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Potential and Limitation of a Nonlinear Modal Testing Method for Friction-Damped Systems

  • Maren ScheelEmail author
  • Tobias Schulz
  • Malte Krack
Conference paper
Part of the Conference Proceedings of the Society for Experimental Mechanics Series book series (CPSEMS)

Abstract

Experimental nonlinear modal analysis has been applied successfully, mainly on structures with stiffness nonlinearities. However, it remains a challenge to experimentally extract a nonlinear modal model of structures with nonlinear damping, such as friction. To systematically investigate a modal testing method for friction-damped structures, we introduce a new test specimen. The specimen is a beam that is clamped on one side and offers six possible locations to induce friction. Changing the friction location varies the significance of the non-linear effects, that is, frequency shift, increase in damping and change of mode shapes. We apply experimental modal analysis with one excitation point to track the properties of one mode from full stick to macro slip. To assess the quality and validity of the extracted modal model, we compare predicted steady-state vibrations with frequency response measurements close to resonance. Based on these results, we discuss the potential and limitation of the applied modal testing approach.

Keywords

Nonlinear modes Modal analysis Force appropriation Jointed structures Nonlinear system identification 

References

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    Krack, M.: Nonlinear modal analysis of nonconservative systems: extension of the periodic motion concept. Comput. Struct. 154, 59–71 (2015)CrossRefGoogle Scholar
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    Scheel, M. et al.: A phase resonance approach for modal testing of structures with nonlinear dissipation. J. Sound Vib. 435, 56–73 (2018)CrossRefGoogle Scholar
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    Scheel, M. et al.: System identification of jointed structures: nonlinear modal testing vs. state-space model identification. In: Nonlinear Dynamics, vol. 1, pp. 159–161. Springer, Cham (2019)Google Scholar
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    Schulz, T.: Konzeption, Auslegung und Konstruktion eines Versuchsstandes für die Untersuchung dissipativer Strukturen (Design and construction of a test rig for the investigation on dissipative structures) Master’s thesis. University of Stuttgart, Germany (2018)Google Scholar
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    Scheel, M. et al.: Nonlinear Modal Testing of a Strongly Friction-damped Beam (in preparation)Google Scholar

Copyright information

© Society for Experimental Mechanics, Inc. 2020

Authors and Affiliations

  1. 1.Institute of Aircraft Propulsion SystemsUniversity of StuttgartStuttgartGermany
  2. 2.MesH Engineering GmbHStuttgartGermany

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