topic Re: Meshing problem in Robot Structural Analysis Forum

Meshing problem

Anonymous — Thu, 11 Oct 2012 16:24:24 GMT

it seems that no matter what I try (various meshng methods, size etc.) I cannot get a proper mesh for the walls of the attached model.

Moreover If I particularly select one of the walls with meshing issues and then delete its mesh, then I get other walls mesh also deleted... very awkard...

I already spent a lot of time trying to figure it out, so I though sharing this issue here would be helpful.

thanks for any input.

I'm using Robot 2013 under windows XP

Re: Meshing problem

Artur.Kosakowski — Fri, 12 Oct 2012 07:19:39 GMT

I used the repair mode to deal with the meshing issue (please check the Job Preferences settings in the file I'm attaching) and corrected inaccuracies in position of the nodes (e.g. 150 and 68 among others).

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.

Re: Meshing problem

Rafal.Gaweda — Fri, 12 Oct 2012 07:40:08 GMT

Hint: http://screencast.com/t/imIRxs0dl

http://forums.autodesk.com/t5/Autodesk-Robot-Structural/Rounding-up-coordinates-API/m-p/3430533/highlight/true#M4399

Re: Meshing problem

Anonymous — Fri, 12 Oct 2012 10:18:07 GMT

@Artur.Kosakowski wrote:
I used the repair mode to deal with the meshing issue (please check the Job Preferences settings in the file I'm attaching) and corrected inaccuracies in position of the nodes (e.g. 150 and 68 among others).

Thanks!!

Didn't cross my mind that the repair mode would solve it. The help is quite silent about "repair mode" features.

Could you please tell me what exactly the repair mode did?

As far as the nodal positions are concerned, you have to do it manually right? I mean... inspecting each node one by one... which is a tedious task. I guess since this model uses inclined axes any auto rounding up would potentially move some nodes away from adjoining elements. For instance, using the app that Rafal suggested, after rounding up, node 68 is moved away from the supporting beam, leaving the two conccurent braces not connected to the adjacent beam. That's why you did it manually, right?

thanks for your input.

Re: Meshing problem

Anonymous — Fri, 12 Oct 2012 10:25:29 GMT

@Anonymous_Adsk wrote:
Hint: http://screencast.com/t/imIRxs0dl

http://forums.autodesk.com/t5/Autodesk-Robot-Structural/Rounding-up-coordinates-API/m-p/3430533/highlight/true#M4399

thanks!

Very useful, but not for this case...

The rounding up moves away nodes from adjoining elements.

Re: Meshing problem

Artur.Kosakowski — Fri, 12 Oct 2012 10:30:59 GMT

Didn't cross my mind that the repair mode would solve it. The help is quite silent about "repair mode" features.

Could you please tell me what exactly the repair mode did?

Checked and corrected the internal consistence of the model.

As far as the nodal positions are concerned, you have to do it manually right?

Apart from defining them correctly when you are creating the model you can also use the detailed correct option and adjust them to indicated (e.g. skewed) plane. Actually before posting the corrected model I checked the deformations and noticed the problems. Having to deal with only few nodes I moved them manually. Rounding up coordinates for planes that are not parallel to the global coordinate system axes may not solve all the problems but will many of them anyway.

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.

Re: Meshing problem

Rafal.Gaweda — Mon, 15 Oct 2012 10:48:58 GMT

Very useful, but not for this case...

Just to show you the problem.

Correct only Z by this macro, then remesh it

Re: Meshing problem

Anonymous — Mon, 15 Oct 2012 12:11:50 GMT

@Anonymous_Adsk wrote:
Just to show you the problem.
Correct only Z by this macro, then remesh it

ok. I see... thanks again!

I tried previously to adjust the Z using the "Detailed correct" function in order to push the nodes to plane Z=4.2m. Many of them were correctly adjusted but some of them were left with innacurate 4th digit (like 4.2003). I have no such problem using your tool.

Re: Meshing problem

Artur.Kosakowski — Mon, 15 Oct 2012 12:23:42 GMT

When you used the detailed correction you most likely clicked on 3 points to indicate Z=4.2 plane having the coordinate display precision set to either 0.12 or 0.123. In this way you were not able to see what plane exactly you defined. To make sure it is 4.2 edit manually the coordinates for the indicated points e.g.

Point 1: x, y, 4.20 (and not displayed 003)

after edition

Point 1: x,y, 4.2 (delete the last displayed 0 to get rid of unwanted part).

Re: Meshing problem

Anonymous — Mon, 15 Oct 2012 13:28:09 GMT

@Artur.Kosakowski wrote:
To make sure it is 4.2 edit manually the coordinates for the indicated points

Since you told me that the position of some nodes are not accurate, I increased the display precision up to 4 digits which I guess should be enough.

Initially I did the way you expected i.e. i selected 3 nodes and it was much worse. A lot of nodes were still out of 4.2 plane. Then, I enetered manually the coordinates of 3 non-collinear points at 4.2m elevation. and I got better results but still as I said it didn't fixed all of them.

Anyway, I have to be much much more careful developing the model as the object snap is very tricky and it seems that you may end up quickly with misplaced nodes. When creating the objects I rely a lot on local systems and maybe this was the source of error... But, I don't know how else I could have done it otherwise...

Thanks again!

After fixing the position of all nodes the model is working well now.

Re: Meshing problem

jo2ny — Mon, 15 Apr 2013 13:53:20 GMT

Hi,

I''m also having a problem with the meshing.

I tried the "To Plane" correction of the current wall (see picture attached).

I also tried the Round Up coordinates tool, but still not working...

I ran out of ideas

Please help me figure this out. I also tried deleting and redefining the wall and still nothing...

Thanks in advance

Re: Meshing problem

Rafal.Gaweda — Mon, 15 Apr 2013 14:03:23 GMT

Robot file please

Re: Meshing problem

jo2ny — Tue, 16 Apr 2013 06:12:06 GMT

here is the model,

https://www.yousendit.com/download/UVJpak93UzgrV3g3czlVag

Thanks

Re: Meshing problem

jo2ny — Tue, 16 Apr 2013 07:00:31 GMT

i got a lot of nodes in the model, that should have been deleted after mesh deleting.

i can't get rid of them, "delete" is not working

Re: Meshing problem

Rafal.Gaweda — Tue, 16 Apr 2013 09:08:43 GMT

1. you have to open this file in repair mode to be able to delte these 61000 "not existing" nodes.

2. I suggest to mesh model with FEs size 0.2m

3. Corrected model attached.

Re: Meshing problem

jo2ny — Tue, 16 Apr 2013 12:47:04 GMT

THANKS A LOT!

This Repair Mode, is a new feature in ARSA 2013? (i'm currently running the 2012 version)

Re: Meshing problem

Rafal.Gaweda — Tue, 16 Apr 2013 12:56:45 GMT

It has existed for many years.

File \ Open ; on window -> Repair Mode checkbox on the right hand side

Re: Meshing problem

jo2ny — Tue, 16 Apr 2013 13:56:21 GMT

Got it

Thanks again!

Re: Meshing problem

Anonymous — Tue, 28 May 2013 03:44:22 GMT

Dear all

WHen I meshing for my stair then error

please see picture

Thanks all

Re: Meshing problem

Rafal.Gaweda — Tue, 28 May 2013 07:09:52 GMT

1. Assign objects properly to stories

2. Diaphragms can be used only for horizontal panels. Use Shell calculation model for stairs panels.