Node instability

Node instability

Anonymous
Not applicable
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Message 1 of 8

Node instability

Anonymous
Not applicable

This is my first time using Robot--I'm trying to do a basic structural analysis for my Revit project. When I import and run calculations in Robot I get a series of messages:

robot snip 01.PNG

 

and then when I look at my max displacements and deflections they're really wild and all over the place. What should I do to fix this so that I don't get really insane results and can actually use Robot?

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2,308 Views
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Replies (7)
Message 2 of 8

Rafacascudo
Mentor
Mentor

Search forum.look for similar posts.
Click on the error messages and unstable nodes will be highlighted.
Sometimes it is obvious why the node is unstable.Lack of support, too many bar releases, etc.
Instabilities of type 1 and 2 cannot be ignored. Type 3 can be ignored if displacements are coherent with structure size and loads.
If you still cannot solve the problems by yourself, send the model

Rafael Medeiros
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Did your question get successfully answered? Then click on the ACCEPT SOLUTION button.

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Message 3 of 8

Anonymous
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I looked through a variety of related posts and am still not quite certain what's wrong. There are some bars that look to be attached in the Revit analytical model but then aren't in Robot? Here's a link to the .rtd file. 

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Message 4 of 8

Rafal.Gaweda
Autodesk Support
Autodesk Support

Why do not you look at your model , esspecially in nodes reported in warning messages, and correct it first?

It is inaccurate.

 

in1.jpg



Rafal Gaweda
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Message 5 of 8

Anonymous
Not applicable

Because the elements were connected and I can't quite figure out how to move the nodes to connect to the nearby bars of the truss? I've never used Robot before--and I'm trying to just get quick results to make sure my Revit model is relatively accurate.

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Message 6 of 8

Rafal.Gaweda
Autodesk Support
Autodesk Support
Accepted solution

Because the elements were connected

 

I have shown you - they are not connected.

 

and I can't quite figure out how to move the nodes to connect to the nearby bars of the truss? I've never used Robot before--

 

Edit \ Edit \ Move

or

Edit\ Detailed Correct -> to line

 

 

and I'm trying to just get quick results to make sure my Revit model is relatively accurate.

 

Unfortunately your Revit analystical model is not accurate enough.

 



Rafal Gaweda
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Message 7 of 8

Anonymous
Not applicable

Thanks! I've tried to connect all of the members and most of the warning messages have gone away--but I cannot get rid of node instability warning for four nodes even though they look connected. 

nodes instable 01.PNG

 

nodes instable 02.PNG

 

Is there anything I can do to fix this?

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Message 8 of 8

Rafal.Gaweda
Autodesk Support
Autodesk Support
Without the file... too many releases


Rafal Gaweda
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