Advertisement

Using Laser Vibrometry for Precise FRF Measurements in Experimental Substructuring

  • Francesco TrainottiEmail author
  • Tobias F. C. Berninger
  • Daniel J. Rixen
Conference paper
Part of the Conference Proceedings of the Society for Experimental Mechanics Series book series (CPSEMS)

Abstract

The acquisition of high quality FRF measurements is a key factor for a successful implementation of coupling/decoupling techniques in Experimental Dynamic Substructuring. Although the use of piezo accelerometers as response transducers is very popular for impact testing due to its easy and fast implementation, the level of accuracy could not be adequate in certain applications. The laser technology provides a non-invasive alternative to standard piezo devices. The choice of a non-contact measurement technique allows to minimize the impact of external dynamic systems on the test component during the measurement process. In this paper, a validation of Lagrange Multiplier—Frequency Based Substructuring coupling by means of a Virtual Point Reduction is performed on a benchmark structure with a non-stiff interface. The necessary FRF data is acquired twice, using accelerometers and a laser Doppler vibrometer respectively. Both coupling results are compared to each other and are shown to match very well simulation data up to a high frequency range. The results underline the potential of high quality, non-intrusive measurements for Frequency Based Substructuring.

Keywords

Experimental dynamics Dynamic Substructuring Frequency Based Substructuring Virtual Point Transformation FRF measurements Laser vibrometry 

References

  1. 1.
    De Klerk, D., Rixen, D.J., Voormeeren, S.: General framework for dynamic substructuring: history, review and classification of techniques. AIAA J. 46.5, 1169–1181 (2008)CrossRefGoogle Scholar
  2. 2.
    Van der Sejis, M., Van der Bosch, D., Rixen, D., De Klerk, D.: An improved methodology for the virtual point transformation of measured frequency response functions in dynamic substructuring. In: COMPDYN (2013)Google Scholar
  3. 3.
    Lyons, R.G.: Understanding Digital Signal Processing, 1st edn. Addison-Wesley Longman, Boston (1997)Google Scholar
  4. 4.
    Brown, D.L., Allemang, R.J., Phillips, A.W.: Forty years of use and abuse of impact testing: a practical guide to making good FRF measurements. In: Experimental Techniques, Rotating Machinery, and Acoustics. Proceeding of the Society for Experimental Mechanics, vol. 8 (2015)Google Scholar
  5. 5.
    Døssing, O., (Firm), B.K.: Structural Testing: Mechanical mobility measurements, pt. 1. Bruël & Kjær, Nærum (1988)Google Scholar
  6. 6.
    Rixen, D.: How measurement inaccuracies induce spurious peaks in frequency based substructuring. In: Proceedings of the Twenty Sixth International Modal Analysis Conference, Orlando, FL. Society for Experimental Mechanics, Bethel (2008)Google Scholar
  7. 7.
    Voormeeren, S.N., De Klerk, D., Rixen, D.J.: Uncertainty quantification in experimental frequency based substructuring. Mech. Syst. Signal Process. 24, 106–118, (2010)CrossRefGoogle Scholar
  8. 8.
    De Klerk, D., Rixen, D.J., De Jong, J.: The frequency based substructuring (FBS) method reformulated according to the dual domain decomposition method. In: 24th International Modal Analysis Conference, St. Louis (2006)Google Scholar
  9. 9.
    Van der Sejis, M.: Experimental Dynamic Substructuring. PhD thesis, Delft University of Technology (2016)Google Scholar
  10. 10.
    De Klerk, D.: Solving the RDoF problem in experimental dynamic substructuring. In: Proceedings of the 26th International Modal Analysis Conference (IMAC) (2008)Google Scholar
  11. 11.
    Häußler, M., Rixen, D.: Optimal transformation of frequency response functions on interface deformation modes. In: Dynamics of Coupled Structures, vol. 4, pp. 25–237. Springer, Cham (2017)CrossRefGoogle Scholar
  12. 12.
    Company, H.P.: The Fundamentals of Modal Testing: Application Note 243-3. Hewlett Packard Company, Palo Alto (1986)Google Scholar
  13. 13.
    Rothberg, S., Allen, M., Castellini, P., DiMaio, D., Dirckx, J., Ewins, D., Halkon, B., Muyshondt, P., Paone, N., Ryan, T., Steger, H., Tomasini, E., Vanlanduit, S., Vignola, J.: An international review of laser Doppler vibrometry: making light work of vibration measurement. Opt. Lasers Eng. 99, 11–22 (2017). https://doi.org/10.1016/j.optlaseng.2016.10.023 CrossRefGoogle Scholar
  14. 14.
    Maierhofer, J., El Mahmoudi, A., Rixen, D.J.: Development of a lowcost automatic modal hammer for applicaions in substructuring. In: Proceedings of the 37th International Modal Analysis Conference (IMAC) (2019)Google Scholar

Copyright information

© Society for Experimental Mechanics, Inc. 2020

Authors and Affiliations

  • Francesco Trainotti
    • 1
    Email author
  • Tobias F. C. Berninger
    • 1
  • Daniel J. Rixen
    • 1
  1. 1.Faculty of Mechanical EngineeringTechnical University of MunichGarchingGermany

Personalised recommendations