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Code_Aster contact analysis - train rail

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11 years 8 months ago #7067 by Kev
Code_Aster contact analysis - train rail was created by Kev
Hi All,

New to CAE Linux and code_aster in general. I am trying to carry out an analysis of the stresses within rail track under the load exhibited by the train wheel.

I have modelled a section of track and a wheel (attached). I was intending to use the linear elastic wizard present in Salome_Meca to do a simple analysis of the problem. Setting degrees of freedom 0, 0, 0 on the base face of the sleepers and applying pressure either in the lower half of the axle hole in the wheel, or adding an axle with some loading faces to apply the loading purely vertically. However, have come to realisation that the wizard will not model the contact between the wheel and rail.

I would like some guidance on how to achieve the analysis.

I originally posted in the Salome Platform forum for some advice, but was referred to the code_aster forum, I am currently awaiting an account to post there, but then decided to try here.

The guidance from the Salome forum was
"What I would do:
mesh rail track and wheel as two separate bodies (that may and maybe should just make contact to each other).
Then in Code-Aster define a contact algorithm for this interface. Although this might be quite tricky since the interface is a point because of the two areas with double radii, it can be done. But switch to Code-Aster forum for this specific problem."

Is there anybody who could help here?

Many Thanks,

Kev
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11 years 8 months ago #7068 by Kev
Replied by Kev on topic Re: Code_Aster contact analysis - train rail
Sorry, for the miss posting, could this please be moved to the code_aster forum...

Many Thanks
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11 years 8 months ago - 11 years 8 months ago #7069 by kwou
Replied by kwou on topic Re: Code_Aster contact analysis - train rail
Hoi Kevin

This forum is allright, no need to change to Code-Aster (but you may of course change to that).
Can you post the command file from the Salome-Meca session? It is easier for a start.
Interest: structural mechanics, solar energy (picture at 'my location' shows too little pv panels)

--
kind regards - kees
Last edit: 11 years 8 months ago by kwou.
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11 years 8 months ago #7071 by Kev
Replied by Kev on topic Re: Code_Aster contact analysis - train rail
Hi,

Thanks for the reply, I post the command file I have been working, I have attempted to load 2 individual mesh files and assemble into a single mesh in the command file. I am a little stuck after here on what to do next?

I will have a little more time tomorrow and will make further attempts and post a better set of files...

Many Thanks,

Kev

comm

DEBUT();

MA=DEFI_MATERIAU(ELAS=_F(E=210000000000.0,
NU=0.3,),);

wheel=LIRE_MAILLAGE(UNITE=20,
FORMAT='MED',);

rail=LIRE_MAILLAGE(UNITE=21,
FORMAT='MED',);

mesh=ASSW_MAILLAGE(MAILLAGE_1=wheel,
MAILLAGE_2=rail,
OPERATION='SUPERPOSE',);

mesh=MODI_MAILLAGE(reuse=mesh,
MAILLAGE=mesh,
ORIE_PEAU_3D=_F(GROUP_MA=('vert_load','sleepers',),),);

MODE=AFFE_MODELE(MAILLAGE=mesh,
AFFE=_F(TOUT='OUI',
PHENOMENE='MECANIQUE',
MODELISATION='3D',),);

MATE=AFFE_MATERIAU(MAILLAGE=mesh,
AFFE=_F(TOUT='OUI',
MATER=MA,),);

CHAR=AFFE_CHAR_MECA(MODELE=MODE,
DDL_IMPO=(
_F(GROUP_MA='sleepers',
DX=0.0,
DY=0.0,
DZ=0.0,),
),
PRES_REP=(
_F(GROUP_MA='vert_load',
PRES=300000.0,),
),
);

RESU=MECA_STATIQUE(MODELE=MODE,
CHAM_MATER=MATE,
EXCIT=_F(CHARGE=CHAR,),);

RESU=CALC_ELEM(reuse=RESU,
MODELE=MODE,
CHAM_MATER=MATE,
RESULTAT=RESU,
OPTION=('SIGM_ELNO','SIEQ_ELNO',),
EXCIT=_F(
CHARGE=CHAR,),);

