf. on Wind Eng., Int. Association for Wind Eng., Porto Alegre, Brazil, June.
  16. Scanlan, R.H. and Tomko, J.J. (1971), "Airfoil and bridge deck flutter derivatives", J. Eng. Mech. Div., 97(6), 1717-1733.
  17. Scanlan. R.H., Jones, N.P. and Lorendeaux, O. (1997), "Comparison of taut-strip and section-model-based approaches in long-span bridge aerodynamics", J. Wind Eng. Ind. Aerod., 72, 275-287. https://doi.org/10.1016/S0167-6105(97)00250-X
  18. Scruton, C. (1981), An Introduction To Wind Effects On Structures, Oxford University Press, Engineering Design Guides 40.
  19. Strouhal, V. (1878), "On one particular way of tone generation", Annalen der Physik und Chemie (Leipzig), ser. 3.

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