Identifying Damage Location with Admittance Signatures of Smart Piezo-Transducers

Abstract

Modal analysis-based damage detection techniques that use only the first few modes are not sensitive to incipient damages. The alternative of using the conventional methods to extract natural frequencies and mode shapes for higher modes is also a difficult task. In this paper, the electromechanical (E/M) impedance method integrated with a finite element (FE) model is presented as a means for damage location identification using the higher modes. Damage location is identified by correlating the changes in natural frequencies at the higher modes with the corresponding mode shapes of the undamaged structure. The natural frequency shifts of the structure are obtained from the shifts in the peaks of the E/M admittance signatures of smart piezo-transducers bonded on to the host structure. The mode shapes are obtained from the equivalent FE model of the undamaged structure. Numerical and experimental investigations of the proposed method are presented.