TY - GEN
T1 - Time-frequency domain modal parameter estimation of time-varying structures using a two-step least square estimator
AU - Zhou, Si Da
AU - Heylen, Ward
AU - Sas, Paul
AU - Liu, Li
PY - 2012
Y1 - 2012
N2 - Under natural stochastic excitations, responses of time-varying structures are always nonstationary stochastic signals, of which spectra change with time. This paper studies the time-dependent power spectrum density based on timefrequency analysis. Based on the time-dependent power spectrum density, a mathematical model of the time-frequency-domain two-step least square modal parameter estimator for time-varying structures is presented. In the first-step estimation, the modal parameters at each time instant are estimated using the least square complex frequency-domain method. Furthermore, the estimated modal parameters are sifted and sorted. Based on the sifted and sorted modal parameters, the time-varying resonance frequency, damping ratio and operational mode shapes are estimated in the second-step estimation. A numerical simulation example and a group of experiments validate this two-step least square modal parameter estimator for time-varying structures.
AB - Under natural stochastic excitations, responses of time-varying structures are always nonstationary stochastic signals, of which spectra change with time. This paper studies the time-dependent power spectrum density based on timefrequency analysis. Based on the time-dependent power spectrum density, a mathematical model of the time-frequency-domain two-step least square modal parameter estimator for time-varying structures is presented. In the first-step estimation, the modal parameters at each time instant are estimated using the least square complex frequency-domain method. Furthermore, the estimated modal parameters are sifted and sorted. Based on the sifted and sorted modal parameters, the time-varying resonance frequency, damping ratio and operational mode shapes are estimated in the second-step estimation. A numerical simulation example and a group of experiments validate this two-step least square modal parameter estimator for time-varying structures.
KW - Modal parameter estimation
KW - Time-frequency analysis
KW - Time-varying structure
KW - Two-step least square
UR - https://www.scopus.com/pages/publications/84864009577
U2 - 10.1007/978-1-4614-2425-3_8
DO - 10.1007/978-1-4614-2425-3_8
M3 - Conference contribution
AN - SCOPUS:84864009577
SN - 9781461424246
T3 - Conference Proceedings of the Society for Experimental Mechanics Series
SP - 65
EP - 75
BT - Topics in Modal Analysis I - Proceedings of the 30th IMAC, A Conference on Structural Dynamics, 2012
T2 - 30th IMAC, A Conference on Structural Dynamics, 2012
Y2 - 30 January 2012 through 2 February 2012
ER -