Elmer Discussion Forum

For the HelmHoltz Structure case https://github.com/ElmerCSC/elmerfem/tree/devel/fem/tests/HelmholtzStructure I test a beam in fluid, 2D, the frequency should be 81 Hz in air with fluid properties of air the frequency is 84.9 Hz with fluid properties of water the frequency is 84.9 Hz, it should be l...

I put a load on it so that there would be a solution. Then I ran it with and with out the pre strain. There was no change in the answer.

I redid the transient damping test with displacement BC instead of load force, and the results look reasonable. it vibrates after being let go.

It looks like progress. The most help is available if you can post a complete case, sif and mesh. And ask questions around that. I use github to post mine.

Not necessarily a related case, but an example of a github repository

https://github.com/mrkearden/harmonic_response

I would have to test if doing by restart allows you to change boundary conditions. Otherwise there are conditional boundary conditions Displacement 1 = Real 0.0 Displacement 1 Condition = Real $condx When $condx > 0, the condition is enforced, when $condx < 0, not So perhaps Displacement 1 = Real 0....

You may be interested in this thread
viewtopic.php?t=7833&hilit=speaker

Chapter 3 https://www.nic.funet.fi/pub/sci/physics/elmer/doc/ElmerSolverManual.pdf You have to tell Elmer to save the restart file in the first analysis. I have done this with transient, in 1 solution, have not tried it in restart. In transient I apply the load for x amount of time, then let it go. ...

I do not believe this is the calculation of the eigenvalues of the structure in fluid, which seems to be what your are looking for.

There are three test cases named levelset

https://github.com/ElmerCSC/elmerfem/tr ... /fem/tests