topic Re: Structural Shape columns in Inventor Forum

Structural Shape columns

Cadkunde.nl — Fri, 09 Feb 2018 12:21:05 GMT

When looking at a content center family in the structural shapes, you get a very very large table with many columns for:

- Section Area

- Specific Mass

- Moment of inertia

- Section Modulus

- Radius of Gyration

- Torsional Rigidity Moment

- ETC ETC ETC ETC ETC ETC and a lot more ETC

Are these columns actually used by anything anywhere in Inventor?

When I have to add a size that is not already in the content center, I try to complete these columns too.

Inventor warns me even when I do not.

But after preparing the content center for many companies, I start to wonder, why the hell am I doing that.

Are these columns actually used? Or are these columns just fillers to look complete?

Re: Structural Shape columns

Mark.Lancaster — Fri, 09 Feb 2018 12:43:12 GMT

@Cadkunde.nl

These columns are needed for FEA on the frame and for advanced engineering information. At my last company when we did this, we only provided the ones that are needed and all of the other ones was left empty. We never did any FEA or in-depth study of the structure.

Re: Structural Shape columns

Cadkunde.nl — Fri, 09 Feb 2018 12:56:41 GMT

But is it linked to FEA? or just to complete all information?

Because this information can also be found at suppliers of these structural shapes if ever needed in a far future.

If it is not linked, I don't have to put any effort/time in it, and its quite time consuming

Re: Structural Shape columns

Mark.Lancaster — Fri, 09 Feb 2018 13:01:49 GMT

@Cadkunde.nl

Inventor FEA reads this information from the model. As far as I know its not going to prompt you for the information. Yes it can be found in structural engineering books and/or from the vendor. But that doesn't mean Inventor FEA is going to stop and ask for it.

Update: Anyhow I will tag @TheCADWhisperer for his input on the FEA/structural information.

Re: Structural Shape columns

Cadkunde.nl — Fri, 09 Feb 2018 13:23:04 GMT

Yes, I really want to be certain if this data is actually being used. If FEA uses it, I must make it complete.

AFAIK content center defines model geometry and the material library defines material properties such as density.

FEA uses Geometry + material properties to calculate section area, specific mass, sectional modulus, torional rigidity, etc.

This makes me guess that all these fields are just for show, and then: why spend hours on filling that info, that no engineer will view.

Can anyone confirm?

Re: Structural Shape columns

TheCADWhisperer — Fri, 09 Feb 2018 13:44:50 GMT

@Cadkunde.nl wrote:

....Are these columns actually used by anything anywhere in Inventor?

There are three environments for analysis in Inventor.

The first two, the Beam/Column Calculator and Frame Analysis use simple beam elements and require that information.

Beam/Column Calculator doesn't require any actual modeled geometry and is limited to a single beam.

Each beam element is only one element with a node at each end.

The Frame Analysis works with only straight Frame Generator components.

Neither of these analyze curved beams.

The Stress Analysis uses mesh elements rather than beam elements and does not require the section information (but the material properties is required - mass density, modulus of elasticity and yield stress - but these properties are not in the beam definition).

But Stress Analysis with mesh elements can be impractical for frames of even medium complexity because of the large tetrahedral matrix of elements and nodes.

Bottom line, if you aren't doing beam element analysis - you don't really need those parameters.

Re: Structural Shape columns

Cadkunde.nl — Fri, 09 Feb 2018 13:41:24 GMT

Thanks for this fast and complete information. Also thanks Mark Lancaster for forwarding.

Re: Structural Shape columns

mikegreslick6607 — Fri, 09 Feb 2018 14:12:07 GMT

Edit: I see that someone else responded before me 😞

A great deal of that information is most definitely used in a Frame Analysis when frames are made in the frame generator. In it's simplest terms, Frame Analysis is really just FEA with beam elements, where of course, this information is critical.

Here's a small example of just some of it: