I would be interested to hear any comments on our attached case study.
Thx.

vert_motorub.ppt (1,042 Kb, 72 downloads)

Pete,
I wonder whether or not vibration data contained any symptoms pointing to a rub, looseness. According to this analysis there was nothing in data except increased amplitude being a matter of concern? If symptoms were in fact missing then why?

Good question. I had not taken a close look at the vib data for previous clues since my main focus was on understanding the failure.

I went back and looked and there was also some increased noise floor that may have been a clue of a mild rub in progress if we were really scrutinizing the spectra closely. Waterfall attached. We don't have twf or other data on these machines.

Here is the same file in pdf format.
Use view/rotate to view in landscape.

vert_motorrub.PDF (1,670 Kb, 14 downloads)