High frequency piezoelectric signatures for diagnosis of seismic/blast induced structural damages

The last three decades have witnessed the construction of vast infrastructural facilities, especially from reinforced concrete (RC), in many parts of the world. This has necessitated the development of automated, real-time and online structural health monitoring systems, which can provide a cost-effective alternative to the traditional visual inspection. This paper discusses the feasibility of employing mechatronic conductance signatures of surface bonded piezoelectric-ceramic (PZT) patches in monitoring the conditions of RC structures subjected to base vibrations, such as those caused by earthquakes and underground blasts. Specifically, flexural and shear cracks, two prominent types of incipient damages in RC structures, were considered. The PZT patches were found to be able to identify both damage types much earlier than the conventional low frequency dynamic response techniques. Therefore, the PZT patches can be potentially employed to monitor the health of RC frames, which constitute the main skeletons of most large civil structures. (C) 2004 Elsevier Ltd. All rights reserved.