Learning Forum

[Doug]

Hello Ansys Community!!!   A month ago I got help on how to print a ring in a cylinder without a force in the last step. I used a frictionless contact and applied a load moment to the transverse surfaces of the ring. Everything had worked great as you can see on the third picture.

 

 

   

 
Now I have to evaluate the contact pressure and the light gap. But in the contact tool I get strange results. Where the light gap is zero, there must be pressure (from the spring force of the ring). but in the contact tool the pressure is zero everywhere. That means the ring is only on the surface, although I did not use "Adjust to touch".

   

   
How can I run the simulation so that the ring at the end presses the cylinder wall?
I definitely need contact pressure and that can't be zero. That should follow the results of the light gap.   I tried the following:
* Contact changed from "No Ramping" to "Ramped effect"
* Change pinball radius
* Change to Pure penalty and Augmented Lagrange
* Change the Contact Stifness
* Change the Behavior to symmetric
But nothing worked
Please help me

[peteroznewman]

Please use File, Archive to save a .wbpz file and attach that after you post a reply.

[Doug]

Hi Peteroznewman,
Thank you for your answer! I am not allowed to upload the model here.
But I attached another model that presents the same problem.
You can also see in this model that the Part 2 is pressed in Part 1. The problem is that I cannot evaluate this pressure.
If I add a contact tool and add a gap and pressure, you notice that the representation of the gap makes sense, but the representation of the pressure unfortunately makes no sense.

I conclure that Part 1 simply touches Part 2 and does not press.

How can I solve this problem?

 
Thank you for your Help

[peteroznewman]

You did evaluate that pressure, here is the result in your archive. There is a pressure on each side wall.

There is no pressure on the bottom face because you used a Fixed Support. If you want to see the pressure on the bottom face, don't use a Fixed Support, use a Displacement support and turn that off in step 2 once some frictional contact is established on the side walls to hold the part in place.

[Doug]

Thanks for the answer.
Please just ignore the bottom face.
My problem is not to see the pressure on the bottom, but I want to know why I can't see the pressure on the complete sidewalls. (contact face)
According to the gap contact tool, the Side walls of the two parts touch each other. But why is there no pressure on the all side? how can I see (or apply) the contact pressure on the entire surface?

 

[peteroznewman]

Doug,

You put a Fixed Support on the top and bottom of the U shaped outer body.  The contact pressure, which is very high near the center, causes the outer leg to bow out in the middle.

That is why there is contact pressure at the middle and the top of the inner clip, because there is a bowed surface.

One change that would give a more uniform pressure is to remove the Fixed Support at the top of U outer piece.  Using more than 2 elements through the thickness of the inner piece might help, as would some changes to the Contact definition.