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#2 Salome-Meca usage » Mesh display in paravis » 2022-06-25 10:57:24

jacob
Replies: 0

Hello,
why paravis displays the mesh weirdly when rotating? Is there a way how to avoid this?

Thanks

#3 Re: Code_Aster usage » calculate material properies » 2022-06-24 15:47:10

I know about IMPR_CONCEPT, but it does not give me E, density etc.

#4 Code_Aster usage » calculate material properies » 2022-06-09 21:20:58

jacob
Replies: 2

Hello, is there a command for calculating material properties and displaying it in paravis? For example, E, mu, yield strength, shell thickness etc.

Thanks

#5 Code_Aster usage » problem with spring preload » 2022-06-09 14:14:06

jacob
Replies: 0

Hello,
could somebody help me with this kind of error message?

Thank you

! <S> Exception user raised but not interceptee.                           !
   ! The bases are fermees.                                                   !
   ! Type of the exception: error                                             !
   !                                                                          !
   ! Problem in the computation of option FORC_NODA / REAC_NODA:              !
   !                                                                          !
   ! The number of subpoint of the stress field contained in the SD is        !
   ! not                                                                      !
   !  coherent with what was defined in AFFE_CARA_ELEM.                       !
   !                                                                          !
   ! It is probable that the stress field was extracted on only one subpoint. !
   !                                                                          !
   !                                                                          !
   ! It is imperative to use a complete stress field for the computation of   !
   ! FORC_NODA.                                                               !
   !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
fine CR of execution of JDC in MIXTE

#6 Re: Code_Aster usage » The best way how to do bolt preload? » 2022-05-11 12:34:02

Well, I don't think that there must be a problem if the difference between your applied and relaxed bolt stress is very high (even 50%). It just means that the flanges are not that stiff.

#7 Re: Code_Aster usage » The best way how to do bolt preload? » 2022-05-11 08:14:28

Hello,

Maggoo, the link says: This post cannot be displayed.

I have seen many methods how to do preload but the main problem with many methods is, that some of the initial stress is lost, so you have to input some value higher which you initially do not know.

With "my method" you don't have to iterate, and it behaves quite nicely. You can even see how the bolt is tightened with time (0 to 1 s ).

#8 Re: Code_Aster usage » The best way how to do bolt preload? » 2022-05-09 07:27:37

I think this similar method is even better.
The nut is actually pushed through the bolt like it is done in reality, and then it is locked. No slice in the middle.

#9 Code_Aster usage » The best way how to do bolt preload? » 2022-05-09 07:17:04

jacob
Replies: 7

Hello,
I would like to ask if somebody is familiar with a solution I propose. I know that there are many methods how to model pretension.

For example:
You can prescribe temperature and cool the bolts down.

Or prescribe initial deformation in the middle elements, but then you have negative strain in the middle which is physically nonsense.

Similar it is with initial stress.

Then you can use some initial clearance, but every time you want to change the preload you have to remesh.

However, all these method require some trial and error to achieve desired pretension.


For example ansys or nastran (at least I think) models bolt pretension this way:
It cuts the bolt in the middle, then applies desired force on both sliced sides with constraints in other two directions than is the force direction, and then it solves the problem. In the next step, it "locks" the bolt (adds the equation in third direction) and solves with additional loads.
This method is also applicable for beams.

I did something similar in CA and I think it works.

#10 Re: Salome-Meca installation » Salome Meca 2021 on Windows » 2022-04-12 11:22:45

I guess you forgot to install also Code_Aster 2021 for windows.

#11 Re: Salome-Meca usage » rbe2 and rbe3 / MPC / joints » 2022-04-05 19:22:05

Well if you look just on comm, the last one is important.
__________________________________________________
##LIAISON_SOLIDE


mesh = LIRE_MAILLAGE(UNITE=2)

model = AFFE_MODELE(AFFE=(_F(MODELISATION=('3D', ),
                             PHENOMENE='MECANIQUE',
                             TOUT='OUI'),
                          _F(GROUP_MA=('0d', ),
                             MODELISATION=('DIS_TR', ),
                             PHENOMENE='MECANIQUE')),
                    MAILLAGE=mesh)

elempro0 = AFFE_CARA_ELEM(DISCRET=_F(CARA='K_TR_D_N',
                                     GROUP_MA=('0d', ),
                                     VALE=(1.0, 1.0, 1.0, 1.0, 1.0, 1.0)),
                          MODELE=model)

mater = DEFI_MATERIAU(ELAS=_F(E=200000.0,
                              NU=0.3))

fieldmat = AFFE_MATERIAU(AFFE=_F(MATER=(mater, ),
                                 TOUT='OUI'),
                         MODELE=model)

load = AFFE_CHAR_MECA(DDL_IMPO=(_F(GROUP_MA=('fix', ),
                                   LIAISON='ENCASTRE'),
                                _F(DX=0.0,
                                   DY=0.0,
                                   DZ=0.0,
                                   GROUP_NO=('node', ))),
                      LIAISON_SOLIDE=_F(GROUP_NO=('hinge', 'node')),
                      MODELE=model,
                      PRES_REP=_F(GROUP_MA=('press', ),
                                  PRES=10.0))

reslin = MECA_STATIQUE(CARA_ELEM=elempro0,
                       CHAM_MATER=fieldmat,
                       EXCIT=_F(CHARGE=load),
                       MODELE=model)

reslin = CALC_CHAMP(reuse=reslin,
                    CRITERES=('SIEQ_ELGA', 'SIEQ_ELNO', 'SIEQ_NOEU'),
                    RESULTAT=reslin)

IMPR_RESU(RESU=_F(RESULTAT=reslin),
          UNITE=3)

