This is a requrement from the vibration spec for analysis of different parts - I am not quite sure of what it is asking us to this is the input into vibration test/analysis for structural components. The input which originally was specified at the level of 017 g2Hz has to be reduced by this amount and this is the bit that is confusing me as I can not work out the relationship of the dB and PSD.
SORRY TO BE SO VAGUE BUT THAT IS THE DEPTH OF MY KNOWLEDGE ON THIS TOPIC: I will on Monday post a more comprehensive description.
The problem I am trying to tackle involves the reduction in the PSD spectrum levels for the operational vibration of components. The current input for the operational vibration calcs is based on the -6db/octave spectrum. It has been requested to use a spectrum reduced by 4.5 db as the input!!.
This is as far as I can understand from the requirements and it does sound vague and I do not quite understand it. I was hoping that someone else can make more sense out of this. can you?