Creo Simulate - contact Interfaces Being Ignored

[JoeMartin]

Hello-  I'm looking for some guidance on an analysis that I setting up inside Creo Simulate.  I'm using some contact interfaces to allow rotation about a set of pins and it seems that Creo is ignoring these interfaces without warning, but it is evident in the results.  I've added a screen shot of the problem (see below).

Rotation is permissible between the red pins and the light blue parts (hence the use of contact interfaces).  With a load applied in the vertical direction (down) on the brown component, the gray actuator reacts this load and keeps it in position. This has a similar setup using contact interfaces but Creo seems to calculate this properly in the results.

Can anyone offer any insight on why Creo would be ignoring these interfaces?  Any solutions that would correct this?

[Chris3]

In the background the contacts interface is just adding springs between the components and it iteratively makes the springs stiffer until it converges on a solution.

I would suggest for this problem that you not use a contact interface and instead define your own spring (or beam) that has the degrees of freedom that you are looking to release.

[SweetPeasHub · Accepted solution]

I can think of some reasons for this, but there may be more.

1. Interface hierarchy - contact being overridden by a free interface that takes precedence.

2. Position changes so fast the contacts are missed (fix= use more load steps and smaller load so the movement is more gradual)

3. Press fit condition is being missed at analysis start.

4. The bars are sliding off the end of the pins because it does not have any contacts perpendicular to the axis to stop that movement direction.

5. Contacts are defined as planar only so cylinders not included.

6. too large elements at the contacts.

My guess is #4. You need contact for both the cylinders for the pin and the thrust bearing surfaces to keep it between the forks.