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Shrinkage modelisation
Posted Sep 12, 2018, 12:23 p.m. EDT Structural & Acoustics, Heat Transfer & Phase Change, Structural Mechanics Version 5.3a 1 Reply
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Dear all,
I have a question regarding the setting the cast of polymer molding in Comsol. I want to simulate the shrinkage process of a plastic part in a mold, during which volumetric shrinkage happens due to the drop of temperature.
Is there a way in Comsol to set this modelisation taking into account the shrinkage effect and the disband that occurs between the casted part and the mold?
BTW, I am using both structural mechanics and heat transfer module and hoping to simulate the final shape (displacement and temperature field). I used "contact pairs" to model the contact and the Multiphysics "Thermal Expansion" and "Temperature Coupling" (Thermo-elasticity) and I’m getting convergence problems. I tried already to refine the mesh on the contact boundaries with no success.
It seems that when the disband between the mold and the casted part occurs, the nonlinear solver does not converge.
Thanks in advance!
Best regards,
Moaine
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Hi Moaine,
A probable reason is that when the molded part loses contact with the model, it will have too few constraints to prevent rigid body motions. One method so treat such problems is to add weak springs to the part.
Another possible solution (with some physical appeal) is to add gravity to your model. Then the molded part would be forced to rest on the mold and not float free in space.
Regards,
Henrik
Henrik Sönnerlind
COMSOL