Experimental dynamic characterization

Bladed wheel dynamic characterization is a crucial issue to avoid resonance excitations. The experimental activity is essential to validate the models and to account for manufacturing imperfections, which may cause relevant mistuning of the components. The research activity is focused on the development of two test benches aimed at performing both experimental modal analysis and experimental harmonic response analysis. The first task is faced through an anthropomorphic robotic station, equipped with a single-point Laser Doppler Vibrometer. The setup allows to perform automatic measurements, which drastically increase positioning accuracy and shorten testing time. The second task is faced through a dedicated test bench equipped with a shaker for each blade. The shaker themselves were developed to guarantee the needed performances. The test bench is controlled by electronic equipment which implement a closed loop control to guarantee the proper excitation of the structures. Both the test benches were developed to operate in the high frequency range, from 1 kHz to 10 kHz.

Experimental modal analysis test bench
Harmonic response analysis test bench

Research group
Paolo Neri, Ciro Santus, Leonardo Bertini

Main publications:

  • L. Bertini, P. Neri, C. Santus, A. Guglielmo, G. Mariotti, Analytical investigation of the SAFE diagram for bladed wheels, numerical and experimental validation, Journal of Sound and Vibration, Elsevier, 2014, Vol. 333, pp. 4771-4788, DOI: 10.1016/j.jsv.2014.04.061
  • L. Bertini, P. Neri, C. Santus, A. Guglielmo, Automated experimental modal analysis of bladed wheels with an anthropomorphic robotic station, Experimental Mechanics, Springer, 2016, Vol. 57, pp. 273-285, DOI: 10.1007/s11340-016-0223-5
  • P. Neri, Excitation device for high frequency vibration analysis: Design and test results, Journal of Vibration and Control, Sage, 2018, Vol. 24, pp. 4620-4629, DOI: 10.1177/1077546317731210
  • L. Bertini, B.D. Monelli, P. Neri, C. Santus, A. Guglielmo, Robot assisted modal analysis on a stationary bladed wheel, Proceedings of the ASME 2014 12th Biennial Conference on Engineering Systems Design and Analysis ESDA2014, June 25-27, 2014, Copenhagen, Denmark, DOI: 10.1115/ESDA2014-20636.
  • L. Bertini, P. Neri, C. Santus, A. Guglielmo, One exciter per sector test bench for bladed wheels harmonic response analysis, Proceedings of ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition, June 26-30 2017, Charlotte, NC, USA, DOI: 10.1115/GT2017-63628
  • L. Bertini, P. Neri, C. Santus, A. Guglielmo, Generalized SAFE diagram for mistuned bladed wheels, Journal of Engineering for Gas Turbines and Power, ASME, Submitted May 2019