×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Polar Moment of Inertia in NX7

Polar Moment of Inertia in NX7

Polar Moment of Inertia in NX7

(OP)
I am trying to figure out a polar moment of inertia in NX7 of a hollow section. In the Analysis->Section Inertia menu, it states the section type as Hollow and to specify a "Hollow Thickness". I don't understand what this "Hollow Thickness" is referring to. If I change the value, it changes my result.

I am used to the program (Pro/E) solving this for me and not having to specify anything but a cross section. Can anyone help me out? This is what my part looks like. I'm trying to get the polar moment of interia with respect to the left vertical edge, in the x-axis.

RE: Polar Moment of Inertia in NX7

You're misunderstanding the use of the term 'Hollow' for the 'Section Type'. In your example, despite the face that it has an internal 'void', it is is NOT 'Hollow' for purposes of this analysis. Change this setting to 'Solid' and ignore the value for 'Hollow Thickness'.

The 'Hollow' option is for those situations where your profile consists of only curves and you're using the 'Existing Section' type of analysis. This is intended for when the existing 'section' of curves represents the cross-section of a thin-walled body, like a piece of ductwork or other sheetmetal part.

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

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

RE: Polar Moment of Inertia in NX7

(OP)
John,

Thanks for the response. I have tried using the "solid" section type, but it just gives me a warning when I click OK or Apply that says "Due to open sections, hollow analysis is used". Any suggestions?

Thanks

RE: Polar Moment of Inertia in NX7

Without seeing your model I couldn't comment on this since the image that you posted appears to represent the cross section of a SOLID body.

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

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

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources