Critical speed and natural frequency analysis of cracked rotor shaft

Critical speed and natural frequency of rotary shaft were obtained experimentally using Fast Fourier Transform. Critical speed varies in the range of 5% to 8.5% due to change in crack depth and crack location. Variation of natural frequency was observed 6% to 12% due to change in crack depth and crack location. Frequency vs. amplitude analysis of rotary shaft carried out using Fast Fourier Transform analyzer.