topic Re: Table of internal forces results in Robot Structural Analysis Forum

Table of internal forces results

Anonymous — Wed, 08 Feb 2017 12:48:45 GMT

Hello everyone,

I recently started to use Robot without being trained, so my question will surely sound a bit stupid to you all, but still.
When I am done with my models, I want to get tables with the results of the internal forces in the members of my structures.
I have only found tables of forces or stresses at nodes, but most of the time my bending moments are not going to be at nodes, and I don't want to waste time splitting my members when I know this tool must be in there somewhere.

If any of you could help me, I would really appreciate it.

Have a great day!

Re: Table of internal forces results

Rafal.Gaweda — Wed, 08 Feb 2017 12:59:08 GMT

Re: Table of internal forces results

Anonymous — Wed, 08 Feb 2017 13:21:29 GMT

Thank you very much Rafal.

Any idea if this can be made automatic? To avoid doing this procedure whenever I change the members I filter.

Re: Table of internal forces results

Rafal.Gaweda — Wed, 08 Feb 2017 13:35:22 GMT

I am afraid - not.

Re: Table of internal forces results

Anonymous — Wed, 08 Feb 2017 13:39:39 GMT

That's too bad.
It's weird that other simpler programs like Staad or VisualAnalysis do it and not Robot.

Re: Table of internal forces results

Artur.Kosakowski — Wed, 08 Feb 2017 14:30:56 GMT

Do you mean that you want to display results in number of evenly spaced points along elements of a model? Could you attach screen capture from either of these programs so that we could understand what display of results you exactly need?

Re: Table of internal forces results

Anonymous — Wed, 08 Feb 2017 15:01:06 GMT

Basically I just want a table showing the extreme values of internal forces in bars.
Just like the one you get in Results > Forces > Global extremes, but instead of having the nodal forces, I would like to have the forces inside the members, like max moment in a beam even if it isn't at a node but somewhere along its length.

Rafal's solution works, but it isn't very convenient, especially compared to what I used to do with other programs.

This is the kind of table I would get with Staad for instance:

Re: Table of internal forces results

Artur.Kosakowski — Wed, 08 Feb 2017 15:34:28 GMT

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.

Re: Table of internal forces results

Anonymous — Wed, 08 Feb 2017 16:12:22 GMT

Rafal showed me this method too. I don't find it super convenient because I need to redo it when I change the type of bars I filter.
But unless someone finds something else, I guess that will do for the moment.
Thank you.

Re: Table of internal forces results

Artur.Kosakowski — Wed, 08 Feb 2017 16:50:47 GMT

Out of curiosity - my assumption is that the table in STAAD or the other program is done based on search for values in given number of points, isn't it?

If so,you just type number of points in Robot and you don't have to redo the search for internal points but just tell Robot the number of points to run the search for.

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.

Re: Table of internal forces results

Anonymous — Wed, 08 Feb 2017 17:15:51 GMT

I would assume this too.
It seems to be a good alternative if I set enough points to have accurate results.
Thank you very much.

Just to understand the difference, how does the "characteristic points" option work then? As in, which points are selected?

Re: Table of internal forces results

Artur.Kosakowski — Thu, 09 Feb 2017 09:25:37 GMT

The main difference is that for the 'characteristic points' the search is done for divisions done for each calculation element.

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.

Re: Table of internal forces results

Anonymous — Thu, 09 Feb 2017 13:09:51 GMT

If I got it right from the User's guide, Characteristic points divide the members into 50 parts.
So by using N points with N greater than 50, I can be more accurate than when using Characteristic points, plus I don't have the hassle of needing to go back to the Division points window and refresh each time I check new members.
If that's true, then I can be happy.

Re: Table of internal forces results

Artur.Kosakowski — Thu, 09 Feb 2017 13:23:18 GMT

Number of divisions applies to bars as you defined them (e.g. 101 along a bar element that stands for 3 span beam) whereas when you use characteristic points 50 divisions (I think it is 51 actually so that the middle point is included) is for each calculation (finite) element instead (so 50 for each of 3 of them for the same beam).

Anyway for large number of division points (especially if you define bars as 'single spans') you should be happy with divisions points.

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.