Developing a multi-mode PZT sensing solution for active SHM in concrete structures

Two damage detection and identification techniques are integrated in this work, including electromechanical impedance and guided waves methodologies, by using piezoelectric (PZT) patches bonded or embedded to the host structure. In particular, the electromechanical impedance has been used for identifying local damaged regions by monitoring the changes in structural mechanical properties, which are coupled with the electrical impedance of a PZT patch. In the guided wave propagation, one PZT patch acting as an actuator launches an elastic wave through the structure, which is can be measured by another PZT patch. The integration approach of these two methodologies is then straightforward because the same piezoelectric patch can be used for both methods. This integration approach is experimentally validated in this work by developing a reused and “multi-mode” sensing system for damage detection of concrete structures.