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At verification/analysis I get messages that there are isolated nodes. I am new to Robot and am finding it hard to detect and remove these nodes. When I click the warning they dont show on the screen and furthermore are not selected so that I can delete them.
How can I get rid of them and proceed with my work.
In some locations of the model you have bar elements intersecting panels very close (but not exactly) to the panel's edges. At such 'apparent' intersections Robot creates calculation nodes but as these these 'intersections' among bar and pale edges are at the limit of the model generation precision these nodes are not 'assigned' to the bar elements (the bar elements are not divided into calculation elements) which results in the isolated nodes warning. It is safe to ignore them but I asked my colleagues from the development team to check if this process can be improved meaning that there is no calculation node generation if the distance to the edge is larger than given limit or the generated calculation node divides the bar too if it is smaller. I'm attachin the model with changed meshes.
Also I see that at the linear supports many pointsupports are now generated. I suppose this is Robot's way to model the line support -
The linear support definition generated nodal supports in all nodes existing along the supported edge.
but at the same time really dont know if Robot just automatically assigns pinned supports to all orphan nodes??
No, it doesn't.
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Artur Kosakowski
Thanks. So I understand that these isolated nodes are generated by Robot itself due to impresicions in my model. I would prefer to get rid of all such instances like to one you showed above by dragging the members to be exactly on edges and intersections. I have tried to do so in the enclosed model - but i still get this messages concerning incoherent edges when I run the analysis.
You need to set iterative adjustments of meshes in Job Preferences, set 'reasonable' sizes of elements of meshes and you may want to correct some definitions of panels' contours.
I suppose these military green signatures indicate some problems with meshing impresisions in the model - but I simply can not see what should be wrong.
I'm not sure what you mean. Could you indicate them on a screen capture using the model I'm attaching please?
On node 120 there is a signature which I do not understand. What is it ?
I assume you refer to the apparently accidental definition of linear support on part of the panel edge. I have deleted it and in addition I have corrected the contour of panel 130.
Is there no way of cleaning out in all of this and make all elements which are very close to merge to each other automatically. For the sake of the structural analysis it does not matter if nodes here and there are moved a centimeter or two.
There is. The detailed correction of the selected objects (e.g. end nodes of a bar) to the indicated plane.
I dont know if I am allowed to raise other questions within the same thread, but there are also these messages regarding stories which I do not know what to do with. I have tried several times to click them manually in to the stories where I think they belong but then I get error messages that they extend out of the limitations of the story. This must obviously happen in a building like this where the sloped roof extends below some of the other stories. This prevents me from getting my model up and running so that i can move on with load application. The tragic thing is that I as far as I understand this whole thing with stories has to do with seismic analysis - which is not needed for this building at all. WHat should I do? can I just turn it of in some settings?
You should set the story assignment as automatic - this will assign surface elements which are defined for a wall that runs through several stories to the right ones.
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
You need to set iterative adjustments of meshes in Job Preferences, set 'reasonable' sizes of elements of meshes and you may want to correct some definitions of panels' contours.
Okay. But I see that you set it to "coarse" which is the same as I had kept it to. So there is no change to what I had done. You must have done something else to the model you sent back because when I run the analysis in your model there are no messages concerning incoherent edges. What did you do? I need to learn this.
set 'reasonable' sizes of elements of meshes - this can be also defined for selected panels in the way shown below:
I suppose these military green signatures indicate some problems with meshing impresisions in the model - but I simply can not see what should be wrong.
These signatures do not occur when running analysis in the model you have repaired and sent back. But it the model I sent you last time they were occuring in panels 149 and 145 and looked like what is shown in the attached PNG image.
There is. The detailed correction of the selected objects (e.g. end nodes of a bar) to the indicated plane.
I understand, but this is what I have been doing, I just havent gotten around to all problems yet. This method is still a one by one method and not and overall treatment in one go like when you ask the model to merge all nodes closer that say 10mm. It would be useful also to merge nodes to planes which they are in close proximity to.
The options of merging (real) nodes but this is a different situation. Here you have a calculation node created at the intersection of a panel edge and a bar element that is not in the panel plane. What should not happen is the situation when such node is created and then not assigned to the bar element. This is caused some inaccuracy of the position of the bar with respect to the panel and we will try to improve this operation to avoid such situations in the future meaning that if elements are within the range of the model generation precision the generated calculated node belongs to the bar and when these objects (panel edge and bar) are separated by a distance that is larger than the model generation tolerance such calculation node is not created. On the other hand mind that in this case you want to move the bar in the direction that is perpendicular to the discussed panel so despite the option you mentioned (adjusting to planes indicated by structural axes or defined by objects such as selected panels) exist they cannot be used automatically to solve this kid of issue.
I assume you mean ticking of "Define graphically" under Geometry/Stories/Stories like what has been done in the model you sent back. But this model still gives warnings that there are elements not assigned to any story.
This is correct as you defined panels (walls) that run through more than one story. In such case you don't want to assign the to a particular story but you can have surface elements (parts of meshes) generated within the ranges of each stories to be assigned to them instead.
Infact most all for the shearwalls in the groundfloor are not assigned to any floor. How does one remove this problem and get these warnings to go away. I tried to do this manually before posting the question above but then I just get these other messages that the elements are outside the limits of the stories.1
As explained above the what is important is the assignment of surface elements. Otherwise define panels one above another within the limkits of a single story.
When running the model you sent back I still get error messages concerning isolated nodes. Why is it that it does not indicate on the screen where the isolated nodes are nor print a log with the numbers of the isolated nodes. One can sit for ever trying to guess where they are. I guess that it is node 70 and 73, but I really dont know. It is hard in this model - and this is only a small model.
When I proceed regardless of the isolated nodes, I am first informed of node 73 which is sligthly of the corner of a panels which I can easily drag in place. But then it proceed to inform me of instability(type 1) in node 70. When I look at it more closely the obvious reason is that it has not been connected to the mesh in the wall. I have tried moving node 70 into the plan of panel 130 by extending, intersection and cut member by plan and to me it appears that the node is within the plan. Why then does Robot not include this node in the mesh. Is there a way to manually edit the mesh at this particular point so that node 70 is included in the mesh.
How would you repair these two instable nodes?
I can't see any isolated nodes reported. Do you mean instability warnings?
Artur Kosakowski
When I run the model which you sent back it informs me of the following 5 instable nodes 70, 73, 101, 120 and 122. In the enclosed model I have solved all except 70. Ticking of the kinematic constraints does not help.
The kinematic constrains are intended for coherence of results in locations of incoherent meshes.
1) How does one force the program to include node 70 in the mesh for panel 130 – see enclosed screendump. For all I can see the node is in the plane of panel 130. Should I have divided the panel at level 5.7?
You need to have it in its plane.
2) What is the governing principle for when an intersecting bar is included in the mesh of a panel. On the enclosed screenshot you can see that the mesh of panel 148 connects to bar 84 while the mesh of the adjacent panel 147 does not connect to bar 84 see enclosed screendump. Actually I would not want it to connect in either case. How does one prevent the program from connecting the mesh of a panel to an intersecting bar?
In your case it is the characteristic point of the panel contour that happens to be in the location of bar intersection with the panel which cause mesh snapping to this point.
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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