Structural damage identification for thin plates using smart piezoelectric transducers

An impedance-based structural damage identification method for thin plates is presented in this paper using piezoelectric ceramic (PZT) transducers. The local damages are characterized by introducing a damage parameter in each finite element. A two-dimensional electromechanical impedance model is proposed to predict the electric admittance of the PZT transducer bonded to the plates. The general equations for generating structural dynamic stiffness from normal modes are formulated based on finite element analysis. The first-order perturbation method is introduced to obtain the electric admittance change on PZT transducers due to damage. A damage identification scheme for solving nonlinear optimization problem is proposed to locate and quantify the damage by matching the numerical and experimental electric admittance change on PZT transducers. The proposed technique is verified through numerically simulated damage identification tests.