Improved Substructure Identification Through Use of an Active Control Device

Abstract

AbstractIncreasingly, researchers turn to substructure identification for civil structural health monitoring for a variety of reasons. First, substructure identification provides inherent damage localization. Second, substructure identification provides greater numerical conditioning than full structure identification because only a small subset of the degrees of freedom are considered in each analysis. Third, substructure identification is perfectly suited for a decentralized implementation within a network of wireless sensors. This implementation can realize cost savings in installation and operation.While the benefits of substructure identification are many-fold, current research shows that certain structure-substructure combinations admit poor performance. Research demonstrates that single story substructures in a shear building are poorly identified (if at all) when interstory acceleration response is low in a specific frequency range. This result shows that portions of the structure are unable to be identified properly with substructure identification.To overcome these results, this paper temporarily re-purposes a structural control device to change the global dynamics of the structure to improve substructure identification at a particular story. A control law for an active mass damper is developed to increase the interstory response at a particular story, which, when implemented, will improve substructure identification of that story. The control law is developed in simulation and will later be tested experimentally on a four story, 12 ft. steel building excited by base motion.KeywordsStructural Health MonitoringStructural ControlStructural DynamicsDamage DetectionExperimental Methods