topic Re: Problems making holes in solid elements in Robot Structural Analysis Forum

Problems making holes in solid elements

SMVZWDPY — Tue, 03 Sep 2019 12:55:37 GMT

I'm trying to model holes in a specific steel beam . The beam is modeled using volumetric finite elements, with geometry imported from a cad-model.

I've tried using this thread for guide line, however it does not work for me. https://forums.autodesk.com/t5/robot-structural-analysis-forum/3d-solid-modelling-in-robot/td-p/4916648

(mind the seperate cylinders are only used for making holes, and shall be deleted after)

Does anybody know what i'm doing wrong?

Regards

Re: Problems making holes in solid elements

Krzysztof_Wasik — Tue, 03 Sep 2019 14:57:08 GMT

Hi @SMVZWDPY

You have to redefine small tubes as Solid modeler objects

Remove mesh from whole model

Open Tools >Job preferences >Work parameters and switch on Define by default in Solid Modeler format

then redefine tubes 4 6

Then you can use Edit >Edit solids and faces>Objects combination method Subtraction A-B

Once one hole is on 2 segments border small tube should be subtracted from objects 1 and 2 in separate operation (so once it disappears after subtraction it is useful to copy it before first operation then move copied object to initial position and use it for second operation)

Attached you will find model

If I managed to answer your question(s) press the Accept as Solution button please. This will help other users to find solution(s) much faster. Thank you.

Re: Problems making holes in solid elements

SMVZWDPY — Wed, 04 Sep 2019 06:04:28 GMT

Hi Krzysztof

Thanks a lot, that solved my problem!

I got a a few extra questions i hope you can answer:

Should "define by default in a solid modeler format" always by ticked on, when using 3D elements ?

Also, I want to make the mesh more fine, however when i reduce the mesh size in meshing options, nothing really happens in the model. Is this due to way the beam is modeled or do i make another mistake?

Thanks again.

Regards

Re: Problems making holes in solid elements

Krzysztof_Wasik — Wed, 04 Sep 2019 07:22:06 GMT

Hi @SMVZWDPY

Solid modeler is more effective once you combine object (but less effective in meshing)

In your model you have tried to combine 2 different objects. imported part was in solid format, extruded small tubes were in default format. This was reason for problem with object combining

For mesh refinement

select object (s)

open meshing options

reduce mesh size

then re-mesh structure using local mesh generation for selected objects

for 0.03

for 0.01

If I managed to answer your question(s) press the Accept as Solution button please. This will help other users to find solution(s) much faster. Thank you.