Partitioning an existing surface

[mike_kertrain]

Good day everybody,

I'm testing out the trial version of Simulation Muliphysics and I have a question about partioning and applying surface loads.  I am relatively new to the Autodesk environment so this might be a very basic question.  I am coming from an Abaqus and ANSYS background.

Can I not partition an exisiting surface to add a surface load to a specific area of the part?  Please see the attached figure.  The inside of the hole is defined by surface 1 and surface 2.  I'd like to imitate a pin (as a surface pressure) acting on the the hole within the yellow lines.  However, I cannot select that region without selecting the entire inside surface of the hole.  I'm assuming that there is an easy way to do this but I haven't come across anything yet in this forum.

Any help would be appreciated.

-MB

[John_Holtz]

Hi MB,

Out of curiosity, how would you do it in the other products you mentioned?

In Simulation 2013, one option would be "Setup > Loads > Bearing". You can apply this load to the "entire" surface of the hole, but the software knows to only apply the parabolic-like load to the portion that is plus or minus 90 degrees to the radial direction that you specify.

The second option would be to split the surface of the hole in your CAD software. If you want the load over a very specific area, this is the best method.

With the third option, you have limited control over the area. Simulation is a line-based modeler (compared to other codes that generate elements directly), so what you do is select the lines and change the surface number of those lines. Specifically

1. Select the lines ("Selection > Select > Lines" and probably "Selection > Shape > Polyline")
2. Check what surface numbers are used (expand the "Surfaces" branch in the browser for the part)
3. Change the surface number of the selected lines ("Draw > Modify > Attributes") to a surface number not used in that part.
4. Apply the load to the new surface.

[tfjield]

Hi John,

If I'm using your method 3 that you outlined in the previous message, do I need to select all the lines of all the element faces inside the region that I want to apply the load, or can I just select the lines that create a bounding box?  Meaning that if I apply a surface load to a surface defined by a bounding box, will the software automatically apply the surface load to all of the element faces comprising that surface within the bounding box?

Thanks,

Todd

[John_Holtz]

The short answer is that you need to select all of the line.

The technicalities are as follows:

• For brick elements, you only need to change the majority of the lines on an element face (3 of 4 lines or 2 of 3 lines) to change its surface number.
• For plate/shell elements, the highest surface number of any of the lines that form the element will get a load applied to that surface. So you really need to be careful at the border between elements on surface A and elements on surface B.
• For 2D elements, you just need the one line that is on the "surface" of the imaginary 3D.

[blwisema]

This video will explain how:

http://engineeringexploration.autodesk.com/content/module-2-editing-non-native-imported-geometry

Hope thats what you're looking for