FAST FOURIER TRANSFORM <FFT> 

 38X UALUES - 59 



TAPE 



• 9 FILE • 38 



HYD1/'2:H2 L4 



PEAK 





AMPLITUDE 



FREQUENCY 



8.118 U 



38 Hz 



8.861 U 



88 Hz 



8.848 U 



128 Hz 



8.848 U 



168 Hz 



8.872 U 



288 Hz 



8.842 U 



298 Hz 



8.188 U 



438 Hz 



8.891 U 



598 Hz 



8.896 U 



638 Hz 



8.887 U 



698 Hz 



8.81 8.14 8.27 8.39 8.52 8.65 8.78 8.98 1.83 1.16 1.29 



1888 Hz 256 p/w 



(a) Damaged region. 



FAST FOURIER TRANSFORM <FFT) 

 38* UALUES - 5 



TAPE • 9 FILE ft S3 

 HYD1/2:H13 L15 



PEAK 

 AMPLITUDE FREQUENCY 



8.344 U 



438 Hz 



(b) Solid region. 



Figure 24. Frequency spectrum: damaged versus solid region of standard 

 test pile. 



42 



