I understood,

I'll study and comment again on the post. I believe that it actually has several nodes, because I don't know how to deal with the elements of the set and the connections they would have due to the analysis I would like to do, which is precisely to mix elements that suffer axial forces with elements that suffer bending moments.

Do I need to create a connection between these points? For Code_Aster to share these efforts?

Hi Helio, thanks for the reply.

Like you, I'm also Brazilian.

For sure. The only difference is that I would go from having a 1D model to having a 2D model. It is a very simple structure, there would be no computational difference. The idea was actually to find out if there's a way to do it even in a 1D element model. I will keep searching.

And as you mentioned, I would be able to assign the properties of the beams to the surface contours.
(I would have a mixed model in that case).

But, I think the biggest problem I'm facing is the boundary conditions for each bar in my structure. In SAP 2000 you can say that such element is or is not influenced by bending moments (truss frame elements - a structural element that is designed to support only axial forces - and gantry frame elements). This detail is crucial to my study... Do you know how this is done?

EDIT1: U3.11.01: "Modeling BAR treat only the efforts and axial deformations."
Could this be the way?

Hi tpa,

Yea,

The big question now is that the results are not consistent. It is a simple case where I did the analytical calculation and found a 39 mm displacement. For some reason I can't reproduce the case in Code_Aster and I don't know exactly where the errors are. I attached the case and the mesh. The dimensions are in millimeters (L 6500, D 219.08 and EP is 12.7) and the applied force in the length of 3000 mm in the center of the tube is 7 tol. If you can help, or anyone who reads this post.

The DOF that I used analytically (and in this case it was a 2D analysis) was to use one end as Fixed and the other with Roll. One of the issues is that in the real case the weight is supported on a support by the extremities, being able to move on the L axis.

Another very important issue is the fact that I want to do the linear analysis first, although I believe that this type of analysis, due to displacement, is a non-linear analysis, right?

Maybe FORCE_POTRE is the solution.

I'm also interested in whether there has been progress...

Konyaro,

See the result of the analysis in both software. Of course there is no better... far from it, but the results presented by Code_Aster, to my understanding, are inferior and maybe, I'm not sure, could be the responsibility of the boundary condition, what do you think?

EDIT1: I also attached the .mess file.

Hi,

I tried to reproduce what I had done in the bar, and it had worked, in the shaft.
Unfortunately, a series of errors appeared... which I understood to be from the mesh, but which I honestly don't think was badly done.

Because the mesh file is large, I put it in Google Drive: https:// drive.google.com/open?id=1acwcKCu2r4Ydmug13LB8A4NtzHJ6hYwP (Fixed region = Bearing)

The .mess and .comm files are then attached.
Who can help, I would be very grateful.

Hi Konyaro,

I can't attach to the forum because the vast majority of times I've tried 'very large file size' errors.

About the modifications you made, fortunately I was able to access the .comm file, but unfortunately the .med file could not be accessed, it presented error when I tried to import it.
So I can understand the changes that were made to the case, but I can't see the changes made to the mesh.
EDIT1: I was able to imitate your steps in my case. The results are somewhat distant from those presented in SimScale (where the idea of reproducing them came from), especially when the deformation is analyzed (SimScale max_D: 0.000096m; Aster_Study max_D: 0.001665). However, positive since I managed to run the case.

Did you even analyze my shaft case?

Can anybody help me?

Yes, I know.
I'm just trying to reproduce what I did in commercial software, and the problem, I believe, is precisely trying to reproduce the condition of Remote Displacement (I'll leave this image out of curiosity: encurtador.com.br/lmC23 - pay attention to 6 DOF). Or is it the condition of symmetry?

Yes, on the node I created I added the condition of DIS_TR (6 DOF), but apparently something is wrong. And I made that node not 'orphaned' but in the center of the face.

DEBUT(LANG='EN')

mesh = LIRE_MAILLAGE(FORMAT='MED',
                     UNITE=2)

mesh0 = CREA_MAILLAGE(CREA_POI1=_F(GROUP_NO=('Node', ),
                                   NOM_GROUP_MA=('Node', )),
                      MAILLAGE=mesh)

model = AFFE_MODELE(AFFE=(_F(MODELISATION=('3D', ),
                             PHENOMENE='MECANIQUE',
                             TOUT='OUI'),
                          _F(GROUP_MA=('Node', ),
                             MODELISATION=('DIS_TR', ),
                             PHENOMENE='MECANIQUE')),
                    MAILLAGE=mesh0)

mater = DEFI_MATERIAU(ECRO_LINE=_F(D_SIGM_EPSI=0.0,
                                   SY=579.0),
                      ELAS=_F(E=210000.0,
                              NU=0.3,
                              RHO=7.85e-06))

fieldmat = AFFE_MATERIAU(AFFE=_F(MATER=(mater, ),
                                 TOUT='OUI'),
                         MAILLAGE=mesh0)

Load = AFFE_CHAR_MECA(FORCE_FACE=_F(FY=18392.0,
                                    GROUP_MA=('Force', )),
                      MODELE=model)

g = AFFE_CHAR_MECA(MODELE=model,
                   PESANTEUR=_F(DIRECTION=(0.0, 0.0, -1.0),
                                GRAVITE=9.8066,
                                GROUP_MA=('Eixo', )))

Symmetry = AFFE_CHAR_MECA(DDL_IMPO=_F(DX=0.0,
                                      GROUP_MA=('Symmetry', )),
                          MODELE=model)

Remote = AFFE_CHAR_MECA(LIAISON_RBE3=_F(COEF_ESCL=(1.0, ),
                                        DDL_ESCL=('DX-DY-DZ-DRY-DRZ', ),
                                        DDL_MAIT=('DX', 'DY', 'DZ', 'DRY', 'DRZ'),
                                        GROUP_NO_ESCL=('Remote', ),
                                        GROUP_NO_MAIT=('Node', )),
                        MODELE=model)

reslin = MECA_STATIQUE(CHAM_MATER=fieldmat,
                       EXCIT=(_F(CHARGE=Load),
                              _F(CHARGE=g),
                              _F(CHARGE=Symmetry),
                              _F(CHARGE=Remote)),
                       MODELE=model)

reslin = CALC_CHAMP(reuse=reslin,
                    CONTRAINTE=('SIGM_NOEU', 'SIGM_ELNO'),
                    CRITERES=('SIEQ_NOEU', 'SIEQ_ELNO'),
                    FORCE=('REAC_NODA', ),
                    RESULTAT=reslin)

IMPR_RESU(FORMAT='MED',
          RESU=_F(INFO_MAILLAGE='OUI',
                  RESULTAT=reslin),
          UNITE=80)

FIN()