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Valued Contributor
mgaafar
Posts: 107
Registered: ‎11-29-2011
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Isolated nodes can not be deleted

1793 Views, 4 Replies
02-27-2012 12:15 PM

I am having a problem here, when verifying the model and stating there are isolating nodes, when I select the nodes and delete them, they are not deleted.

I tried to open the model in repair mode but with no use.

Also I noted when I select the isolated nodes from the verification windows, they are not highlighed on the screen, and even they can not be shown seperatly on separate windows.

and the model seems to have an error if I continue running. Please help.

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Artur.Kosakowski
Posts: 4,833
Registered: ‎12-17-2010

Re: Isolated nodes can not be deleted

02-28-2012 12:46 AM in reply to: mgaafar

Please check the definition of linear releases. It seems that they you released too many d.o.fs which results in instability messages ( made the screen capture that illustrates the situation with a bar analogy - top node pinned connection and bottom node only in plane horizontal displacement restrained).

 

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Artur Kosakowski
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Valued Contributor
mgaafar
Posts: 107
Registered: ‎11-29-2011

Re: Isolated nodes can not be deleted

03-01-2012 12:53 PM in reply to: mgaafar

Thanks for the clarification, but I actually want to have the wall supported on the ends only and act as deep beam without intermediate support.

So the question again, why there are isolated nodes in the model that can not be viewed or deleted from the model?

Another question please, I tried to delete all other floors except typical precast floor, and I deleted all the linear releases of the panels and I am getting weird results as attached. Panel cut A1 bending moment is reversed!! and the bending moment values are very small!!

Also I tried to delete all the linear releases from the definition box but some of them can not be deleted so I am assuming they are being used in the model but I can not find them, when I show the linear release nothing appears!!?

Please help!

Thanks

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Product Support
Artur.Kosakowski
Posts: 4,833
Registered: ‎12-17-2010

Re: Isolated nodes can not be deleted

03-02-2012 12:56 AM in reply to: mgaafar

Thanks for the clarification, but I actually want to have the wall supported on the ends only and act as deep beam without intermediate support.

So the question again, why there are isolated nodes in the model that can not be viewed or deleted from the model?

 

Linear releases are generated by means of DSC elements which means that additional calculation nodes are created to model the boundary conditions applied to a panel edge. The assumption is that both the 'standard' nodes generated during meshing and the calculation ones have something to be 'attached' to which are the panel you applied the linear releases to and the neighboring one. If there is no neighboring one or all d.o.fs are released this is no longer true and each model generation will created these isolated nodes again. You can either ignore them or model the shear walls in the alternative way e,g, in the way shown on the attached picture.

 

Another question please, I tried to delete all other floors except typical precast floor, and I deleted all the linear releases of the panels and I am getting weird results as attached. Panel cut A1 bending moment is reversed!! and the bending moment values are very small!!

 

I recommend to check the deformation first. As you can see in these locations the structure moves upwards. The reason is that surface load applied to the panel is in fact according to your decision transferred to the walls rather than applied to the floor. The deformation of the floor in such case is just the function of the deformation of the whole structure. Perhaps you should use orthotropic definition of panel thickness rather than use the  triangular and trapezoidal load distribution.

 

Also I tried to delete all the linear releases from the definition box but some of them can not be deleted so I am assuming they are being used in the model but I can not find them, when I show the linear release nothing appears!!?

 

They are 'kept' as a part of rtd file rather than model. If you e.g. copy the entire model to clipboard and paste it to a new project you will be able to delete them from the dialog.



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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Valued Contributor
mgaafar
Posts: 107
Registered: ‎11-29-2011

Re: Isolated nodes can not be deleted

03-02-2012 01:40 PM in reply to: mgaafar

Thanks very much for the clarification, I did not know that going to one-way slab option will basically ignore the slab analysis and focus on the support in getting the loads to the support.

but that is good to know, thank you very much for your help.

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