RESU=CALC_NO(reuse=RESU,
RESULTAT=RESU,
OPTION=('SIGM_NOEU', 'SIEQ_NOEU', ),);

IMPR_RESU(FORMAT='MED',
UNITE=80,
RESU=_F(MAILLAGE=mesh,
RESULTAT=RESU,
NOM_CHAM=('SIGM_NOEU','SIEQ_NOEU','DEPL',),),);

FIN();
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11 years 8 months ago #7077 by Kev
Replied by Kev on topic Re: Code_Aster contact analysis - train rail
I have done more on this problem and having more than a little trouble with the french error msgs being thrown at me...!

I have been basing command file on this www.caelinux.org/wiki/images/a/a2/Contact.tar.gz

I have attached the command file and other project files I have been working on, I think maybe I have a problem of two versions of syntax as, there were many many errors when I tried to run the simulation. Also in the contact part, I have had to define two solid entities, which again I am not sure is right...?

Any help is greatly greatly received...!

Thanks,

Kev
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11 years 8 months ago - 11 years 8 months ago #7078 by kwou
Replied by kwou on topic Re: Code_Aster contact analysis - train rail
Hoi Kevin

French can be learned. Use Google translate (or whatever). Or asked a french speaking collegue. :laugh:
Which version of Code-Aster do you use (command syntax changed a lot lately)?


Alright: the error messages:

1)
Etape : MODI_MAILLAGE ligne : 33 fichier : 'fort.1'
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
! Mots cles inconnus :MODELE !
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

MeshQuad=MODI_MAILLAGE(reuse =MeshQuad,
MAILLAGE=MeshQuad,
ORIE_PEAU_2D=_F(GROUP_MA=('fix','vert',),),
MODELE=FEMQuad,);

I guess you have to remove MODELE=FEMQuad from the command (mesh (is Mailliage) is not a model).

2)
Etape : AFFE_CHAR_MECA ligne : 62 fichier : 'fort.1'
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
! Mots cles inconnus :TEMP_CALCULEE !
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

temp=AFFE_CHAR_MECA(MODELE=FEMQuad,
TEMP_CALCULEE=tempf,);

I am not sure why you need temperature. To start with, leave it out, contact is hard enough.

3)
Etape : AFFE_CHAR_MECA ligne : 75 fichier : 'fort.1'
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
! Mots cles inconnus :CONTACT !
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

#do not really understand this, rail and wheel and 3d groups defined in salome??
contact=AFFE_CHAR_MECA(MODELE=FEMQuad,
CONTACT=_F(APPARIEMENT='MAIT_ESCL',
RECHERCHE='NOEUD_BOUCLE',
METHODE='LAGRANGIEN',
PROJECTION='QUADRATIQUE',
GROUP_MA_MAIT='rail',
GROUP_MA_ESCL='wheel',
FROTTEMENT='COULOMB',
NB_REAC_MAXI=10,
COULOMB=.4,),);

related to 4) 5) and 6): ''wrong version of Code-Aster'' (changed syntax).


4)
Etape : STAT_NON_LINE ligne : 103 fichier : 'fort.1'
Mot cle Facteur :INCREMENT
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
! Mots cles inconnus :SUBD_PAS_MINI,SUBD_PAS !

Old version of stepping. Not valid in your version.

5)
Fin Mot cle Facteur :INCREMENT
Mot cle Facteur :COMP_ELAS
Mot-clé simple : DEFORMATION
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
! La valeur : 'GREEN' ne fait pas partie des choix possibles ('PETIT', !
! 'GROT_GDEP') !

Same here: old version of DEFORMATION, use 'PETIT' to start with (linear, small deformation).

6)
.... 'SIEF_ELNO_ELGA'
once again, old version. The upgrade of Code-Aster make a lot of tutorials obsolete cq using old syntax.

See next post for later version of contact definition (next page).
Interest: structural mechanics, solar energy (picture at 'my location' shows too little pv panels)

--
kind regards - kees
Last edit: 11 years 8 months ago by kwou.
Moderators: catux
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