Investigation of the effect of two open cracks on the characteristics roots of a steel cantilever beam

It is well documented that the presence of transverse crack reduces the local stiffness of the beam, which changes the various vibration parameters of the structure. During the service, the size of the crack increases, therefore structure becomes weaker than its earlier situation. The information of the dynamic response is needed to determine the location and depth of the crack in the beam. In this study, two single sided open cracks on a cantilever beam are considered, which in belief occur due to the action fatigue load in service, so it is very essential to study the effect of two open cracks on vibration parameter of a beam like characteristics root. Tests were conducted on cantilever beam for both intact and cracked cases by using FFT Analyzer. ANSYS software is used to validate the experimental results. The location of the two open cracks in relation to each other affects notably the changes in the characteristics root. The effect of the second crack on the characteristics roots is found less when the depth of the second crack is less as well as it is far away from the location of the first crack. It is also found that when the depth of the crack increases, then there is a reduction in the value of characteristics root. (c) 2017 Published by Elsevier Ltd.