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Defining Ansys Superelement SUB File Manually

Photo by  James Owen  on  Unsplash A surprisingly popular blog-post written here is Exporting Stiffness Matrix from Ansys . A sensible follow up question is what can one do with the exported stiffness matrix? In a recent Xansys Forum post, a question was raised on how we can edit the stiffness matrix of a superelement and use it for our model.  An approach presented below is to first create a superelement that has the same number of DOF and nodal location that will serve as a template. An APDL script can then be written to edit the stiffness matrix entries as desired before exporting to a new superelement *.SUB file for use in future models. The self-contained script below demonstrates this.  /prep7 et ,1, 185 mp , ex, 1, 200e3 mp , prxy, 1, 0.33 w = 0.1 ! single element (note nodal locations) n , 1, w, -w, -w n , 2, w, w, -w n , 3, -w, w, -w n , 4, -w, -w, -w n , 5, w, -w, w n , 6, w, w, w n , 7, -w, w, w n , 8, -w, -w, w e , 1, 2, 3, 4, 5, 6, 7, 8 /solu antype , substr     ! analy

SpaceClaim is Awesome

From the title, you could infer my feelings towards this nifty tool offered by Ansys. There are some who are still sticking to DesignModeler as their cleanup tool of choice. To those, I would implore you to give SpaceClaim a try. I believe the reason why some hold back from switching is due to the sunk cost fallacy. Learning DesignModeler has been such a significant learning commitment that giving it up becomes difficult.

A little known fact: the software could be accessed for free without feature restriction for personal education via the Ansys Student. Say you get an IGES file and it only imports as surfaces. You could stitch it together to create a solid, then save it as a STL file. Same as DesignModeler, SpaceClaim plays nice inside Ansys Workbench.

After going through the tutorials, here are my top tips I find useful:
1. Navigation - Alternative 2
I was tired of the indentation on my finger as I use the middle mouse button (MMB). My preference is Alternative 2 which uses the Right-mouse button (RMB) for navigation, freeing up the LMB for selection etc.
File > SpaceClaim Options > Navigation > Theme : Alternative 2

2. Keyboard Shortcuts
There are a few which are used so frequently and readily available like S for select, D for 3D mode, E for measure, P for pull etc. A few missing defaults which I use often are Split Body, Split and Project.
File > SpaceClaim Options > Customize> Shortcuts : Add...

3. Ctrl-Move
After selecting Move and a solid. One can hold down the Control key while doing the usual move. This would keep the original solid while creating a duplicate.

4. Measure > Check Geometry
A strange place to locate a tool to see if there are any difficult geometries. Note that sometimes there are false flags. If the problems are too troublesome to fix, it might be worth trying a simple mesh on the model any way.

5. Prepare > Show Contact
This is a great tool to verify where the geometry is expected to share nodes before moving it to Ansys Mechanical.

6. Copy-and-Paste
The almighty Ctrl-C and Ctrl-V works on most objects between windows! That means you could open up multiple models in multiple windows then copy and paste what you like to a new project.

7. Multiple Object Type Selection 
I didn't understand at first why one would want to select different objects (faces and bodies) in one go until I came to the problem of trying to do a parameter study of a cantilever beam with a few attached parts. After selecting the attachment bodies and single face at the end of the cantilever beam, the Move command can be made into a parameter that can be used in Design Xplorer to vary the length of the beam with associated parts moving in tandem.