Damage detection in beam through change in measured frequency and undamaged curvature mode shape

Abstract

ABSTRACTThis paper develops and presents a technique on the identification of the damage location and depth in a beam using a frequency contour method. Unlike the frequency contour methods presented in the literature, the one presented in this work does not require neither the solving of the governing differential equation analytically to obtain the contour lines, nor the calculation of the frequencies by varying all damage severities and locations in order to use an inverse problem to plot the contours. In other words, the detection method does not require the modelling of the damage. In this work, a contour line is plotted using only the value of the changes in the measured natural frequencies and the vectors of the curvature mode shapes of the intact structure which can be calculated numerically or can be derived from the measured mode shapes. In order to verify the practical applicability of the developed theoretical method, a numerical simulation and an experimental framework on cantilever beam have been designed and the results confirm the applicability of the developed method in the real applications.