A Novel Method of Extracting Damage-Sensitive Feature for Electromechanical Impedance-Based Structural Health Monitoring

The electromechanical impedance (EMI) technique, which employs piezoelectric ceramic (PZT) patches as transducers, is emerging as an effective and powerful technique in structural health monitoring (SHM). This paper presents a novel method to extract the damage-sensitive feature (DSF) for EMI-based SHM. Firstly, the concept of effective drive point (EDP) impedance was introduced briefly. Secondly, a novel DSF was proposed as the ratio of the active parts of EDP admittances before and after damages. Finally, the effectiveness of the proposed DSF was experimentally verified. The results show that the novel method provides a sensitive feature for EMI-based SHM