The experiment of substructure isolation and identification using local time series

For huge complex structures, it is difficult to obtain enough information which is required necessarily in their global monitoring. Aiming at this problem, a Substructure Isolation Method (SIM) is proposed for local damage identification. An isolated substructure is a virtual and independent structure, which is separated from a global structure by adding virtual supports on the substructure boundary to zero the substructure boundary responses. Correspondingly the interior responses of the isolated substructure are constructed and used to identify the local substructure damage equivalently. In order to reveal the essence of the Substructure Isolation Method and unify its basic concept, the way of arranging sub-time series is improved according to the SIM method based on impulse response, that is, sub-time series are extracted section by section, and then are arrayed into a Toeplitz matrix. In this way, it not only unifies the expression of SIM based on local time series and that based on impulse response, but also integrates the basic concept of SIM. An experiment of a cantilever beam is used to validate the efficiency and the practical application of this method. Both the substructure isolation and damage identification are performed successfully using local measured responses.