#26 2020-10-22 10:34:33

mib

Member

Registered: 2019-11-10

Posts: 88

Re: Advice needed on <EXCEPTION> <DVP_1> (DYNA_NON_LINE)

Could you please explain the reason why slave surface mesh has to be finer then that of master?

maybe this

code-aster.org/doc/default/en/man_u/u2/u2.04.04.pdf (copy and paste in your browser)

from 2.2.3 Case general

to 2.2.7 Quality of the grid

Last edited by mib (2020-10-22 10:37:31)

hkboondoggle

Member

Registered: 2020-05-29

Posts: 27

Re: Advice needed on <EXCEPTION> <DVP_1> (DYNA_NON_LINE)

It is converging, do below.

Make Sphere (ball)Mesh Fine.
Reduce Time Step to 100

Sammer, how small was the ball mesh size in your setting?
I ended up using this setting:
[ball = 0.1; substrate = 2.5] & number of time steps = 100

But even with this master-to-slave mesh size ratio in 1:2.5, it still gave out convergence issue.
I have attached the log of this latest trial FYI.
In which there was a multiple occasion of <A> <COMPOR2_9> occurred:

!-----------------------------------------------------------------!
   ! <A> <COMPOR2_9>                                                 !
   !                                                                 !
   ! Les déformations deviennent trop grandes : <6.382117E-02>       !
   ! => GROT_GDEP sous COMPORTEMENT n'est plus valide.               !
   !                                                                 !
   ! Pour un calcul en                                               !
   ! grandes déformations                                            !
   ! il faut utiliser GDEF_LOG ou SIMO_MIEHE.                        !
   !                                                                 !
   ! Pour un calcul hyper-élastique, utiliser ELAS_HYPER.            !
   !                                                                 !
   !                                                                 !
   ! This is a warning. If you do not understand the meaning of this !
   !  warning, you can obtain unexpected results!                    !
   !-----------------------------------------------------------------!

Is it something related to the convergence issue?

I am unable to test further shrinking the ball mesh size for the time being, as somehow Salome-Meca is giving out fatal error whenever loading up the mesh of all previous case files:

Any suggestions other than re-installing Salome-Meca?

maybe this

code-aster.org/doc/default/en/man_u/u2/u2.04.04.pdf (copy and paste in your browser)

from 2.2.3 Case general

to 2.2.7 Quality of the grid

Thanks for the info Mib.
So I suppose this is a hard-coded limitation of CA?
Then this is not a good news for me, because the physics in my case study includes deformation mechanism & local strain hardening effect at the ball / substrate under the same length order.
Are you suggesting that I should look for other simulation tools instead?

---

Attachments:
stderr_command_salome.log, Size: 154.22 KiB, Downloads: 184

sameer21101970

Banned

Registered: 2019-09-06

Posts: 354

Re: Advice needed on <EXCEPTION> <DVP_1> (DYNA_NON_LINE)

Does your system  have Graphic Card.

You need to download sm2019 or use CA 14.4 or now 14.6

You are using Windows version, i am using Linux version.
It is better to do Partition of HardDisk, Download Lubuntu 18.04, Sm2019 Linux Version.

Windows, i am not using because of unexpected errors, as you are getting.

refer salome meca installation forum, installation procedure given.

Last edited by sameer21101970 (2020-11-05 08:52:57)

konyaro

Member

From: Genève

Registered: 2016-04-02

Posts: 270

Re: Advice needed on <EXCEPTION> <DVP_1> (DYNA_NON_LINE)

Hello,
it is possible to simulate the beginning of the crash of your ball on the plate with Code_Aster but once the distortion of elements gets too high the simulation will stop. You should investigate other ways:

1) Use of linear tetrahedrons can help but it won't be enough anyway.
2) Adaptive meshing would be an option but doesn't exist in Code_Aster. Homard can refine a mesh but not remesh a deformed mesh. Different commercial software handle it.
3) An explicit solver is a good option but I don't know any good opensource ones.
4) SPH could be an option with good opensource codes.

Konyaro

---

失敗は成功のもと (L'échec est la base de la réussite)

sameer21101970

Banned

Registered: 2019-09-06

Posts: 354

Re: Advice needed on <EXCEPTION> <DVP_1> (DYNA_NON_LINE)

spheric-sph.org/sph-projects-and-codes

above link for SPH will be helpful.