A COMPARISON OF TWO MODAL ANALYSIS METHODS: AN IMPACT HAMMER VERSUS LASER VIBROMETRY

Authors

  • Jakub Krejčí Brno University of Technology, Faculty of Electrical Engineering and Communication, Department of Control and Instrumentation, Technická 3082/12, Královo Pole, 61600 Brno, Czech Republic
  • Petr Beneš Brno University of Technology, Faculty of Electrical Engineering and Communication, Department of Control and Instrumentation, Technická 3082/12, Královo Pole, 61600 Brno, Czech Republic

DOI:

https://doi.org/10.14311/AP.2020.60.0420

Keywords:

modal analysis, free beam, 2D interferometer, COMSOL, ModalVIEW

Abstract

This paper presents a comparative experimental-analytical study on the performance of Multi-Input Single-Output (MISO) and Single-Input Multi-Output (SIMO) techniques to identify the modal properties of a cantilever beam. A 2-D laser interferometry was employed to perform the SIMO modal test, while for the MISO test configuration, a conventional accelerometer was used to measure the response of the structure. Comparing the experimentally-measured natural frequencies with those calculated by the FEM model, a maximum difference of 4% between natural frequencies was observed. The repeatability of both techniques is also investigated in this paper and it is shown that the difference between modal properties identified under different operators is less than 0.5% for both the MISO and SIMO techniques.

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Published

2020-11-19

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