Damage Detection in a Cracked Rod Using High-Frequency Electro-Mechanical Impedance Signatures

Electro-mechanical impedance (EMI) analysis is conducted in the paper for a one-dimensional rod. Two identical PZT patches bonded symmetrically onto the top and bottom surfaces of the rod are activated in phase and hence a pure axial excitation is created. Based on the finite element software ANSYS, an electro-mechanical impedance (EMI) model for the coupled structural system consisting of the host rod, bonding layer and the piezoelectric patches is established for structural health monitoring. A comparison study with the mode superposition method usually employed in the conventional EMI model is implemented to validate the effectivity and accuracy of the proposed EMI model. Finally, the numerical results indicate that the cracks appearing in the structures can be detected by using the proposed analysis.