M. Salehi - PhD candidate, Isfahan University of Technology
S. Ziaei-Rad - Professor, Isfahan University of Technology;
M. Ghayour - Associate professor, Isfahan University of Technology
M.A Vaziri-Zanjani - ۴Assistant professor, Amirkabir University of Technology

Most of methods developed for detecting damage in a structure using measured modal parameters require a correlated finite element model, or at least, modal data of the structure for the intact state as baseline. For beam-like structures, curvature potential techniques, e.g., mode shape curvature and flexibility curvature have been applied to localize damage. In this paper, an approximate flexibility matrix has been derived using afew number of vibration modes whose columns are referred as flexibility shapes. Next, a damage localization method based on changes in flexibility shapes as well as its curvature is developed. Differential Quadrature Method has been implemented to obtain the curvatures of flexibility shapes. It was shown that the method works well using damaged model. To reduce the error due to differentiation of experimental data, a moving curve fit method has been implemented on flexibility shapes. The method is demonstrated through numerical and experimental case studies.

Modal Analysis, Modal Testing, Damage Detection