CrackAl,
As you noted, the time scales in those two files are different. The time scale in “Constant Loading Profile-5 cycles.csv” represents the frequency of applied cyclic loading. The time scale in signal-1/signal_2 means the frequency of the ultrasonic signal.
They are not directly correlated. The fatigue loading cycle can be incorporated into a fatigue model, if you want to consider the physics of fatigue failure. Ultrasonic signals are used for extracting features and building machine learning models.