Identification of Crack Location and Depth in Cracked Beam using Natural Frequencies

Abstract

Cracks in a vibrating structural component reduce safety and can cause catastrophic failure. The discontinuities like cracks and notches change the dynamic behavior of structure. The change in vibration parameters depends upon location and severity of the damage. So it is very important to study the e ect of crack on vibration behavior of structure to achieve structural safety and performance. The detection of damage by using change in vibration parameters may prove a better way in structural health monitoring. In present work, the vibration analysis is performed on isotropic and laminated beam with and without crack by Euler Bernoulli beam theory, nite element method, conventional nite element software(ANSYS) and by experimental method by using FFT analyzer. The results obtained by di erent methods shows close con rmation. The various crack detection algorithms are studied and method to investigate crack location and its depth based on the natural frequencies is adopted. The analysis for crack detection is performed for cantilever and simply supported beam for di erent crack location and crack depth. Natural frequencies of cracked beam are extracted from ANSYS. The method gives unique results for crack location and depth.