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Clamped boundary condition for 2D model

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I have problem making Clamped boundary condition for 2D model. In fact, there is “Fixed constraint” which restricts movement in U and V (or X and Y) directions. But there is a need to eliminate rotation around Z axes. I rectangle subjected to heat expansion and selected the upper and lower horizontal edges subjected to “Fixed constraint”. The main problem is with unrealistically large deformation at both ends. It seems that not limiting the mentioned rotation may be the reason for this even out of plane!! deformation. I got better results using finer mesh. But still there is severely deformation at both ends. I would appreciate if you give me some advises in this regard.

2 Replies Last Post 16.11.2016, 10:00 GMT-5
Jeff Hiller COMSOL Employee

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Posted: 8 years ago 16.11.2016, 09:44 GMT-5
Hello Reza,
In a 2D solid structural analysis, rotations are not degrees of freedom, only displacements. That is why you cannot impose zero rotation at a point. What you can do is impose a fixed constraint to a point and a roller condition to a segment (or fixed constraint to one point and roller at another point, etc).
Best,
Jeff
Hello Reza, In a 2D solid structural analysis, rotations are not degrees of freedom, only displacements. That is why you cannot impose zero rotation at a point. What you can do is impose a fixed constraint to a point and a roller condition to a segment (or fixed constraint to one point and roller at another point, etc). Best, Jeff

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Posted: 8 years ago 16.11.2016, 10:00 GMT-5
Thank you Jeff. I used fixed constraint to a point and a roller condition to a segment and the deformation seems to be logical.
Thank you Jeff. I used fixed constraint to a point and a roller condition to a segment and the deformation seems to be logical.

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