Free boundary condition in HHJ method for Kirchoff-love equation

NGSolve
1

Hi,
I want to solve the Kirchoff-love plate equation by using the HHJ method. For the clamped edges it’s work. But I want to solve with free boundary conditions on the right edge. It’s did not work. You can see this in the following attachment.

Best,
Rauf.
KL_transverse_load_sqaure geometry.ipynb (3.9 KB)

2

You need to set a Dirichlet condition in the HDivDiv space on the “right”. And you need to omit “right” from the Dirichlet condition in the H1 space.

p.s. I tried this and it gives a bad solution. When I use HHJ, I use a different weak formulation than what is given in your example (which looks copied from an example in NGSolve). So, perhaps, the boundary conditions are handled differently for this formulation. Joachim should be able to comment.

3

Thanks for the reply. You are right. By setting Dirichlet conditions in the HDivDiv space on the right. But by changing the solver sparsecholesky to umfpack. It give good solution. Michael told me about that. Anyhow, the problem is solved.
Thanks.
Best,
Rauf.