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Partial Fixity

16 REPLIES 16
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Message 1 of 17
Wioletta_F
1913 Views, 16 Replies

Partial Fixity

Hi,

I've got a question with regard to partial fixity of RC columns. My problem is that I'm trying to analyse an exisitng concrete structure that deflected 'a lot'. I've managed to model the whole structure and have run calculations in 2 options: fully fixed columns - option 1 and pinned - option 2. The long term deflection results from Robot indicate that I should be considering a partial fixity of columns (I should mention that I've got a survey report with deflection that occured in 'real life' ). Could you help me to define 'partial fixity' of columns? I tried defining a new release type by going to new release/ elastic/ partial stiffness coefficient but no matter what value i put when verifying the model I get an error saying 'to excesive release  at the bar'. Please help.

16 REPLIES 16
Message 2 of 17

Please check http://forums.autodesk.com/t5/Robot-Structural-Analysis/Steel-design/m-p/3573540

 

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
Message 3 of 17

Thanks Artur.

This works better now. Unfortunately during the deflection analysis I get an error now: Incoherent results for panel 2, although I did not change anything appart from fixity and other panles are ok (no error message). The error is fallowed by 'execution problem 2520' when I ignored.

 

Message 4 of 17

Am I correct that you selected the stiffness update method? What is the analysis type - linear static or nonlinear ? Do you have enough free space on the disk? Do you run the file from the local derive or a network location? Is it the same for the multi-threaded solver?



Artur Kosakowski
Message 5 of 17

0. Linear analysis

1. Equivalent Stiffness (Elastic) - works, I do get results - although the Error comes up - see the attached pdf

2. Stiffness update stops the analysis and Execution problem comes up - see the pdf

3. Changed the solver - same

4. I think I've got enogh space on the disk

5. I'm using a network license of Robot and running the file from server.

 

 

 

 

 

Message 6 of 17

Try to save the file on a local drive change the reinforcement calculation method from analytical to Wood and Armer - any change? 

 



Artur Kosakowski
Message 7 of 17

Hi

I saved my file on a local drive. First time I run analysis all went ok, after that either the 'incoherent data' or 'execution problems' occur (I tried couple of times).

 

btw. The values of stiffeness coefficients range between: 0.0 (a released direction) and 1.0 (no release). So if i type in 0.1 does it mean 90% of fixity or 10% of fixity. Thanks.

Message 8 of 17


I saved my file on a local drive. First time I run analysis all went ok, after that either the 'incoherent data' or 'execution problems' occur (I tried couple of times).

 

Can you calculate (again) deflections after closing Robot and opening it again?

 

btw. The values of stiffeness coefficients range between: 0.0 (a released direction) and 1.0 (no release). So if i type in 0.1 does it mean 90% of fixity or 10% of fixity. Thanks.

 

10% but you can easily check that making a test on a single bar model with fixed supports at both ends Smiley Happy

 

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
Message 9 of 17

 

 

I even shut the computer down and that did not help much.

 

 

 

I asked about the fixity because I did as you said - changed values couple of times and the deflection results went up and down not exactly as I expected them to go :).

 

 

 

Message 10 of 17

Send me the rtd file and indicate the slab to run deflection verification for please. Thank you.



Artur Kosakowski
Message 11 of 17

When I run the model I get:

 

80mm deflection for stiffeness coefficient factor of 0.05 and 89mm for factor of 0.1.( In reality there is 110mm  - I know it's a lot :-). It seem wrong...

 

Thanks Artur

 

Calculations for panel 7 please

Message 12 of 17

Could you attach the file again with no % in its name as it cannot be downloaded please?



Artur Kosakowski
Message 13 of 17

Sorry about that.

Message 14 of 17

Try to run calculations of reinforcement with the settings on the 1st picture. That should allow you to run verification with no problems.

 

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
Message 15 of 17
Wioletta_F
in reply to: Wioletta_F

Hello Artur. Have you had chence to look at this , please?

 

Message 16 of 17

Have you read the message directly above your question? Smiley Wink



Artur Kosakowski
Message 17 of 17
Wioletta_F
in reply to: Wioletta_F

Thanks Artur, my emails are as slow as traffic today.

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