Random Vibration Calculations

[scotland6]

I have a stepped random vibration PSD profile going from 20Hz to 2000Hz (4.2 grms). I have a suspended mass of about 5kg on 4 off AV mounts. Can anyone give me an idea of how to select the mounts or caclulate the response given that the frequency of the suspended mass has to be approx. 40Hz?
I am interested in the transmisibility and the displacement of the mass under this random vibration over this frequency range. Can I calculate the suspended mass output PSD given the above input? Also how do I calculate equivalent sine response?
I have designed for 1/2 sine shock pulse but I am unsure of random.
Any help would be appreciated.

Regards

Scotland6

 

[zzy]

Yes. It is possible to calculate ramdom response based on your structural parameters and input PSD chart with SOFTWARE. As an output, you will get responses (displacement, velocity, or acceleration) in terms of PSD (response v.s. frequency^2) or RMS.
The procedure involving both theories on vibration and statistics. Therefore, it is much more complicated than deterministic system's vibration. It is hard to explain here in limited space.
If you need any assistance, I can spend some time helping you go through in detail. If you want to, please contact me at zzyang0516@yahoo.com