A novel electromechanical impedance model for surface-bonded circular piezoelectric transducer

Abstract

The electromechanical impedance (EMI) technique is one of common used methods for damage diagnosis. However, the mechanism of EMI-based damage diagnosing is usually complicated and difficult to be comprehensively described. To solve this problem to a certain extent, a novel EMI model for describing the interaction between piezoelectric transducer (PZT) and host structure is developed in this paper. The developed EMI model has advantages of simplicity in formula and excellent precision in signatures prediction. An efficaciously equivalent SMD (Spring-Mass-Damping) system is adopted to obtain the local structural mechanical impedance (LSMI) and to calculate the equivalent parameters ( ) in the vicinity of PZT. To verify the effectiveness of the novel model, a series of experiments are separately conducted on the specimen under healthy condition and damage condition. Through comparing the predicted curves with the experimental ones, the effectiveness of the developed model is demonstrated when used for predicting signatures, especially for resistance signatures. The developed EMI model has shown the potential application in the field of structural health monitoring and damage diagnosis.