Defects influence in a negative way the service life of the structures. Thus, defect detection has been a considerable effort in order to eliminate this effect . In this study, the dynamical behavior of a cantilever beam, with different size of a hole, at different distances from the fixed end-for each case- have been measured, evaluated and compared with that of intact beam. It has been shown that the hole may be considered as a defect in most cases, which leads-in general- to decrease the stiffness, according to its size and place, hence affects the dynamic properties i.e., the natural frequencies and the mode shapes. A simulation process for the modal analysis using ANSYS program(release 12.1) is done in order to compare the results. In addition to that, a theoretical analysis is also done. The experimental results of the intact beam were compared with both the ANSYS program and the theoretical results. They showed an acceptable agreement between the three methods.
Keywords: transverse vibration, fault detection, beam crack, beam defect, beam vibration.