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How to set boundary conditions for two parts that are in contact on one boundary but free to move?

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Hi,

i have a problem with my boundary conditions. The attached file shows a simple overview. The blue part is material 1 and can be deformed. The orange part is material 2 and like a pellet that lies insind the blue part. The yellow circle shows the contact boundary. I tried:

1. contact pair, but the master and slave boundary are the same?
2. "roller", but physically not true, it can move to it's normal position. E.g. if the blue parts deforms, it builds with the orange part a V-notch. Think about it if you press down the upper right corner of the blue part.
3. it's no other contraint condition true

In words: this boundary is free to move to all dimentions, but the contact area can change. It could be the full length or just one point (depending on the deformed shape of the blue part)

Regards


1 Reply Last Post Jul 21, 2010, 4:20 a.m. EDT
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago Jul 21, 2010, 4:20 a.m. EDT
Hi

two parts that are in contact like that need, for me:
- some kind of force (gravity ?) holding them together, or pushing one agains the other, and
- as you say a contact link saying that the surfaces may deforme independently but still have some topological interaction

To get the contact running you must use "assembly mode", but you should redice your geometry to two items of composite geometry type. Then you can define the conatact boundary, and use a resonnably fine mesh (not just 3 points). Ther are differnt methods for contact simulations, this has been discussed several times, check the forum, as convergence is sometimes delicate

--
Good luck
Ivar
Hi two parts that are in contact like that need, for me: - some kind of force (gravity ?) holding them together, or pushing one agains the other, and - as you say a contact link saying that the surfaces may deforme independently but still have some topological interaction To get the contact running you must use "assembly mode", but you should redice your geometry to two items of composite geometry type. Then you can define the conatact boundary, and use a resonnably fine mesh (not just 3 points). Ther are differnt methods for contact simulations, this has been discussed several times, check the forum, as convergence is sometimes delicate -- Good luck Ivar

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