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Frequency Response Deflection Magnitude Error

Frequency Response Deflection Magnitude Error

Frequency Response Deflection Magnitude Error

(OP)
Hello,

I am running a basic frequency analysis to find first mode frequency and deflection magnitudes for a vibration table adapter plate. The plate contains a circular hole pattern to mate to the shaker's head and a hole pattern for mounting the UUT. I created fixed constraints along the bottom edge of the shaker head mounting holes, default meshed, and ran a sine sweep. My frequency magnitude is in the ballpark as verified from hand calculations but my resulting deflection magnitudes are huge (20 plus inches for an 18 x 18 in plate)!

A fellow mechanical engineer I work with ran the same simulation on his own PC and obtianed the same exact results. Am I missing a simple software setting somewhere or is this a software issue? I'm coming from a Nastran/ Patran background so while the interface of Simulation is much easier to learn I still am not comforftable with the results I am getting.

Thanks,
Chris  

RE: Frequency Response Deflection Magnitude Error

Displacement in a frequency study doesn't give you real values, it is only meant to show you how it is moving. I can't really remember how/why this is, but I believe this is so in any software and is a principle of modal analysis.

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