Hex mesh T tube joints

Creator
Creator

Hello everyone,

Does anyone know how to properly hex mesh a T tube joint in FEMAP?

 

I have tried several approaches, deviding the surfaces, extruding, etc. See the attached image for example.

 

A general approach for T tube joints of same diameter would be nice, if possible.

 

example.png

 

Thanks in advance.

9 REPLIES 9

Re: Hex mesh T tube joints

Solution Partner Phenom Solution Partner Phenom
Solution Partner Phenom

Dear Igor,

Is very easy, for instance a T-Join tube of external diameter Ø220 mm and thickness 10 mm:

HEX_MESH_TUBE_0.png

Simply split solid (use command GEOMETRY > SOLID > SLICE) using symmetry planes. Also use the length of the external arc to split the horizontal tube by plane X-Y. Next use the resulting distance "A" to split the vertical tube by plane X-Z. Also split the solid by the intersection plane of the two tubes, and you are done!.

HEX_MESH_TUBE_1.png

Next use an element size to have 3 elements in the thickness or so, you will need to "tune" the number of elements to have a regular "mapped" mesh, play with number of divisions using the MESHING TOOLBOX to have the same number of elements at opposite curves, here you are mine:

HEX_MESH_TUBE_2.png

And finally mesh the geometry using HEX elements, the resulting mesh will have the following element quality:

Check Element Quality
32655 Element(s) Selected...
No Elements Outside of Maximum Allowable Value.

   Quality Check               Number Failed      Worst Value
      Hex AR                             0           3.345548
      Hex DetJ                           0           3.713188
      Hex Warp                           0           0.999913
 
   0 Elements Failed out of 32655 Checked.

HEX_MESH_TUBE_3.png

Try yourself and enjoy!.

Best regards,
Blas.

Blas Molero Hidalgo, Ingeniero Industrial, Director
IBERISA • 48004 BILBAO (SPAIN)
WEB: http://www.iberisa.com
Blog Femap-NX Nastran: http://iberisa.wordpress.com/

Re: Hex mesh T tube joints

Creator
Creator

Hi Blas,

Sorry, i think i did not make my question very clear, i intend to mesh the full volume for a CFD simulation.

 

The volume inside a tube.

Re: Hex mesh T tube joints

Siemens Phenom Siemens Phenom
Siemens Phenom

Try using the command Geometry > Solid > Fill Hole and select one of the inner diameter arcs of the tube. 
You can then use the method that Blas has shown to slice the solid and hex mesh the part.

Before:

Before.JPG

After (hiding the original solid):

After.JPG

Highlighted

Re: Hex mesh T tube joints

Creator
Creator

Let me explain my problem a little further.

 

Here is all of my geometry:

 

full.png

 

Here are some of the joints, that are giving me trouble.

 

 

joints.png

 

This is an "OK" mesh for CFD:

 

mesh.png

 

The ideal would be to have the mesh that i plan to extrude all over the model, but i dont know if that will be possible due to the joints, so basically i am trying to hex mesh the volume including the joints.

 

This is just to elaborate further my problem in case anybody else looks at this post.

 

@Blas_Molero and @T_Giampietro

 

Thank you both for your sugestions, i am going to try that right now. If it works i will post the result here.

 

Att

Igor

Re: Hex mesh T tube joints

Creator
Creator

worked.png

 

Hello everyone,

It has worked when i followed @Blas_Molero's method.

 

@Blas_Molero thank you very much, i have a couple more question if you dont mind.

 

1- How do i plot the element quality like you did?

 

2- Do you think its possible to make a mesh like this :

 

mesh.png

Throughout the joints using the method you just posted? I'm going to try that now.

 

Thanks.

 

@T_Giampietro thank you very much too.

 

Att

Igor

 

 

Re: Hex mesh T tube joints

Siemens Phenom Siemens Phenom
Siemens Phenom

To plot element quality click the Contour Model Data button on the toolbar. 
Contour Model Data Toolbar.png
In the dialog box check "Show Model Data Contour" and expand Element Quality to select the criteria you would like to show. 


Contour Model Data.png

Re: Hex mesh T tube joints

Solution Partner Phenom Solution Partner Phenom
Solution Partner Phenom

Dear Igor,

Well, I can do it, but takes time, is not immediate, with multiple joints at different orientation many solid splitting are required, and to arrive to a consistent HEX mesh with multi-solid sizing at the same time is complex, not doubt. Hopefully FEMAP in the future can make it at the push of a button?, we will see!

 


 

2- Do you think its possible to make a mesh like this : 

mesh.png

Throughout the joints using the method you just posted?  


Best regards,
Blas.

Blas Molero Hidalgo, Ingeniero Industrial, Director
IBERISA • 48004 BILBAO (SPAIN)
WEB: http://www.iberisa.com
Blog Femap-NX Nastran: http://iberisa.wordpress.com/

Re: Hex mesh T tube joints

Creator
Creator
Many thanks, it worked Smiley Wink

Re: Hex mesh T tube joints

Creator
Creator
I see, i tried it for sometime and got some results but it is very time consuming. I hope too some improvements are made on hex meshing, it is crucial specially for CFD...
Anyway, thanks for the help Smiley Happy

Att