I am new to vibration mechanics and signal processing. Recently, I’ve performed an experimental test with an accelerometer mounted on a plate (shaker). The plate vibrates with exact frequencies 10 and 20 Hz. The purpose of the experiment is to extract the acceleration vs. time and FFT diagrams. I have a basic and fundamental question.
What are the differences between applying FFT to acceleration, velocity or displacement diagram of a dynamic system? Does FFT give the same peaks for the three mentioned diagrams so that I assume that the peaks are natural frequencies of the vibrating system (10 and 20 Hz in this problem)?
I would be appreciated if you could help me with these questions.