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How a fluid located between a conical cap and conical rod behaves when the cap is seated
Posted 9 apr 2011, 14:44 GMT-4 Fluid & Heat 1 Reply
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In dentistry we cement crowns to prepared teeth. The teeth have a conical shape and the inside of the crown we cement has the same shape as the prepared tooth. During cementation, the cement is placed inside the crown and the crown is then pressed down on the prepared tooth. During that process, most cement flows away from the crown and leaves a thin film. My intention is to mimic that process, and I wonder if anyone is familiar with a similar problem or have any suggestions how to solve that problem.
Sincerely
Karl-Johan Soderholm
Sincerely
Karl-Johan Soderholm
1 Reply Last Post 10 apr 2011, 05:45 GMT-4
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Posted:
1 decade ago
Hi
I would start in 2D-axi with 3 triangles (delete all objects in the r<0 region), overlapping to define the two solid regions and the thin interface of cement. Then define your materials, I'm not sure which model to use for your cement, it depends on which material parameters you have, probably an elasto-plastic material (all solid to begin with), later one might change the cement to a "fluid" if you consider that as more appropriate, a FSI model is then appropriate, but that is a 3 physics coupled model, it's tough and often frustrating to start at that level of complexity, it all depends on your previous COMSOL expertise.
fix the lower solid part at the bottom, and do a parametric scan of the upper solid bloc on the upper boundary, applying a Z direction load
Later when you are happy in 2D-axi model, you might want to go to 3D to have more representative shapes of the parts, as then you have debugged the material choice and settings.
If you are really considering large deformation in the cement, you might need to use the ALE meshing for this part. For simplicity I would start without, one can always add it as a second step.
Do not forget that 2D-axi means in fact operating in 3D but in a cut view, and that a Point in 2D-axi is a line (loop line of length 2*pi*r) and an Edge is a surface and a surface is in fact a volume (use correctly the 2*pi*r multiplier, check carefully the units)
--
Good luck
Ivar
I would start in 2D-axi with 3 triangles (delete all objects in the r<0 region), overlapping to define the two solid regions and the thin interface of cement. Then define your materials, I'm not sure which model to use for your cement, it depends on which material parameters you have, probably an elasto-plastic material (all solid to begin with), later one might change the cement to a "fluid" if you consider that as more appropriate, a FSI model is then appropriate, but that is a 3 physics coupled model, it's tough and often frustrating to start at that level of complexity, it all depends on your previous COMSOL expertise.
fix the lower solid part at the bottom, and do a parametric scan of the upper solid bloc on the upper boundary, applying a Z direction load
Later when you are happy in 2D-axi model, you might want to go to 3D to have more representative shapes of the parts, as then you have debugged the material choice and settings.
If you are really considering large deformation in the cement, you might need to use the ALE meshing for this part. For simplicity I would start without, one can always add it as a second step.
Do not forget that 2D-axi means in fact operating in 3D but in a cut view, and that a Point in 2D-axi is a line (loop line of length 2*pi*r) and an Edge is a surface and a surface is in fact a volume (use correctly the 2*pi*r multiplier, check carefully the units)
--
Good luck
Ivar