An fast Fourier transform–based correlation coefficient approach for structural damage diagnosis

We present a novel approach to evaluating mechanical features of structures using correlation coefficients and fast Fourier transform analysis. Although correlation coefficient is always a sensitive parameter to changes of mechanical properties of real structures, it is rarely used due to high complication in data collection. To overcome this drawback, we propose fast Fourier transform analysis to increase the sensitivity of correlation coefficient, simplify calculation, and retain information from the original signal. Numerical results show that the present method not only detects relation between changes in structure with progression of defects but also locates their position. An fast Fourier transform–based correlation coefficient approach provides evaluations in both real bridge structures and experimental models. This study can serve as reference for analyzing, evaluating, and identifying working status of real structures.