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modelling a vertically moving plate with free horizontal rotation

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May I ask someone to advise me how would I model a rectangual plate with prescribed vertical translational motion capable of free rotation along horizontal plane.
Plz see the image attached.
Any help would be greatly appreciated.


2 Replies Last Post 27 ago 2015, 02:24 GMT-4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 9 years ago 27 ago 2015, 02:01 GMT-4
Hi

I see a few ways but it depends on what else you want to do and the surrounding of your model:

If we consider ONLY the plate as is, one can

a) put oneself in the "rotating" reference plane and apply "roller" conditions to the 4 edges,
Any centrifugal forces can be applied by adding a body load in cylindrical coordinates, but one needs an equation for the rotating velocity

b) if the model accepts that the side edges are perfectly RIGID (but really 100% rigid, and with no thermal expansion ... still a valid assumption) then you could joins all side edges with a "Rigid Domain" BC and constrain the X,Y displacements of the CoR, and leave the Z and Theta free

c) if the centre of the plate is on a shaft with ball bearings with a cylindrical hole, one can constrain that cylinder wall with a "roller" BC

The latter is probably easier to combine with other physics

--
Good luck
Ivar
Hi I see a few ways but it depends on what else you want to do and the surrounding of your model: If we consider ONLY the plate as is, one can a) put oneself in the "rotating" reference plane and apply "roller" conditions to the 4 edges, Any centrifugal forces can be applied by adding a body load in cylindrical coordinates, but one needs an equation for the rotating velocity b) if the model accepts that the side edges are perfectly RIGID (but really 100% rigid, and with no thermal expansion ... still a valid assumption) then you could joins all side edges with a "Rigid Domain" BC and constrain the X,Y displacements of the CoR, and leave the Z and Theta free c) if the centre of the plate is on a shaft with ball bearings with a cylindrical hole, one can constrain that cylinder wall with a "roller" BC The latter is probably easier to combine with other physics -- Good luck Ivar

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Posted: 9 years ago 27 ago 2015, 02:24 GMT-4
Dear Dr Ivar
Thank you so much.
I will follow them and report here.
Actually this assembly is vibrating up and down sinoidally in fluid and allowed to rotate freely.
I am trying with 3d FSI hope the option c) seems to be more suitable.
Thank you so much
With regards
Dear Dr Ivar Thank you so much. I will follow them and report here. Actually this assembly is vibrating up and down sinoidally in fluid and allowed to rotate freely. I am trying with 3d FSI hope the option c) seems to be more suitable. Thank you so much With regards

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