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Help with Hex Meshing of this Part

Pioneer
Pioneer

Folks,

I was wondering if someone could help me hex mesh this component...mainly interested in the work flow i.e. how would one go about partitioning the solids etc. When working with solids, I usually prefer to do an extrude of a surface mesh. I am attaching the step file.

 

01.PNG

 

Also, just curious, how can I update solid element CSYS orientation in Femap?

 

Thx

4 REPLIES

Re: Help with Hex Meshing of this Part

Siemens Phenom Siemens Phenom
Siemens Phenom

Use the Meshing Toolbox and create a "Pad" on one of the small holes -

t1.jpg

 

Use Geometry - Solid - Embed Face and embed the four pad faces into the entire solid -


t2.jpg

 

Now, some regular slicing - now 32 separate solids -

t3.jpg

 

Set Mapped Meshing Approaches on the 8 Pad Surfaces on the end and

Size for Hex Meshing - 

t4.jpg

Hex Mesh -

t5.jpg

And, if we mesh the top four corner surfaces before hex meshing with the "Max Quads" option turned on, we can remove the couple of triangles and make sure there are not wedges in the following hexa mesh -

t6.jpg

 

t7.jpg

With some more mesh control -

t8.jpg

 

Attached file contains a v11.3 Neutral File of the above model.

 

Mark.

Re: Help with Hex Meshing of this Part

Solution Partner Phenom Solution Partner Phenom
Solution Partner Phenom

Hello!,

As add-on to Mark post using the general method I want to show a simply meshing approach that I use a lot with HEX meshing: the great MESH >SWEEP >ELEMENT command + MODIFY > ASSOCIATIVITY > AUTOMATIC command.

1.- SOLID SLICE your 3-D model to take advance of 1/8 symmetry. Also use comannd GEOMETRY > CURVE-FROM SURFACE >SLICE to imprint the hole solid with curves after slicing with two planes.

3dhole1.png

2.- Perform a mesh sizing and 2-D mesh using the MESHING TOOLBOX, the idea is to extrude 2-D QUAD elements to genertate 3-D SOLID HEXA elements.

3dhole2.png

 3.- The small hole region is the most complex: the extrusion is not possible, then use 2-D QUAD Mesh of both TOP and BOTTOM regions with command Mesh, Geometry, HexMesh from Elements...

HexMesh From Elements provides two ways to create a hex mesh out of mapped surface quads. A hexahedral mesh can be created from a fully enclosed outer bound of mapped surface quads or between a bottom and top mapped region that is connected with straight lines.

3dhole3.png

The result is this excellent HEX mesh:

3dhole4.png

 4.- For the other region use command SWEEP: select the surface 2-D mesh and next sweep them along the two curves to form the new 3-D solid elements, all in one operation!!.

3dhole5.png

The resulting mesh will have an exceptional quality. Don't forget to use command TOOLS > CHECK > COINCIDENT NODES to merge ALL coincident nodes, OK?.

3dhole6.png

5.- This is 1/8 PORTION, simply use command MESH > REFLECT > ELEMENT to repeately recreate the full 3-D model.

3dhole7.png

And of course, to finish do the following:

  • MERGE nodes of the full mode.
  • Geometry, Solid, Add... to have only ONE solid.
  • Modify >Associativity > Automatic to associate the nodes of selected elements with selected solid. In addition to the nodes and elements being associated to the main entity (solids or surfaces/sheet solids), they will then also be associated to the surfaces of solids, curves on those surfaces, and points on those curves allowing you to use geometry based commands in FEMAP (i.e., Loads and Constraints on geometry, any selection method using a geometric entity, etc.).

Hope it helps!!.

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: Help with Hex Meshing of this Part

Pioneer
Pioneer

Folks,

Thanks for the replies. Learned a thing or two from your responses. I was able to Hex mesh the part after slicing, but the refinement level, especially near the details was not as good as above ones.

 

 

Re: Help with Hex Meshing of this Part

Solution Partner Phenom Solution Partner Phenom
Solution Partner Phenom

Hello!,

To learn more go to my BLOG and search for HEX MESHING, here you are:

https://iberisa.wordpress.com/2011/10/16/mallado-con-elementos-hexaedricos-hex-meshing-iii/

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/