Identification of crack location and intensity in a cracked beam by fuzzy reasoning

In this article, a soft-computing-fuzzy-logic approach for crack identification in cantilever beam has been considered. The fuzzy controller consists of six input parameters and two output parameters. The input parameters are first three relative natural frequencies and first three relative mode shape differences in dimensionless forms. The output parameters are relative crack location and relative crack depth. Theoretical analyses have been done including the effects of crack depths and crack locations on the natural frequencies and mode shapes. Several fuzzy rules are outlined for the fuzzy controller. Gaussian membership functions are used for the fuzzy controller. The local stiffnesses at crack location of the beam have been calculated using strain energy release rate. The fuzzy rules are used to identify the location and depth of the crack. Finally, the effectiveness of the developed fuzzy controller has been verified by the results obtained from the developed experimental set-up.