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Periodic Conditions
Posted Feb 15, 2012, 1:57 a.m. EST Geometry, Studies & Solvers, Structural Mechanics Version 4.2, Version 4.2a 3 Replies
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I'm trying to solve a problem with periodic boundary conditions. If I set periodic conditions with the type of continuity on a geometry of a cube, and then a prescribed displacement on a face, then the cube moves in space, but does not experience deformation because the displacement of 2 opposite faces is equal.
Does anyone know how i can set periodic conditions such that the the cube will experience deformation?
In the model library of Comsol there is an example of Floquet periodicity, but I haven't seen one of continuity...
Thanks
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for me it sounds like you have "antiperiodical" loads, but you want symmetry, no ?
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Good luck
Ivar
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U_right - U_left = (F - I ) *X
where F is the deformation gradient, U_left and U_right are the displacements of the left and right faces of the cube, I is the identity tensor and X is the distance between the faces.
However, i'm not sure of how to impose this condition...
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I believe that is what the "solid" physics "Periodic condition BC" imposes (the underlaying equation is slightly cryptic with "if" and "src & dst" names).
Then up to you to decide how many DoF you constrain, and how they are aligned w.r.t the global coordinate transform
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Good luck
Ivar