Load Cases / Envelope

[georgimonew]

Hello!
I created 4 wind load cases and 3 snow load cases. My problem is to create an envelope containing wind cases and another containing snow ones. Is it possible? By doing this I want to reduce the number of combinations generated my Automatic combinations module. My teacher recommended this, too.
I read that robot cant create envelopes. Is it true?
Thanks in advance.

[40ushek]

the goal - reduce the number of combinations generated my automatic combinations module?

[Rafal.Gaweda]

Take a look at:

http://forums.autodesk.com/t5/Autodesk-Robot-Structural/Automatic-Combination/m-p/3386869/highlight/...

http://forums.autodesk.com/t5/Autodesk-Robot-Structural/Group-the-Combination/m-p/3392707/highlight/...

Usefull zip in last post on this page;

http://forums.autodesk.com/t5/Autodesk-Robot-Structural/Select-Case-Component-No-Results/m-p/3390533

or here

http://forums.autodesk.com/t5/Autodesk-Robot-Structural/Editing-load-cases-in-excel-API/td-p/3320573

[georgimonew]

I was told its theoretically right to make a envelope combination - the Eurocode 1 says that. And the goal of course is reducing the number of combinations. It's a simple steel frame I don't need 200 combinations.
I've read the posts you told me but I see the only way is editing the load cases in excel? Grouping the combinations doesn't make a envelope of them, right?  Is there another way?
And if you don't understand me, I want to make a envelope as SAP2000 do it - it has a load combination type - envelope.

[40ushek]

200 is very little. 1 000 000 combines is normal. I use for that special program (I author). I do it for myself.

[Rafal.Gaweda]

And if you don't understand me, I want to make a envelope as SAP2000 do it - it has a load combination type - envelope.

---

I think we do not understand you. Also, at least me, do not know what is envelope case\ combination in SAP.

Envelopes are generated automatically in Robot these ways:

[georgimonew]

I want to create a envelope of 4 wind load cases and combine this envelope in ULS combinations, for example,
G+Q+0.5*envelope (Wind1; Wind2; Wind3; Wind4).
Thanks for the help. 🙂

[Rafal.Gaweda]

I want to create a envelope of 4 wind load cases and combine this envelope in ULS combinations, for example,
G+Q+0.5*envelope (Wind1; Wind2; Wind3; Wind4).

And the result of the above is ...?

Tell me what you want to get. 

[georgimonew]

Tihs is a combination. I want the maximum values of the internal forces. Instead of combining dead and live loads with 4 wind load cases to be just 1. I hope I gave the right answer.

[Rafal.Gaweda]

Tihs is a combination. 

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Not possible.

[40ushek]

combine 1 

Axial = 100; Moment = 14 (Axial MAX)

combine 2

Axial = 14; Moment = 100 (Moment MAX)

combine 3

Axial = 99; Moment = 99( stress MAX)

[qvt]

thannks for your help ?

 but how i can chose combo envelop for design RC ? 

[Rafal.Gaweda]

Go to Combin. tab and select combinations - if I understood you correctly

[Artur.Kosakowski]

Hi @qvt

The design of reinforcement is done for each of the combinations one by one and designed reinforcement is such that it secures element's capacity for all of them. 

Please see: Rc Members - Required Reinforcement - Beams

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.

[leidy.arbelaez]

Pudiste hacerlo? me podrías decir como?

[leidy.arbelaez]

Puedo meter una envolvente dentro de una combinación?

[joaquim.moral]

Hola @leidy.arbelaez,

te animo a que si publicas en español abras un nuevo tema en los foros de la Comunidad Autodesk en Español.

Aquí te dejo el link: https://forums.autodesk.com/t5/espanol/ct-p/157

¡Hasta pronto!