Here is everything you want to know about the field of 'Recip Analysis'. Scroll down to see the various aspects of the analysis.
http://www.dynalco.com/article.cfm?hid=3
Regards
You need to mount a 'Frequency Response Function' on Labview. Not the simplest of tasks, I must add.
I did it after spending substantial time at it.
You wish to know what is the transmissibility of vibration at each frequency within a range of interest. Depends on where your engine is going to...
Have you thought of using quadrature picking ?
For say 20 points and 3 modes, it is very practical and you don't need software, just a force hammer and an accel or, two accels.
