Effect Of Laser Distance Measurement For Fatigue Crack Detection On Aluminium Plate Using Laser Doppler Vibro-Meter

Abstract

Fatigue cracks can occur because the material is unable to withstand the load applied repeatedly. A nonlinear vibroacoustic method was introduced to overcome this problem. This is because this method is one of the best solutions because it is suitable for detecting fatigue cracks which is sensitive enough to detect small cracks. The aim of the research is to determine the effect of laser distance measurements on fatigue crack detection using the vibroacoustic method. The vibroacoustic method is a method based on the propagation of high frequency sound waves in solid structures with low frequency excitation. The trained output signal will be converted from the time domain to the frequency domain which is supported by the use of MATLAB software. The analyzed data shows that measuring the laser distance will influence the crack detection process. Then data obtained from the power spectrum using nonlinear vibroacoustic testing is used to plot the high frequencies of 60, 150, and 200 kHz with the laser measurement range. And the research results show that the 60 kHz frequency is the best choice and is sensitive enough to detect small cracks and is able to detect relatively large cracks well.