Faults detection by finite element analysis of a multi cracked beam using vibration signatures

摘要

In this paper, analysis for fault identification in a cracked beam has been carried out. Theoretical, finite element and experimental analyses for identification of the crack depths and their positions in a beam containing multiple transverse cracks are carried out. It has been established that a crack in a beam has an important effect on its dynamic behaviour. The strain energy density function is used to evaluate the additional flexibility produced due to the presence of crack. Based on the flexibility, a new stiffness matrix is deduced and subsequently that is used to calculate the natural frequencies and mode shapes of the cracked beam. The analysis of the crack structure is done using theoretical, finite element and experimental analysis. The results from finite element method and experimental method are compared with the results from the numerical analysis for validation. The results are found to be in good agreement.