SOLID FEM TEXT FORMAT

[mgaafar]

Hi, is there a way to write an .str file with FEM solids. I am trying to input the nodes and the FEM elements in to Robot command line but I failed. I saved a meshed solid model to .str and only the nodes were created, so I manually extracted the FEM from the soild tables and tried to add them to the .str file under the following commands:

QUAdrangular 4 : for tetrahedron

QUAdrangular 8: for 8 noded elements

but the FEM appears as distorted FEM and not as solid.

my knowledge about the API is so premative so I am trying to find a solution with text file because Solid FEM tables in RSA are not editable.

Thanks

[Rafal.Gaweda]

I am afraid there is no such syntax in str file.

Full str syntax description can be found:

"c:\Program Files (x86)\Common Files\Autodesk Shared\Structural\Help\2013\R97mod01.doc"  (in english, similar files in ither languages).

What do you change? Why to you want do "edit" them?

[mgaafar]

I want to edit/manipulate them because sometimes after spending hours in meshing, I find some parts are not meshed. I tried to fill the empty parts by copying other FEM but it says that this copied FEM is not part of any panel. also because of the small mesh size, the model is very slow and it is very time consuming to move/edit/delete elements.

Also I am thinking of using other free softwares that effeciently meshes solid elements and then export it to RSA.

[Rafal.Gaweda · Accepted solution]

 I tried to fill the empty parts by copying other FEM but it says that this copied FEM is not part of any panel. 

Exactly. This way will not work.

Also I am thinking of using other free softwares that effeciently meshes solid elements and then export it to RSA.

---

We did something like that years ago.

ANASYS mesh file (not ansys data file, it was possible to save meshes only from ANSYS in special text file) converter to neu format , then it was possible to read neu file in Robot.

I am attaching this converter for your consideration - I do not know if it works or not now.

[mgaafar]

Hello Again Rafal, So it seems that the Excel file does not properly convert the ANSYS text files(nodes and elements) to .NEU file that ROBOT can read. it created the file with no problems but ROBOT was not able to extract the data properly.

now I have not tried using the API yet, but to save me sometime, Can you quickly answer the following questions:

1- Does the API allow me to create manually FEM for solid (defined by nodes and FEM connecting to these nodes) or not?

2- if the answer of the first question is YES, then can robot analyse model full of Solid FEM without been assigned to SOLID PAnel?

3- Can API define Solid panels (regular or irregular)? and assign a predefined FEM solid to the solid panel?

Thanks

Thanks

[Rafal.Gaweda]

3 x NO

Pleae send me these Ansys files,neu also.

[mgaafar]

Rafal, Please find attached in the link below the ansys file, converted file from your excel and nodes and elements xt files.

http://www.4shared.com/zip/bl6QaGxl/converted.html

[Rafal.Gaweda]

These text files are wrong. They should contain pure information about node numbers + their coordinates ; FE numbers+ their nodenumbers.
I will clear them and I will check

[Rafal.Gaweda]

ANSYS mesh should be finaly stored in 2 files in such "syntax":

Nodes file:

8- node FEs file:

Then you can use attached xls with new macro to convert them to neu file and read neu file in robot

Then... good luck 🙂

Files : http://we.tl/qCIDW3oLlS

[Rafal.Gaweda]

UNfortunately ANSYS \ ALGOR can generate "degenerated" 8 node (degenerated to 5 6 7 node) elements and robot is not capable to support them.

You can try to force it(if possible) to generate ONLY not-degenerated 8 node elements (then use my macro to create neu file) or force it to generate ONLY 4 node tetrahedrons. If you have the text files for them I can make \ correct macro and try to generate new neu file.

[mgaafar]

Thank you very much Rafal for your effort.

Yes, I noticed that there was an error when I ran the analysis "Execution problem No:3304"

also besides, is there a problem to FEM without being assigned to solid panel? now I will have to assign loads manually on the nodes, and I am not sure how to assign selfweight to the FEM parts without solids?