Damage Detection Using Emi

Damage detection and health monitoring of structures and equipment poses challenges for scientists and engineers. The inspection and dismantling of these items is expensive and time consuming, thus it requires techniques to localize and to estimate the severity of damage in an on-line fashion. In this work, Electro Mechanical Impedance (EMI) is used to provide information about damage location and severity. Piezoelectric (PZT) smart materials are used to tap onto structures and to detect impedance changes due to internal damage that is monitored experimentally. The experimental results showed that there is a correlation between the frequency shift of the first peak of EMI signature and the location of the damage, an empirical metric relation was devised for this change and resulted in an error varying between -22% to 16%. Moreover, results showed that the larger damages produce larger change in measured admittance values.