topic Re: 2016 Mesh problem in Robot Structural Analysis Forum

2016 Mesh problem

Anonymous — Wed, 06 Jan 2016 09:29:08 GMT

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

Re: 2016 Mesh problem

Rafacascudo — Wed, 06 Jan 2016 12:53:20 GMT

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

Re: 2016 Mesh problem

Anonymous — Wed, 06 Jan 2016 13:08:35 GMT

Rafacascudo

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

Re: 2016 Mesh problem

saclovitzky — Wed, 06 Jan 2016 15:01:04 GMT

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

Re: 2016 Mesh problem

Anonymous — Wed, 06 Jan 2016 15:06:09 GMT

saclovitzky

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

Re: 2016 Mesh problem

saclovitzky — Wed, 06 Jan 2016 15:28:35 GMT

Pls. see attached

Re: 2016 Mesh problem

Anonymous — Wed, 06 Jan 2016 16:02:30 GMT

Hopefully this time

Re: 2016 Mesh problem

saclovitzky — Wed, 06 Jan 2016 16:52:42 GMT

try to remesh everything by following simple steps as attached.

Re: 2016 Mesh problem

Rafacascudo — Wed, 06 Jan 2016 20:24:59 GMT

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?

Re: 2016 Mesh problem

Anonymous — Thu, 07 Jan 2016 08:41:06 GMT

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

Re: 2016 Mesh problem

Rafal.Gaweda — Thu, 07 Jan 2016 09:16:59 GMT

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.

Re: 2016 Mesh problem

Anonymous — Thu, 07 Jan 2016 09:20:16 GMT

Rafal.Gaweda

yes,

I thought this was only visual, but what do you think about the meshing problem??

Re: 2016 Mesh problem

Rafal.Gaweda — Thu, 07 Jan 2016 09:42:50 GMT

I do not see any:

Re: 2016 Mesh problem

Anonymous — Fri, 08 Jan 2016 08:47:41 GMT

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??

Re: 2016 Mesh problem

Rafal.Gaweda — Fri, 08 Jan 2016 10:38:25 GMT

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)

Re: 2016 Mesh problem

Anonymous — Mon, 11 Jan 2016 16:45:20 GMT

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

Re: 2016 Mesh problem

Anonymous — Tue, 12 Jan 2016 08:43:08 GMT

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

Re: 2016 Mesh problem

Artur.Kosakowski — Tue, 12 Jan 2016 09:20:52 GMT

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?

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: 2016 Mesh problem

Anonymous — Tue, 12 Jan 2016 09:33:58 GMT

Artur.Kosakowski

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

Re: 2016 Mesh problem

Artur.Kosakowski — Tue, 12 Jan 2016 09:52:48 GMT

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

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.