Apply Uniform Displacement BC for Multidomain

1

Hello everyone,

I want to apply thermal expansion of a volume that contains two sub-domain as shown in the figure. Since they have different expansion coefficient and free traction BC, they expands non-unifomly as expected. However, I want to apply a displacement BC which will force them for uniform displacement behavior as shown in bottom picture by enforcing zero axial force on that edge. Is there a way to define such a BC ? Thanks.

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If you want the displacement to be an unknown over the interface, but uniform, you can use my multi point extension for dolfinx. See for instance: dolfinx_mpc/demo_elasticity_disconnect.py at master · jorgensd/dolfinx_mpc · GitHub

3

Hi dokken,

Thanks for the link. Probably MPC definition will work properly as you suggested. However actually I do not use dolfinx yet and I do not want to migrate it in case there might reveal problems while working with some (legacy) functions in v2018 and v2019 dolfin codes.
Is it possible to enforce the following BC rather than using the MPC ?
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Probably an iteration loop requires for it.