Electro-mechanical Impedance Modeling for Health Monitoring of a Damaged Thin Plate

This paper presents an electro-mechanical impedance (EMI) model for damage identification of thin plate structures. Firstly, a damaged thin plate with a pair of piezoceramic (PZT) transducers bonded on the opposite sides is considered. And the pure bending vibration of the plate actuated by the PZT patches is analyzed. Then, a method which combines the p-Ritz method and the matrix perturbation method is proposed to obtain the approximate analytic relation between the mechanical impedance of the damaged plate and the physical parameters of damage. Based on the interaction model between the PZT and the plate, an analytic relation between the admittance of PZT and the physical parameters of damage can be derived. Finally, numerical examples are used to verify the validity and feasibility of the proposed EMI model. The results indicate that the EMI model is more applicable for the thin plate structures with small damage.