moments of inertia - defined with respect to?

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Nur Adila Faruk Senan
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Joined: Tue Apr 06, 2010 8:20 pm

moments of inertia - defined with respect to?

Post by Nur Adila Faruk Senan » Mon Apr 04, 2011 4:18 pm

Hi,
Are the moments of inertia defined with respect to the center of mass, or the body's frame of reference? I.e., if the body's frame is at P_o and the CM position is located at x_CM from P_o, is the inertia specified with respect to the body's center of mass, or with respect to the body's frame?

http://wiki.simtk.org/opensim/FrontPage ... Frames.jpg

Thanks!
adila

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Ayman Habib
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RE: moments of inertia - defined with respect to?

Post by Ayman Habib » Wed Apr 06, 2011 10:47 am

Hi Adila,

The moments of inertia are defined wrt the center of mass rather than the geometry origin.

Best regards,
-Ayman

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Nur Adila Faruk Senan
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RE: moments of inertia - defined with respect to?

Post by Nur Adila Faruk Senan » Wed Apr 06, 2011 1:55 pm

Hi Ayman,
Got it - thanks!
adila

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Marco Senteler
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Re: moments of inertia - defined with respect to?

Post by Marco Senteler » Sun Sep 25, 2011 6:59 am

Hi Ayman,
I've got a related question: in which coordinate system (i.e. axis orientation) are the inertial properties defined? global axis or body specific axis? (important when body-coordinate system is oriented differently)
Thank You!
Marco

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