Parametric identification of a time-varying structure based on vector vibration response measurements

The problem of parametric output-only identification of a time-varying structure based on vector random vibration signal measurements is considered. A functional series vector time-dependent autoregressive moving average (FS-VTARMA) method is introduced and employed for the identification of a “bridge-like” laboratory structure consisting of a beam and a moving mass. The identification is based on three simultaneously measured vibration response signals obtained during a single experiment. The method is judged against baseline modelling based on multiple “frozen-configuration” stationary experiments, and is shown to be effective and capable of accurately tracking the dynamics. Additional comparisons with a recursive pseudo-linear regression VTARMA (PLR-VTARMA) method and a short time canonical variate analysis (ST-CVA) subspace method are made and demonstrate the method's superior achievable accuracy and model parsimony.