Affiliations: [a] Department of Mechanical Engineering, I.T.E.R, Bhubaneswar, Orissa, 751010, India | [b] Department of Mechanical Engineering, N.I.T. Rourkela, Orissa, 769008, India
Abstract: Premature failure of beam structure is observed due to presence of crack. In the current analysis a fuzzy inference system has been developed for detection of crack location and crack depth of a cracked cantilever beam structure. The six input parameters to the fuzzy member ship functions are percentage deviation of first three natural frequencies and first three mode shapes of the cantilever beam. The two output parameters of the fuzzy inference system are relative crack depth and relative crack location. Strain energy release rate at the crack section of the beam has been used for calculating its local stiffnesses. Different boundary conditions for the cracked beam structure are outlined during theoretical analysis for deriving the vibration signatures (mode shapes and natural frequencies). These signatures are subsequently used for deriving the fuzzy rules. Several fuzzy rules are derived and the Fuzzy inference system has been designed accordingly. Experimental setup has been developed for verifying the robustness of the developed fuzzy inference system. The developed fuzzy inference system can predict the location and depth of the crack in a close proximity to the real results.
