When a crack is present in a structure then the probability of failure of that structure is higher. Failure occurs when the natural frequency of the periodic force and the natural frequency of the structure are in a state of superposition. To avoid this phenomenon it is essential to determine the natural frequency. The purpose of this book is to analyze the behavior of natural frequency for various parameters such as crack position, crack depth, crack opening and mesh sensitivity. In this study, the first five modes of vibration of both cracked and uncracked I beam has been shown. Further analysis of resonance for a fixed vertical load has also been shown. A combination of Hexahedral and wedge elements has been used for the analysis of the cracked structure. As problems regarding discontinuity are very difficult to solve analytically, hence one of the most popular finite element analysis software 'Abaqus CAE' was used for the analysis of the cracked structure. The findings of this book are that the presence of crack reduces the natural frequency of the beam, The reduction is related to the position of the crack, it's opening and it's depth.