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Effective mass of the frequency analysis shows more than the model mass 1

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kumara123

Geotechnical
Jun 13, 2016
26
Hi,
I ran a frequency analysis in Abaqus to find the first natural frequency and frequency related 95% model mass. The obtained participation factors are very much low and also effective mass (e.g - 6.74E9) for the rotation components are larger than the total mass of the model (4.27E7). Can anyone explain this to me, please? the .dat file is attached here.
Thank you.
 
 http://files.engineering.com/getfile.aspx?folder=4e616fdd-f8e8-4a41-b1c3-d5871dd9fb9f&file=Job4-4.dat
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I think the rotational components can be ignored. They are highly dependent on the location of the part and have no real meaning.
 
Hi, Thanks for your reply. I 'll ignore that part. But I have a problem with obtaining frequency related to 95% model mass.
I extracted 30 modes and participation factors are added together, the values are very low (e.g. 1.5, 2.3 and 2.0 for three components). Should I want to extract more modes (until I get the summation of 95) to find model mass related with 95% model mass? please find the attachment of the participation factors.

Thank You
 
 http://files.engineering.com/getfile.aspx?folder=1ee32e63-4937-4a6e-8d2e-35f598f1cf32&file=Capture.PNG
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