Robot Structural Analysis Forum
Welcome to Autodesk’s Robot Structural Analysis Forums. Share your knowledge, ask questions, and explore popular Robot Structural Analysis topics.
cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

2016 Mesh problem

21 REPLIES 21
Reply
Message 1 of 22
Anonymous
1187 Views, 21 Replies

2016 Mesh problem

Hi,

We have carried a model in shell in 2012. The mesh appeared correct and the anaylsis was as we expected.

 

We have then carried out all the same process in 2016 and I am getting strange visual colouring and meshing problems.

 

Can some one please review and see where I am making the mistake or is it an error in 2016.

 

The model can be downloaded from the below link and I have attached the porblem panels.

 

A quick response would be good.

 

http://we.tl/X3NQJ1koVT

 

Thanks

21 REPLIES 21
Message 2 of 22
Rafacascudo
in reply to: Anonymous

If the meshes were correct ,Open the 2012 model in RSA 2016 and freeze all the meshes , if you hadn´t already done that.

freeze mesh.jpg

Rafael Medeiros
Did you find this post helpful? Feel free to Like this post.
Did your question get successfully answered? Then click on the ACCEPT SOLUTION button.

EESignature

Message 3 of 22
Anonymous
in reply to: Rafacascudo

Hi

 

 

Unfortunately I have updated to 2016 and no longer have 2012 so I am unable to do this.

Also I am wondering why it did not mesh correctly in 2016 now that I have to use it all the time.

 

Thanks

Message 4 of 22
saclovitzky
in reply to: Anonymous

Can you show a screenshot of your "advanced meshing options"?

Message 5 of 22
Anonymous
in reply to: saclovitzky

Hi

 

Not sure if this is what you mean -if not where do I get advanced mesh options

 

Options.PNG

Message 6 of 22
saclovitzky
in reply to: Anonymous

Pls. see attached

Message 7 of 22
Anonymous
in reply to: saclovitzky

Hopefully this time

 

Options 2.PNG

 

 

Message 8 of 22
saclovitzky
in reply to: Anonymous

try to remesh everything by following simple steps as attached.

Message 9 of 22
Rafacascudo
in reply to: saclovitzky

It´s not that simple .

For example, the model has a retangular panel with 3mm X 6565mm dimensions with a 2,75mm thickness and a  2cm mesh size.

It also has solid circular bars with 1mm diameter and 1mm of lenght. I guess they are used as contact elements ( compression only truss bars)

What kind of structure is that , so we can help you better in the modelling process?

Rafael Medeiros
Did you find this post helpful? Feel free to Like this post.
Did your question get successfully answered? Then click on the ACCEPT SOLUTION button.

EESignature

Message 10 of 22
Anonymous
in reply to: Rafacascudo

                    

You are correct, the 1mm bars are to repersent contact memebers.

 

What I am trying to model is a steel transom with the eccentric load from the glass setting on the front edge. The transom spans the 6.705m but its only the begining of a model as I will need stiffer connections at the ends and some kind of truss etc for such a large span.

 

See below

section.PNG

Message 11 of 22
Rafal.Gaweda
in reply to: Anonymous


 

Can some one please review and see where I am making the mistake or is it an error in 2016.

 

"Colouring issue" because of small width of panels. This is my guess.

 

 



Rafal Gaweda
Message 12 of 22
Anonymous
in reply to: Rafal.Gaweda

     

 yes, 
I thought this was only visual, but what do you think about the meshing problem??
Message 13 of 22
Rafal.Gaweda
in reply to: Anonymous

I do not see any:

 



Rafal Gaweda
Message 14 of 22
Anonymous
in reply to: Rafal.Gaweda

                          When I do the same steps as you I still get the wrong mesh between panels 3 and 4. See below image of Front view you can see mesh not correct. Is yours the same??

Capture1.PNG

Message 15 of 22
Rafal.Gaweda
in reply to: Anonymous

Corected model attached

(Select these nodes and run detailed correction to line to upper edge ; additionally : nodes  31 104do116K4 359 426do435K3  were not recognized by meshing panel 12 so I added lines between them to mesh correctly panel 12 with these nodes)

 



Rafal Gaweda
Message 16 of 22
Anonymous
in reply to: Rafal.Gaweda

Thank you Rafal.Gaweda         I have progressed the model and everything was working well and I was getting results after each change I made. But now I have added 4 compression bars and now it will not analyse. Can you tell me why it will not anaylse now. I have attached the model that was working and the model not working.

 

The location I have added the compression bars are at the same location on both sides and can be seen in the the attached screen captures.

 

Please help as I have been trying to figure it out all day!!

 

Link for files

http://we.tl/1Es9d7sjFX

 

Thanks

 

 

Message 17 of 22
Anonymous
in reply to: Anonymous

Hi Rafal.Gaweda  was wondering did you get a chance to review the above problem? I know you likely busy but have to provide result today if possible and I have still to add parts.

Thanks

Message 18 of 22
Artur.Kosakowski
in reply to: Anonymous

I have isolated the part of the structure where you defined these compression only bars and applied fixed supports at the outer ends of them. You can see that there is no convergence either and the simple reason is that under self-weight they have to transfer tension to keep the structure stable which they as being compression only can't do. Are you sure that you want them to be compression only rather than tension only?

 

compression only bars.PNG

 

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
Message 19 of 22
Anonymous
in reply to: Artur.Kosakowski

Hi

Thanks for getting back to me. 

Yes, i need to be compression only, I am using them as to represent contact members only between inside plates and wall of outside plate. Is there any other way of doing this?

 

The inside plates are only slid inside locally and look like the attached.

 

Thanks

Message 20 of 22
Artur.Kosakowski
in reply to: Anonymous

Please look at the picture I attached to my previous answer and focus on the vertical compression bars e.g. the ones between nodes 2106 and 2017 as well as 2010 and 2011. Assuming that thy represent the vertical bolts

 

vertical bolts.PNG

 

they should be tension only bars. In other words if you look at the model I attached and you remove these short vertical bars (as they are compression only and self-weight acts downwards causing tension in them) as they are not going to work what would restrain the model against the vertical movement? 

 

If you set them as tension only and keep the horizontal (bolts) as compression only the analysis will converge.

 

 



Artur Kosakowski

Can't find what you're looking for? Ask the community or share your knowledge.

Post to forums  

Autodesk Design & Make Report