Open AccessA COMPARISON OF TWO MODAL ANALYSIS METHODS: AN IMPACT HAMMER VERSUS LASER VIBROMETRY
Author(s) -
Jakub Krejčí,
Petr Beneš
Publication year - 2020
Publication title -
acta polytechnica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.207
H-Index - 15
eISSN - 1805-2363
pISSN - 1210-2709
DOI - 10.14311/ap.2020.60.0420
Subject(s) - modal , hammer , modal analysis , cantilever , modal testing , natural frequency , acoustics , repeatability , interferometry , accelerometer , structural engineering , finite element method , optics , engineering , computer science , materials science , mathematics , physics , vibration , statistics , polymer chemistry , operating system
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.