Two simple ansys questions

[Lorens]

Hello i have goten in some problems with my ansys model

1.How do you put pressure on lines on a solid model, now I place forces on each nod for hand, which is quit time consuming (i would guess that they want it 2d, but then i have to make a very very small area).

2 How do you deactivate certain elements for being listed or plotted? (commando?)

Thx for any help!
Kindly Paul-Martin

 

[CNAMITMA]

Hello,
For your first point :
Preprocessor/Loads/Define loads/Apply/structural/pressure/on lines
then select the lines where the pressure has to be applied.

I hope this will help you
Regards

 

[Lorens]

Thank you Cnamitma, but that don't seems to work on solid models for some reasons, I don’t get anything when I plot the stress or the displacement, but it works if you put the pressure on nodes, keypoints or areas.

 

[Lorens]

Sorry i mean forces on nodes, keypoints and pressure on areas.

Srry ...

 

[Drej]

You need to make sure that the pressure on the line is being applied properly. Two things to check:

Go to:

PlotCtrls>Symbols

and then go to the [/psf] surface load symbols box and select "Pressures", then go also to "Show pres and convect as" box and choose "arrows". Your pressures in the model should show as lines.

I have found that this doesn't always work, so to make sure you can transfer the solid model loads to the FE model using the command:

SBCTRAN

You will then see the load appear.


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[Lorens]

Thx for your reply!

I got the following error message when i used the Sbctran command

Selected areas attached to line 31 are not meshed. Surface load PRES on this line is not transferred. Loads will be transferred to meshed areas attached to this line.

 

[Drej]

And...?


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[Lorens]

I don't get any result, in the nodal or element solution, my conlcusion is that you must put pressue on a area not lines for solid elements, the problem is that i can't do that. (when i put it on a area it work but not when i put it on a line)

That is why i hope i have missed something ...

 

[meshparts]

Hi,

if your model is 3D, I can't imagine how you would apply pressure on lines: What direction, what area??

So is your model 3D or 2D?

Alex

 

[Drej]

The message:

"Selected areas attached to line 31 are not meshed. Surface load PRES on this line is not transferred. Loads will be transferred to meshed areas attached to this line."

just tells you that ANSYS cannot transfer the loads applied to the lines onto the mesh because you haven't meshed the model yet. This will not be the problem, since as soon as you mesh the model ANSYS automatically issues the SBCTRAN command internally anyway. You should mesh the model and then re-issue the SBCTRAN command? Then you issue SFELIST -- or similar -- to see the value of the loads you applied.

But I agree with you: I think you've missed something.


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[przemek]

Hello,
1. Use the command "SFL", but You must be sure that the line is a part of the meshed structure/wolume and must be meshed (conected with for example the volume mesh).

2. To deactivate certain elements for being listed or plotted is the command esel,u,,,123 (unselected the element number 123 for example)or esel,s,,,123,178 (to select elements from 123 to 178), also are usuful "nsel" comand (for the nodal solution) and others nsll, esll (to select the nodes and elements from just selected lines) or nsla, esla (from area) and nslv, eslv (from volume)