mass moment of inertia

[NikonF6]

How in NX 7.5 I can get mass moment of inertia about an axis away from the body center of gravity.

Thanks

 

[cowski]

When you perform a "measure body" command, the information window will list results:
Moments of inertia (Centroidal)
Moments of inertia (WCS)

The one marked "WCS" is the moment of inertia with respect to the axes of the WCS. So all you need to do is position and orient the WCS as desired before using "measure body".

www.nxjournaling.com

 

[JohnRBaker]

Just move the WCS (not the CSYS) to where you want your axis to be, and then run Analysis -> Measure Bodies and read the results for 'Moment of Inertia (WCS)'.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Digital Factory
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.

 

[NikonF6]

Thanks
Which one is Polar Mass Moment of Inertia? Some strange terminology is there...

Thanks

 

[JohnRBaker]

You will need to derive that from the Mass Moments of Interia. Simply orient the Z axis of the WCS so that it aligns with the polar axis of interest, perform a Measure Body and then ADD the values for Ix and Iy to get the Polar Moment of Inertia about Iz.

https://en.wikipedia.org/wiki/Polar_moment_of_inertia

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Digital Factory
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.

 

[NikonF6]

John and Cowski,
you guys helped me so many times, but I can't do more than thank you.