Discussion Groups

Robot Structural Analysis

Reply
Distinguished Contributor
refaat
Posts: 121
Registered: ‎09-17-2012

Vertical Panels

444 Views, 13 Replies
01-13-2013 10:58 PM

Dear Colleagues

 

I faced a probem in the shear walls which I have chosen from the middle core of the building . As you see in the capture (1&2) , when I use “ analytical method “ sometimes a message appears saying that  there is (unknow error for the panel) and the reinforcement appears to be not logical as appear in the capture (1) .

This case meet  me in many vertical panels(walls) in the attached model.

 

Could you help me to overcome this problem ?

 

 

http://www.2shared.com/file/5yTRJtF4/Vertical_Panels.html

 

 

Note : If you send  a captures for explanation , Kindly send it as attached.

 

Thanks  in advance

 

Refaat

 

 

Please use plain text.
Product Support
Artur.Kosakowski
Posts: 4,544
Registered: ‎12-17-2010

Re: Vertical Panels

01-14-2013 04:20 AM in reply to: refaat

As far as I can see the area of reinforcement cannot be calculated in one node of the panel. I think that you can use the results from the neighboring elements instead. The values of Ax(-) and Ax(+) are 0s therefore the map will not be displayed. In case you have the problem with other maps make sure the range of the scale is defined correctly.

 

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
Please use plain text.
Distinguished Contributor
refaat
Posts: 121
Registered: ‎09-17-2012

Re: Vertical Panels

01-15-2013 01:20 AM in reply to: Artur.Kosakowski

Dear Artur

 

- Thanks , but I would like to know , what are the main causes for such type of messages "unknown error for the panel ".

 

-   And how I can avoid in  other  models?

 

 That is because I will not be able to submit my calculation report with such errors.

 

With Regards

Refaat

 

 

Please use plain text.
Product Support
Artur.Kosakowski
Posts: 4,544
Registered: ‎12-17-2010

Re: Vertical Panels

01-15-2013 04:26 AM in reply to: refaat

 

- Thanks , but I would like to know , what are the main causes for such type of messages "unknown error for the panel ".

 

The reinforcement calculations is based on the iterative process. In the situations when for some reason this iterative process fails to converge this message is displayed.

 

-   And how I can avoid in  other  models?

 

If this happens you may try to change meshing of the panel. If this fails all you can do is to report such situation and we have to investigate what actually caused the reinforcement calculation process to fail.

 

 That is because I will not be able to submit my calculation report with such errors.

 

I think this should be possible. Having the results in all but one verification points (all centers of surface elements and all nodes but one) it is possible to estimate the value in the missing node from the neighboring results. As far as I can see it is also possible to display maps providing one enters the reasonable values of max and min values on the scale.

 


 

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
Please use plain text.
Distinguished Contributor
refaat
Posts: 121
Registered: ‎09-17-2012

Re: Vertical Panels

01-17-2013 01:12 AM in reply to: Artur.Kosakowski

Dear Artur

 

After I investigated the case by changing  the mesh (size -type)  , I have noted that only in  one situation the message ( Unknown error for panel ) is disappeared when I calculated the required reinforcement without included (ACC) cases.

 

 

Also, I have noted that when I included  (ACC) but calculating the panel using one of the simplified method instead of analytical method, also the message is disappeared, but of course we can't use it in shear walls.

 

Based on above I can say that there is something to calculate the membrane forces during the seismic cases because even when I changed the used code (IBC2000&IBC2006&IBC2009 and UBC97) it gave the same scenario.

 

Note : Kindly take a look to the attached captures.

 

What can I do? , I am really worried from this problem .

 

Thanks for any assistance 

 

Refaat

 

Please use plain text.
Product Support
Artur.Kosakowski
Posts: 4,544
Registered: ‎12-17-2010

Re: Vertical Panels

01-17-2013 01:57 AM in reply to: refaat

As I wrote previously check the values in nodes and centers of these elements in the reinforcement table. Most likely only one of them is missing which influences the display of maps but this should allow you for the estimation of reinforcement areas in these locations. As far as I can tell this situation happens in regions that require low reinforcement. In addition you can try to select these elements and refine mesh in these locations.

 

mesh refinement.PNG

 

You can also try to use the Wood and Armer method.

 

Please mind that you should not use the globally averaged forces for panels with join with other panels that are not in the same plane (wall and slab).

 

 



Artur Kosakowski
Please use plain text.
Distinguished Contributor
refaat
Posts: 121
Registered: ‎09-17-2012

Re: Vertical Panels

01-17-2013 02:25 AM in reply to: Artur.Kosakowski

Dear Artur

 

Thanks for your fast response .

 

-Do you mean (Wood and Armer method) , Can be used for shear walls. As far as I know that it is not considered the membrane forces in shell element ? Pleases , confirm.

 

- Is it correct ?" I used (globally averaged forces)  for two panels(walls) (both vertical) but the angle between them (90 Degree )".

 

- Kindly , could you send me the capture in your previous post as attached ? because I couldn't open it.

 

Thank you very much

 

Refaat

Please use plain text.
Product Support
Artur.Kosakowski
Posts: 4,544
Registered: ‎12-17-2010

Re: Vertical Panels

01-17-2013 03:14 AM in reply to: refaat

refaat wrote:

Dear Artur

 

Thanks for your fast response .

 

-Do you mean (Wood and Armer method) , Can be used for shear walls. As far as I know that it is not considered the membrane forces in shell element ? Pleases , confirm.

 

It does not include Nxx (so indeed if these forces are large than it is better to use the analitical one) but includes Nxx and Nyy.

 

- Is it correct ?" I used (globally averaged forces)  for two panels(walls) (both vertical) but the angle between them (90 Degree )".

 

If you have any not vertical panel at the top or bottom edge of the wall (panel) then you should not use this option.

 

- Kindly , could you send me the capture in your previous post as attached ? because I couldn't open it.

 

Attached.

 


 



Artur Kosakowski
Please use plain text.
Distinguished Contributor
refaat
Posts: 121
Registered: ‎09-17-2012

Re: Vertical Panels

01-17-2013 07:02 AM in reply to: Artur.Kosakowski

Dear Artur

 

Please , take a look to  the attached capture which shows high values(Nxx& Nyy ) at the nodes where ROBOT can't calculate the required reinforcement compared with the other elements.

 

What is your comment about these results ?

 

Note : if you use any capture for explanation . Kindly , send it as attached.

 

Thanks for your cooperation

 

Refaat

Please use plain text.
Product Support
Artur.Kosakowski
Posts: 4,544
Registered: ‎12-17-2010

Re: Vertical Panels

01-18-2013 03:19 AM in reply to: refaat

I think that the results in tee corners are influenced by the fact that this is very 'rigid' part due to sizes of the beams. Actually it seems that you may say that in reality there is no wall in these locations but beams instead.

 

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
Please use plain text.