Structural damage identification using piezoelectric sensors

In this paper, a two-stage damage identification method has been proposed using the data obtained from piezoelectric sensors. In the first stage, a first-order approximation technique is presented for numerically predicting the transient response of electrical potential change on sensors caused by damages. Both numerical and experimental data in the time domain are transformed into the frequency domain using the FFT technique. The damage locations can then be detected by matching the numerical data and the experimental data in the frequency domain through a proposed detection technique. After identifying the possible damage locations, in the second stage, an iterative estimation scheme for solving nonlinear optimization programming problems, based on the quadratic programming technique, is put forward to predict damage extents. A beam example has been employed to illustrate the effectiveness of the algorithm numerically. Furthermore, various investigations, such as the accuracy of the proposed first-order approximation technique, the influences of the excitation frequency of external force, and modelling errors and measurement noises on the results have been carried out