Refine mesh

[MartinaC 2]

Hi everyone,

I modeled an element in Altair Inspire, then I imported it in HyperWorks as a Solver deck. The mesh is created by Inspire, is there a procedure to refine the mesh o remesh the object? I tried to remesh some volumes, but the longest side of the FEs was not divided.

 

Bests

Martina

[Rahul R 309]

Do you want to keep mesh of two layers across thin region?

[MartinaC 2]

I want to reduce the dimension of the FE in some regions. I am modeling a tensile test coupon with PSOLID card image.

[Rahul R 309]

If you want to change the dimension of FE model then you could make use of morphing technology in HyperMesh.Please share the screenshot of the region you want to make changes.

[MartinaC 2]

Ok, thank you. Could you explain me the procedure or indicate a guide or some tutorials, please?

 

The region is more or less the included one inside the white line (hw). I would like to obtain a gradual refinement like in the second shot (hw1), or something like the third image (hw2)

 

Bests

Martina

 

 

 

 

[MartinaC 2]

Where I can find information about imported meshes and modification of them?

 

Martina

[Q.Nguyen-Dai 291]

Don't make TET mesh with this simple geometry!!!

Here's the best way to go:

 

[MartinaC 2]

Thank you.

I used tetra mesh because that was only the beginning of the work. Now I have an hollow steel joint to be modeled as AM metal. I have to use 3D element mesh.

The existing mesh has been generated in Altair Inspire to perform optimization, but I am not able to refine the mesh woth the refinement box.

 

Bests

Martina

[Q.Nguyen-Dai 291]

@MartinaC : Is this TET4 or TET10 mesh?

 

[MartinaC 2]

I think tet4, because Altair Inspire SolidThinking create first order elements. The mesh was created due to optimization procedure in Inspire, then imported in HyperWorks.

[Q.Nguyen-Dai 291]

TET4 mesh with only two elements on thickness? Hmm, please don't do analysis with this mesh, because you will got bad results.

 

[MartinaC 2]

This is the reason why I want to refine it, but I am not able to refine it. Can you explain how can I do it? Keeping in mind this is a model imported from Inspire.

[Q.Nguyen-Dai 291]

Could you share this model?

[MartinaC 2]

Attached the model and the session.

Nodo.hm Nodo.mvw

[Q.Nguyen-Dai 291]

How do you assemble the central part with others?

 

[MartinaC 2]

They have frozen contact surfaces generated by Inspire: elements with distance were created with Rhino, then the IGES file was imported in Inspire, the elements moved to have contact and the contact surfaces set to freeze. The obtained model was optimized and exported as .fem file, then imported in HyperWorks as Solver Deck.

[Rahul R 309]

Do you have actual CAD model?

In HyperMesh 2017 and 2019 we have some good features for 3d meshing.Fuse and 3d tet mesh with layers across thin region would be useful in your case.

[MartinaC 2]

Thank you!

I have another proble.:

I used STEP file to define the internal region of the node (which is the optimized one), then I imported as geometry from CAD model the other parts. I checked the edges and useed the edge edit equivalence to obtain a close surface. Then I used 2D mesh in the region that require a finer mesh, then I create the tetra mesh. I impose a simple tensile non-linea quasi-static load and run the analysis: the software writes "Ready", but the Optistruct window does not appear.

I used the same procedure (except fot the STEP file) for the coupon bar, and that analysis run. I really do not know what to do.

 

Bests

Martina

[MartinaC 2]

I attach model and session, if needed I can attach the .fem file.

 

I thought to some problems:

 - the internal surface built from STEP file (created using the option "skin" of surfaces) generates problems with the geometry imported from Rhino.

 - the number of elements and nodes is too high for the computer I am using.

 - closed surfaces are requested and contact surfaces must be defined, instead of using open surfaces (I used them to ensure the tetra mesh generates with the same pattern of the adjacent body.

 

In the model there are empty components because they are the layers from the geometry (Rhino). I defined the 2D mesh of some surfaces of those layers (to perform the mesh in an easier way), then I moved them in a unique component (Nodo)

07.01_2.mvw 07.01_2.hm

[MartinaC 2]

I tried to define the model entirely from STEP file, exported from Inspire, but there is the same problem.

Here I used only the central part to check the mesh procedure: all surfaces were attached to solids (closed surfaces). I delete the external parts and meshed only the central one.

A 2D mesh was created, than the tetra mesh. All 2D elements were delated after tetra mesh was generated.

 

Bests

Martina

07.02_2.hm 07.02_2.mvw

[Q.Nguyen-Dai 291]

I see you got not-bad tet mesh. So where's your problem?

 

[MartinaC 2]

The problem is that when I launch the non linear quasi static analysis the analysis does not begins: at the bottom of the window there is the written "Ready", but the Optistruct window does not open.

[MartinaC 2]

With my professor we thought the model was numerically too complex to be analyzed. So we simplified the model with a scheme and analyzed its behavior.

 

Thanks for your support

Martina