Suitable signal processing techniques for frequency response functions?
I agree with all of what Dan has said, and would add that the method of excitation is probably not the best for reproducibility. Impulse hammer taps can have different frequency content depending on the location of the strike and the angle of strike, not to mention they are slow as compared to shaker excitation or using a loudspeaker (air coupled). If you're going to be amassing statistics you want to make it quick and reproducible. You can get quick FRF's with a logarithmic chirp excitation in this frequency range, I think.