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aleksander.marek
Posts: 7
Registered: ‎01-31-2012
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RC BEAMS - Problem with combination

1244 Views, 5 Replies
11-10-2012 11:35 AM

Hi,

 

First of all I'd like to point out that I'm new to robot. I am supposed to design RC Frame for my classes, thus I wanted to learn Robot during this task. I managed to create whole model and load definitions, together with combinations. Now, what I understood reading this forum, I should check which automatic combinations create maximum forces and produce them manually as Manual Combination, then when I export model to RC Design I should select Manual Combinations and check created combination... I did that and still envelopes in design model bases on simple cases (I guess). What should I do? Is there any method to set Robot to use maximal/minimal envelope forces in RC Design Module? Or only producing many manual combination? 

I am working on Robot 2012 Educational Version, and polish codes (old ones) for RC and combinations. 

 

PS. I attach my file to this post

PS.2 If you try to open my file could you check if ROBOT crashes in RC Design module when working on roof beam?

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Artur.Kosakowski
Posts: 4,777
Registered: ‎12-17-2010

Re: Problem with combination

11-12-2012 12:10 AM in reply to: aleksander.marek

You have two options:

1. Import simple load cases. In such case Robot will create combinations automatically inside the RC design modules

2. Import manual combinations you created in the model. In such case only these combinations are used for the design.

 

The RC Column and RC Spread Footing modules do not use the envelope of results - they check each of the combination one by one regardless of the way they are created

The RC beam module can either use the envelope of results of combinations (simple bending) or run the design for each combination one by one (e.g. tension/compression +  bending)

 

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.

 

 



Artur Kosakowski
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Active Member
aleksander.marek
Posts: 7
Registered: ‎01-31-2012

From what I saw, he makes combinations inside RC module,...

11-12-2012 07:00 AM in reply to: Artur.Kosakowski

From what I saw, he makes combinations inside RC module, for loads applied only on beam stand-alone, so if wind doesn't have impact, is it right? Automatic Combinations says that moment over support is ~1960 kNm, while RC module shows < 1400 kNm, which is big difference...

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Artur.Kosakowski
Posts: 4,777
Registered: ‎12-17-2010

Re: From what I saw, he makes combinations inside RC module,...

11-12-2012 07:59 AM in reply to: aleksander.marek

As I'm not sure which loads you actually imported I decided to delete the beam from the RC Inspector and import it again selecting all simple load cases. Then I compared the results from the model (30 cm from the bar end where there is the edge of the support  and the value in the RC Beam design module). All load cases defined in the model have got their influence as imported are internal forces rather than loads.



Artur Kosakowski
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Active Member
aleksander.marek
Posts: 7
Registered: ‎01-31-2012

Re: From what I saw, he makes combinations inside RC module,...

11-12-2012 08:48 AM in reply to: Artur.Kosakowski

Ok, I see your point, program takes to calculations maximal force at edge of support rather than maximal force over support (in idealised model). Now you cleared my mind, thanks for help

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Artur.Kosakowski
Posts: 4,777
Registered: ‎12-17-2010

Re: From what I saw, he makes combinations inside RC module,...

11-12-2012 11:56 PM in reply to: aleksander.marek

support type.PNGThis depends on the selected support type.

 

 



Artur Kosakowski
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