The EMI technique of PZT has received more and more attention due to its merits in adapting to on-line monitoring.The E/M coupling speciality

PZT-structure interaction model

basic principle of EMI technique and the current status of research in civil engineering are presented in this paper.The smart health monitoring method by using PZT technique has potentially extensive usage in the future.However

owing to the short history of the study of EMI technique

the use of this technique is mostly limited in laboratory.Some of the key problems to be solved associated with this technique are summarized in this paper.