Advertisement

Scenario Based Approach for Load Identification

  • Michael VigsøEmail author
  • Marius Tarpø
  • Jannick B. Hansen
  • Rune Brincker
  • Christos T. Georgakis
Conference paper
Part of the Conference Proceedings of the Society for Experimental Mechanics Series book series (CPSEMS)

Abstract

In output only analysis the load identification has been a puzzle for several years. Different techniques have been purposed to cope with the inversion problem that lies within this field. However it has been shown, that most methods struggle to obtain robust and consistent results in cases of modal truncation and noise contaminated signals. In the light of these challenges, a scenario based method is proposed. This approach utilizes model updating along with mode shape expansion to obtain a reliable numerical model of the given structure. Then, by evaluating a series of rational load scenarios, it is possible to obtain a reasonable input identification – both the spatial distribution and the temporal variation of the load. The method is demonstrated numerically and experimentally.

Keywords

System identification Operational modal analysis Response estimation Modal truncation FE updating 

Notes

Acknowledgements

The authors acknowledge the funding received from Centre for Oil and Gas – DTU/Danish Hydrocarbon Research and Technology Centre (DHRTC).

References

  1. 1.
    Stevens, K.: Force identification problems – an overview. In: Proceedings of the SEM Spring Conference on Experimental Mechanics, pp. 838–844 (1987)Google Scholar
  2. 2.
    Brincker, R., Ventura, C.: Introduction to Operational Modal Analysis. Wiley, New York (2015)Google Scholar
  3. 3.
    Liu, Y., Shepard, W.: Dynamic force identification based on enhanced least squares and total least-squares scheme in the frequency domain. J. Sound Vib. 282, 37–60 (2005)Google Scholar
  4. 4.
    Aenlle, M., Brincker, R., Fernández, P., Fernández, A.: Load estimation from modal parameters. In: Proceedings of the 2nd International Operational Modal Analysis Conference, vol. 1, pp. 39–50 (2007)Google Scholar
  5. 5.
    Léger, P., Ricles, J.M., Robayo, L.J.: Reducing modal truncation error in the wave response analysis of offshore structures. Commun. Appl. Numer. Methods 6, 7–16 (1990)Google Scholar
  6. 6.
    Maes, K., Iliopoulos, A., Weijtjens, W., Devriendt, C., Lombaert, G.: Dynamic strain estimation for fatigue assessment of and offshore monopile wind turbine using filtering and modal expansion algorithms. Mech. Syst. Signal Process. 76–77, 592–611 (2016)Google Scholar
  7. 7.
    Maes, K., Smyth, Q.W., De Roeck, G., Lombaert, G.: Joint input-state estimation in structural dynamics. Mech. Syst. Signal Process. 70–71, 445–466 (2016)Google Scholar
  8. 8.
    Parloo, E., Verboven, P., Guillaume, P., van Overmeire, M.: Force identification by means of in-operation modal models. J. Sound Vib. 262, 161–173 (2002)Google Scholar
  9. 9.
    Wang, B., Chiu, C.: Determination of unknown impact force acting on a simply supported beam. Mech. Syst. Signal Process. 17(3), 683–704 (2003)Google Scholar
  10. 10.
    Lourens, E., Reynders, E., De Roeck, G., Degrande, G., Lombaert, G.: An argumented Kalman filter for force identification in structural dynamics. Mech. Syst. Signal Process. 27, 446–460 (2012)Google Scholar
  11. 11.
    O’Callahan, J., Avitabile, P., Riemer, R.: System equivalent reduction expansion process. In: Proceedings of the 7th International Modal Analysis Conference (IMAC) (1989)Google Scholar
  12. 12.
    Brincker, R., Skafte, A., Anelle, M., Sestieri, A., D’Ambrogio, W., Canteli, A.: A local correspondence principle for mode shapes in structural dynamics. Mech. Syst. Signal Process. 45, 91–104 (2014)Google Scholar
  13. 13.
    Brincker, R., Zhang, L., Andersen, P.: Modal identification from ambient responses using frequency domain decomposition. In: Proceedings of the International Modal Analysis Conference, IMAC, pp. 625–630 (2000)Google Scholar
  14. 14.
    Lyons, R.: Understanding Digital Signal Processing. Pearson Education, Upper Saddle River (2011)Google Scholar

Copyright information

© The Society for Experimental Mechanics, Inc. 2019

Authors and Affiliations

  • Michael Vigsø
    • 1
    Email author
  • Marius Tarpø
    • 1
  • Jannick B. Hansen
    • 1
  • Rune Brincker
    • 2
  • Christos T. Georgakis
    • 1
  1. 1.Aarhus UniversityAarhusDenmark
  2. 2.Technical University of DenmarkKongens LyngbyDenmark

Personalised recommendations