topic Drawing radius plate. in Simulation Mechanical Forums (Read-Only)

Drawing radius plate.

Anonymous — Mon, 07 May 2018 00:53:37 GMT

Hi, I am trying to run an FEA on an acrylic element. I am drawing the radius plate in sim studio and importing it into simulation mechanical. Issue is the radius plate is technically multiple parts. I have tried stitching, merging and just about everything I can think of. Hydrostatic load from convex face.

Suggestions?

Re: Drawing radius plate.

Anonymous — Mon, 07 May 2018 14:56:13 GMT

any help would be greatly appreciated.

Re: Drawing radius plate.

John_Holtz — Mon, 07 May 2018 15:19:50 GMT

Hi @Anonymous

I am not clear what the problem is.

If you have multiple parts in Sim Mech but want it to be one part, that should not be a problem for the final results. Just enter the Element Definition and material properties for the multiple parts. Sim Mech doesn't care whether it is one part or multiple parts.
If you have one part in Sim Mech but you want it to be multiple parts, you will have to mesh the model first, then select the lines that you want to be on a different part, then change the part number for those lines (right-click > Modify > Attributes > Part number"). But in some analysis types, you can use the surface number of the part to enter the properties that you want without needing separate parts.

If that doesn't help, please provide the SimStudio file or Sim Mech archive (app button > Archive > Create) and let us know specifically what you are trying to do and why it is not working.

Re: Drawing radius plate.

Anonymous — Tue, 08 May 2018 06:06:53 GMT

This part is used as an aquarium window. Hydrostatic loading is from the convex face.

I have imported the component into simulation mechanical from simstudio.

I have applied translational restraints to represent simple support.

I am applying hydrostatic loading to each part. However, loading is not displaying on the correct face. Red arrow indicates the director I wish to have the force orientated in.

Re: Drawing radius plate.

Anonymous — Tue, 08 May 2018 06:07:42 GMT

image 4,5,6

Re: Drawing radius plate.

Anonymous — Tue, 08 May 2018 06:08:22 GMT

image 7,8,9

Re: Drawing radius plate.

Anonymous — Tue, 08 May 2018 06:08:55 GMT

image 10

Re: Drawing radius plate.

John_Holtz — Tue, 08 May 2018 13:47:37 GMT

Hi Sean,

This now seems to be unrelated to whether you have 1 part or multiple parts.

You need to define the "Normal Point" for the plate elements in the Element Definition. See this article (and the links to the additional articles): How to flip the direction of Hydrostatic Pressure on Plate elements in Simulation Mechanical

In other words, a plate element has no clear distinction of how the element is oriented and which side is "top", "bottom", "inside", "outside", "whatever you want to call it". (A solid model has a clear "outside" and "inside" because of the volume mesh.) The user tells the software which side of the plate element is the "bottom" side by specifying the Normal Point in the Element Definition. In many cases, you choose which side is more convenient to be the bottom. In your case, it makes sense to define the Normal Point like this:

This would cause a positive pressure to be oriented as shown. In your case, you want the pressure in the opposite direction, so enter a negative fluid density.

Re: Drawing radius plate.

Anonymous — Tue, 08 May 2018 15:30:41 GMT

Pictures 1,2,3,4,5: In element definition I selected the normal point for both positions using the point selector. Does this look ok?

Pictures 6,7,8,9,10,11,12: I applied a hydrostatic load.

Picture 13: Shows incorrect arrow location in one node column.

Picture 14,15: Show the the incorrect vector

Picture 16,17,18: Applied negative fluid density.

Picture 19,20,21: Ran new design and confirm results. shows correct vector.

Does this look correct?

Re: Drawing radius plate.

Anonymous — Tue, 08 May 2018 15:39:34 GMT

pictures 1,2,3,4,5: selected normal points.

pictures 6,7,8,9,10,11,12,13: applied hydrostatic load.

pictures 14,15: ran results and confirmed incorrect vector.

pictures 16,17,18: changed fluid density to negative.

picture 19,20,21: checked new results. confirmed correct vector.

Does this look correct?

As you can see one node column still displays the opposite vector in the editor. Is this an issue? If so how do I fix?

Re: Drawing radius plate.

Anonymous — Tue, 08 May 2018 15:40:25 GMT

pictures 4,5,6

Re: Drawing radius plate.

Anonymous — Tue, 08 May 2018 15:41:03 GMT

pictures 7,8,9

Re: Drawing radius plate.

Anonymous — Tue, 08 May 2018 15:41:42 GMT

pictures 10,11,12

Re: Drawing radius plate.

Anonymous — Tue, 08 May 2018 15:43:12 GMT

pictures 14,15,16

Re: Drawing radius plate.

Anonymous — Tue, 08 May 2018 15:43:55 GMT

pictures 17,18,19

Re: Drawing radius plate.

Anonymous — Tue, 08 May 2018 15:44:31 GMT

pictures 20,21

Re: Drawing radius plate.

John_Holtz — Tue, 08 May 2018 18:38:27 GMT

Hi Sean,

Most of the attached images are 320x240 pixels; way too small to see anything.

What I will say is that what is shown in the FEA Editor "does not matter". Those are just a bunch of lines and symbols that eventually are translated into something the analysis understands. So the fact that one set of arrows is pointing in the wrong direction may not be critical.

What counts is what is shown in the Results environment. If the pressure arrows are in the correct direction, all of the elements connected together, etc, then the results are correct. At that point, it just becomes a question of whether the input is correct and whether the mesh is fine enough to capture the effects you are after.

For future reference, Windows includes a "Snipping Tools" to capture the screen (or a portion of the screen) at full resolution and save the image to a file (PNG format maintains the clarity better than JPG or GIF). Then you can select the multiple images using File Explorer, right-click "Send To > Compressed (zipped) folder" to put all of the images into one file that can be attached to the forum. That will make it easier than creating multiple posts to upload all of the files. (It also makes it easier for us to download the images and look at them.)