Evaluate the FRF in terms of Amplitude and Phase

Hello,

I have this question and I am not really sure how to approach this?

1. A beam structure is excited with a band-limited random signal in the frequency range [5 − 90] Hz and the data are recorded in the “beam-experiment.mat” file. The sampling rate is fs = 256 [Hz] and the time length is 20 [s]. Evaluate the FRF in terms of amplitude and phase and also in terms of real and imaginary parts.
2. Aliasing Would you suggest a “re-sampling” of the data? In case, which sampling rate would you use?
3. Leakage Would you apply a window function to the time signals? In case, which one would you use? Are there any benefits in using the “zero-padding” technique?
4. Which is the best FRF estimator, according to your opinion and expertise? How many “segments” have you considered to properly evaluate the spectral density functions? Which is the “overlap”? How does the coherence function look like?