1 Coord Sys for the CAD/FEM

[mechguy632]

Hello All,

After I have modeled say 2 parts and meshed them.

Firstly, How do I make the 2 CAD models refer to 1 coord system.

Secondly, How do I made 2 FEM models refer to 1 coord system after they have been appended.

Thank-you.

- mechguy

 

[christoph]

mechguy632: Do you want the two parts to be one part in Master Modeler? Or do you want them to be an assembly of two parts in Master Assembly? If the latter, you'll need to learn the Master Assembly task. If the former, I think you made a mistake by meshing your two parts before Joining or Adding the CAD parts, since joining or adding the CAD parts generally blows away most of your mesh.

Delete your FEMs, then Join or Add your two parts together. You'll essentially never be able to make the second part stop using its original CS, because model features are intricate and associative to their original CS. The only way you could easily do so is to delete your part History after Joining! Now your part is an orphan and has no CS nor modifiable features. Create a global CS, then Add your orphan part to your new CS. Now your entire CAD model references only one CS. Mesh it and the FEM will reference only one CS.

I'm currently unsure how to easily make an appended FEM reference the same CS as the destination FEM. Good question. If anyone finds the answer, I would like to know, also.

 

[christoph]

mechguy632: Regarding your second question, first let me warn you, it's generally unadvisable to alter or delete any CSs in the original solid (or surface) model if you wish to avoid destroying its correct history. So if you plan to delete any CSs in your FEM, it's advisable to first copy your original part and FEM, so that you don't change your original part.

Note: If a model or submodel needs to be moved or rotated, simply move it prior to the append. It doesn't particularly matter if its primary CS no longer lies on the global origin, since this can be changed (fixed) during the following procedure.

To make two or more appended FEMs reference the same CS (coordinate system), you must manually change all nodal displacement and reference CS references to the desired CS (e.g., CS1 or CS2). To list which CSs a node uses, select Simulation > Meshing > menus > Node > Full List. (There's no way in the software to determine which nodes are using a particular CS other than the above Full List command.) For all nodes that are not referencing the desired CS, simply change their nodal displacement and reference CS references to the desired CS using Node > Modify. Now you can delete all unreferenced CSs (if working on a copy of your part). The software will not allow you to delete any CS still referenced by any FEM nodes. So if you try to delete a CS and the software will not let you do so, then you know there are still nodes (or perhaps non-uniaxial gap elements) somewhere in your FEM referencing that CS.

To automatically disassociate your mesh and automatically delete all unreferenced CSs, if the you desire this for the copy of your part and FEM, delete the part history of the copied, appended FEM prior to performing the procedure described in the above paragraph. You are now free to delete the orphan feature of the part in this disassociated copy, if you wish. Good luck.