Coupled poroelastic-elastic problem

[Мария Бронзова]

Dear All,

I have been working with acoustic porous media and would like to extend my script to deal with two-layered acoustic absorbers, in this case I am interested in adding an elastic layer on top of my porous media.

I took the step-46 as an example for matching two physical domains, everything works fine, apart from the interface boundary condition. In my case I need to strongly enforce the continuity of the solid displacement vector. In other words I need to set the solid displacements on the poro-elastic interface equal to the displacements of the poroelastic media on the same interface.

Would you please give me a hint on how it can be best done? Would the "constraints.add_line" function be still any help in this case? 

Thank you a lot!

Kind regards,

Mariia 

[Wolfgang Bangerth]

On 2/17/22 01:50, Мария Бронзова wrote:
>
> I took the step-46 as an example for matching two physical domains, everything
> works fine, apart from the interface boundary condition. In my case I need to
> strongly enforce the continuity of the solid displacement vector. In other
> words I need to set the solid displacements on the poro-elastic interface
> equal to the displacements of the poroelastic media on the same interface.
>
> Would you please give me a hint on how it can be best done? Would the
> "constraints.add_line" function be still any help in this case?

That's one way. If you can identify which elastic degrees of freedom need to
match which poro-elastic degrees of freedom, then you can add continuity as a
constraint.

The alternative is to weakly enforce continuity of displacements in the same
way as DG formulations do, or as the Nitsche method does for boundary
conditions. This may be the easier approach, in particular if the finite
element spaces you use on both sides of the interface don't match.

Best
W.


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Wolfgang Bangerth email: bang...@colostate.edu
www: http://www.math.colostate.edu/~bangerth/