A quick flexibility and family table application for an o-ring.
Certainly not exceptionally comprehensive but easy to use if you must show multiple states of an o-ring on a drawing.
The challenge here was to make a rectangular shape round with flexible components. A revolve section sketch will not allow lines to go to zero length like some features allow. The second best choice was to add a round to a rectangular profile.
For this instance is an o-ring that has a defined groove of .125 x .093. The o-ring's free state sectional diameter is .125.
A perimeter value in a sketch is used to confirm, but not utilize the value of the resulting radii when the o-ring is squished. The required level of accuracy here is purely up to the user. In this case, I chose that the perimeter remains constant.
note: relations cannot be used with dimensions applied to flexible component tables.
The o-ring model was created in the squished state. This is purely a matter of choice as both affected dimensions are overwritten at the assembly level with family tables.
What makes this work is the ability to make a square profile fully round with the round feature.
Let me know if you have any questions.
Love that you share what you learn/know with our community.
I have dealt with this before but in a different way. Not at my Creo computer right now and not even sure I could find it but in case it is of use it went like this:
This overcomes the problem having a zero length segment while still giving a high level of control. You can do a simple compression such as clamping and you can simulate pressure distortion but only to the point of squaring a corner and not extruding a corner out into a gap as can happen.
Hope this helps.
Thanks Brent. I do this so I can find these tips later for myself Its a gray matter thing...
Good tip on using the conics. I have had to calculate deformation in relation to area rather than perimeter. I couldn't find a clean way to manage this either. A graph function (evalgraph) in the sketch relations comes to mind. That would reduce the 2 dimensions to 1 in the family table. Or better, use distance between the two surfaces. For applications more critical, it would be worth the extra effort to map a few points for a graph feature.
Now where did I put that document regarding evalgraph....