Identification of Minor Structural Damage Based on Electromechanical Impedance Sensitivity and Sparse Regularization

This paper proposes a structural damage identification approach based on model updating with electromechanical impedance sensitivity and the sparse regularization technique to identify the location and severity of minor damage in structures. The sensitivities of the resonance frequency shifts in the impedance responses with respect to the stiffness parameters of the host structure are calculated and used to identify the damage with a small number of resonance frequency shifts. Numerical verifications on a single lead zirconate titanate (PZT) transducer patch and a PZT on a narrow aluminum plate structure are conducted to validate the finite-element modeling technique to calculate the impedance. The effectiveness and performance of the proposed structural damage identification approach are demonstrated with numerical simulations on an aluminum plate model attached to a PZT transducer patch. The initial finite-element model and a limited number of resonance frequency shifts in the impedance responses are used for the identification. Sparse regularization, namely, the l1 regularization technique, is used for solving the inverse problem. Single and multiple damage scenarios are considered. The effects of noise in the measured impedance signals and the number of available frequency shifts on the performance of the proposed damage identification approach are investigated. The results demonstrate the performance and robustness of the proposed approach.