Experimental identification of structural uncertainty – An assessment of conventional and non-conventional stochastic identification techniques

An experimental assessment of several stochastic identification methods with respect to their ability in capturing the structural uncertainty is presented via their application to a lightweight aluminum plate structure. The uncertainty analysis is based on both non-parametric (Welch based) and parametric (VARX based) conventional stochastic identification methods and also on a CCP-VARX based method which operates on multiple data records. The methods effectiveness is assessed via multiple series of experiments under similar operating conditions, focusing on both in-series and inter-series uncertainty. The results of the study indicate: (a) small, yet statistically significant, in-series uncertainty and larger inter-series uncertainty; (b) inability of both the conventional VARX and CCP-VARX parametric methods to fully describe multiple experiment uncertainty through a single identified model.