Vibration Analysis of Cracked Beam Using Fuzzy Logic Technique

Vibration analysis is helpful in an industrial to relieve maintenance costs. It is often referred as 'Predictive Maintenance'. Structural destructions occur in a beam which is used in bridge or in a rotating machine shaft. To prevent these conditions there should be structural health monitoring. Generally in detection techniques, NDT i.e. non-destructive testing is generally exploited due to inexpensive cost and its operation. Due to crack, stiffness (hardness) of the structure decreases and damping of the structure increases i.e. oscillation increases. A cantilever beam having single crack with crack depth utilized for experimentation. For this determination, the vibrations due to impact hammer were analysed. With the help of FFT using MATLAB, first three natural frequencies were taken to investigate crack depth size and crack location of the beam. Fuzzy logic is easily manipulated and it will generate a better result than predictable control technique. Both modes of FIS i.e. fuzzy inference system, Mamdani FIS and Takagi-Sugeno FIS are related for the calculation of crack depths and crack locations. Mamdani FIS offers realistic outcome than Takagi-Sugeno FIS and it is well suited to human input. Finally the results from MATLAB using fuzzy logic toolbox are authenticated by performing experimental study.