Response modification to improve the parameter identification of shear structures: An experimental verification

Structural control systems are installed in structures to mitigate large structural vibration during strong earthquakes or high-speed winds. During the majority of time when no such hazards are present, the role of these control systems can be temporarily shifted to facilitate more accurate characterization of structural health. This novel use of control devices provides another benefit of installing control systems in buildings at minimum extra cost. The authors proposed, in previous studies, a substructure identification method applicable to shear structures. The error analysis proved that the identification accuracy of this method can be improved if the responses of the substructure being identified are changed in a specific way by using feedback vibration control. Exploiting these results, an alternative control algorithm is designed to improve the identification accuracy. A numerical simulation demonstrates that the new controlled identification method, using semiactive braces, can greatly improve the accuracy of structural parameter estimation. To verify experimentally that dynamic response changes can improve identification accuracy, shake table tests are performed on a two-story shear structure model with passive modifications; the results show that the structural parameters are more accurately identified with these changes than without.