____________________________________________________

##LIAISON_RBE3


mesh = LIRE_MAILLAGE(UNITE=2)

model = AFFE_MODELE(AFFE=(_F(MODELISATION=('3D', ),
                             PHENOMENE='MECANIQUE',
                             TOUT='OUI'),
                          _F(GROUP_MA=('0d', ),
                             MODELISATION=('DIS_TR', ),
                             PHENOMENE='MECANIQUE')),
                    MAILLAGE=mesh)

elempro0 = AFFE_CARA_ELEM(DISCRET=_F(CARA='K_TR_D_N',
                                     GROUP_MA=('0d', ),
                                     VALE=(1.0, 1.0, 1.0, 1.0, 1.0, 1.0)),
                          MODELE=model)

mater = DEFI_MATERIAU(ELAS=_F(E=200000.0,
                              NU=0.3))

fieldmat = AFFE_MATERIAU(AFFE=_F(MATER=(mater, ),
                                 TOUT='OUI'),
                         MODELE=model)

load = AFFE_CHAR_MECA(DDL_IMPO=(_F(GROUP_MA=('fix', ),
                                   LIAISON='ENCASTRE'),
                                _F(DX=0.0,
                                   DY=0.0,
                                   DZ=0.0,
                                   GROUP_NO=('node', ))),
                      LIAISON_RBE3=_F(COEF_ESCL=(1.0, ),
                                      DDL_ESCL=('DX-DY-DZ', ),
                                      DDL_MAIT=('DX', 'DY', 'DZ'),
                                      GROUP_NO_ESCL=('hinge', ),
                                      GROUP_NO_MAIT=('node', )),
                      MODELE=model,
                      PRES_REP=_F(GROUP_MA=('press', ),
                                  PRES=10.0))

reslin = MECA_STATIQUE(CARA_ELEM=elempro0,
                       CHAM_MATER=fieldmat,
                       EXCIT=_F(CHARGE=load),
                       MODELE=model)

reslin = CALC_CHAMP(reuse=reslin,
                    CRITERES=('SIEQ_ELGA', 'SIEQ_ELNO', 'SIEQ_NOEU'),
                    RESULTAT=reslin)

IMPR_RESU(RESU=_F(RESULTAT=reslin),
          UNITE=3)

#12 Re: Salome-Meca usage » rbe2 and rbe3 / MPC / joints » 2022-04-05 13:27:06

So if I managed to do RBE3 like that I should rather use K_TR_D_L?

If I understood it correctly I guess it is wrong when used for joint but since it is just connection to the ground it is ok. In my case it should be ok.
Am I wrong?

#13 Re: Salome-Meca usage » rbe2 and rbe3 / MPC / joints » 2022-04-05 12:44:02

Alright I managed to do that as you said and it works.

Thank you.

I also tried using K_TR_D_N (it seams more appropriate, so I don't have to use line element) and I guess it works.

#14 Re: Salome-Meca usage » rbe2 and rbe3 / MPC / joints » 2022-04-05 10:05:50

What I am trying to do is this.

So it has to be modelled as you are saying, I have to use spring? I cannot just constraint DX DY DZ (leave rotations free) at master node and couple it with nodes on left face using LIAISON_RBE3 or SOLID?

#15 Re: Salome-Meca usage » Where is AsterStudy module ? » 2022-04-04 19:12:16

Windows version is much easier to install however there is not all the functionality and it is not official.

#16 Re: Salome-Meca usage » rbe2 and rbe3 / MPC / joints » 2022-04-04 17:23:03

Sorry I forgot to mention the file is hdf with AS, now hinge_beam_AS.hdf. The other hdf is for the mesh. I am using latest salome for the mesh but salomemeca2018 for solving.

#17 Salome-Meca usage » rbe2 and rbe3 / MPC / joints » 2022-04-04 14:26:41

jacob
Replies: 11

Hello,
what is the correct way to create hinge (or any other constraint) using rbe2 or rbe3 in salome meca?

I tried LIAISON_DDL and LIAISON_RBE3 but I haven't found a way how to use it on simple solid.
I also read there is a way how to do it using springs where one could define local coordinate system, but I guess I would spent hours trying.

#18 Re: Salome-Meca usage » Where is AsterStudy module ? » 2022-04-04 12:19:52

Salome is just pre and post processor without solver code_aster.

#19 Re: Salome-Meca usage » select body/surface in paravis » 2022-04-04 07:03:57

Yeah I realized later. But thanks anyway.

#20 Re: Salome-Meca usage » select body/surface in paravis » 2022-04-03 22:19:12

I tried that but it also does not work.

#21 Re: Salome-Meca usage » select body/surface in paravis » 2022-04-02 13:09:22

I tried it on Salome Meca 2021 on Xubuntu but it behaves the same. Only volume works.

#22 Re: Salome-Meca usage » reactions from stage 2 » 2022-04-02 13:07:43

I finally tried it on Salome Meca 2021 on Xubuntu and it works normally. I guess problem is with windows version.

#23 Re: Salome-Meca usage » select body/surface in paravis » 2022-03-30 19:45:13

hmm on volme it works, but not on the surfaces.
However I have to prepare everything before solving I guess?

#24 Re: Salome-Meca usage » select body/surface in paravis » 2022-03-30 08:34:05

Yes I tried that before I posted, but it does not show anything. I tried many models.

#25 Salome-Meca usage » select body/surface in paravis » 2022-03-29 21:10:59

jacob
Replies: 12

Hello,
lets say I have done static study on an assembly. How do I show results only on some parts or surfaces?
(I mean automatically, not manually selecting cells and then extract selection. It is not possible on something complex)

Thanks