Search found 231 matches
- Today, 13:21
- Forum: ElmerSolver
- Topic: Helmholtz BC vs. Acoustics BC
- Replies: 1
- Views: 20
Re: Helmholtz BC vs. Acoustics BC
Suitable BCs are explained in Section 13.2.2 of the documentation https://www.nic.funet.fi/pub/sci/physics/elmer/doc/ElmerModelsManual.pdf as "For example, outgoing waves may be approximated by setting Z = −rho_0 c and ZT = −iω/c on the outflow boundary". That is, one has to give also an im...
- 04 Mar 2024, 11:49
- Forum: ElmerSolver
- Topic: UMAT and mortar BC
- Replies: 6
- Views: 300
Re: UMAT and mortar BC
Thanks, your changes have now been merged. I noticed a small mistake in a size specification of memory allocation. It is also fixed in the devel branch.
-- Mika
-- Mika
- 09 Feb 2024, 12:37
- Forum: ElmerSolver
- Topic: UMAT and mortar BC
- Replies: 6
- Views: 300
Re: UMAT and mortar BC
Hi,
I think you have done right code modifications to allow for a normal-tangential BC with UMAT. They might well be worth creating a pull request.
-- Mika
I think you have done right code modifications to allow for a normal-tangential BC with UMAT. They might well be worth creating a pull request.
-- Mika
- 30 Nov 2023, 12:59
- Forum: General
- Topic: 1D beam modelling
- Replies: 38
- Views: 3457
Re: 1D beam modelling
I made a small change to the devel branch so that mass-proportional damping (Rayleigh Damping Alpha) for translational motions can now be given for the beam solver, whereas giving Rayleigh Damping Beta = ... causes a warning message.
- 29 Nov 2023, 18:18
- Forum: General
- Topic: 1D beam modelling
- Replies: 38
- Views: 3457
Re: 1D beam modelling
The beam solver doesn't yet understand the Rayleigh damping parameters, but adding the Rayleigh damping would be an easy modification
- 29 Nov 2023, 15:27
- Forum: General
- Topic: 1D beam modelling
- Replies: 38
- Views: 3457
Re: 1D beam modelling
Both these cases are free vibrations and were supposed to vibrate forever with a magnitude of the initial displacement as there was no damping First, it might be good to mention that while this is expected for an analytic solution, computational time integration methods often have numerical damping...
- 22 Nov 2023, 13:16
- Forum: General
- Topic: 1D beam modelling
- Replies: 38
- Views: 3457
Re: 1D beam modelling
As another test, I now checked that if the initial deflection is such that the displacement component U 2 depends linearly on the coordinate X in the absense of external loads, U 2 at the free end starts to oscillate like this end-u2.png Probably a refined mesh would be needed, so that all eigenmode...
- 22 Nov 2023, 11:20
- Forum: General
- Topic: 1D beam modelling
- Replies: 38
- Views: 3457
Re: 1D beam modelling
There seems to be a problem that the beam solver has not automatically set the order of time derivatives. Therefore one has needed an explicit command Time Derivative Order = 2 in the sif file. I however updated the code as https://github.com/ElmerCSC/elmerfem/commit/7fe6d9b916d272db36f02019b202aa2c...
- 10 Nov 2023, 16:01
- Forum: ElmerPost
- Topic: Compute or store the CRS matrices
- Replies: 11
- Views: 1383
Re: Compute or store the CRS matrices
I would like to learn how to extract the CRS matrices You might try to use the ready subroutine SaveLinearSystem contained in the file SolverUtils.F90. For example, you could try to add the following lines to the solver section linear system save = true linear system save slot = assembly so that th...
- 11 Sep 2023, 11:05
- Forum: Software development
- Topic: Edge Element Matrices / Microwave Examples
- Replies: 2
- Views: 559
Re: Edge Element Matrices / Microwave Examples
A rather simple example of coding a solver which uses H(curl)-conforming finite elements could be https://github.com/ElmerCSC/elmerfem/blob/devel/fem/tests/SecondOrderEdgeElement2D_BCs/EdgeFEInterpolationTest.F90 In a special case (Material Param = Real 0.0) it assembles just the mass matrix. Howeve...