How to get the Second moment of Inertia of a shape in NX
How to get the Second moment of Inertia of a shape in NX
(OP)
I have two shapes that are not exactly easy to Get the I value for.
One is like a tent shape, 5mm thick. Triangular/ hinge at the top with two flanges on either side. In the middle of the tent there is an open rib or web to give the tent more rigidity and stiffner.
I have tried the analyis body function and get a page full of results and section tool also. The Analysis tool Give loads of info. The section tool I cant seem to get it to work.
Anyhow do I pick the right value from the Information list on NX. Its the centroid one right?
I know AutoDesk do it and its pretty clear when its done.
I have another one thats like an S shape extrusion to do also.
One is like a tent shape, 5mm thick. Triangular/ hinge at the top with two flanges on either side. In the middle of the tent there is an open rib or web to give the tent more rigidity and stiffner.
I have tried the analyis body function and get a page full of results and section tool also. The Analysis tool Give loads of info. The section tool I cant seem to get it to work.
Anyhow do I pick the right value from the Information list on NX. Its the centroid one right?
I know AutoDesk do it and its pretty clear when its done.
I have another one thats like an S shape extrusion to do also.





RE: How to get the Second moment of Inertia of a shape in NX
First, create a set of section curves with Insert > Curve from Bodies > Section, then use Analysis > Section Inertia...
Is that what you're looking for?
Cheers,
Jon
JHTH
NX 7.0.1.7 + TC 2007
RE: How to get the Second moment of Inertia of a shape in NX
What goal do you have in mind?
RE: How to get the Second moment of Inertia of a shape in NX
The Information button presents alot and I dont know which is which the way its labeled.
I am after I for calculating deflections
RE: How to get the Second moment of Inertia of a shape in NX
Note that in either case, all you need is a simple 2D profile of you 'beam'.
So if you looking for MAXIMUM Moment of Inertia, go to...
Analysis -> Section Inertia...
...use Type 'Existing Section' and pick the profile of your 'beam' and if all you want if the 'Second Principle Moments' only toggle ON that option. After you select the profile but before you hit OK, toggle ON the 'Show Information Window' option as this will give you the best explanation of the results. There is also a nice option if you're interested in it and that's that you can have the system create for you the equivalent rectangular section which has the same area properties which can be handy if you're looking to simplify you model for analysis purposes.
As for the older function, with a misleading name of...
Analysis -> Advanced Masse Properties -> Area using Curves...
...which has the very old interface but it still works and it will provide Area Moment information both in terms of the Maximum values, but also with respect to the WCS.
Anyway, take a look and see if this gives you what you're looking for.
John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
http://www.siemens.com/plm
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To an Engineer, the glass is twice as big as it needs to be.