#1 2017-03-08 11:33:34

mabr

Member

Registered: 2017-03-08

Posts: 3

[Solved] Thermal analysis with temperature dependent conduction

I was working on simple 2D example with material that has temperature dependent thermal conduction. The problem is that I don't know whether to use THER_LINE or THER_NON_LINE module, because THER_NON_LINE wants me to define  volumic specific heat (should i just assign it zero value?), which i don't need. My .comm file with THER_LINE looks like:

DEBUT(LANG='en',);

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

Lambda=DEFI_FONCTION(
                     NOM_PARA='TEMP',
                     VALE=(1.0 ,1.0 ,
                           5000.0 ,5000.0 ,),);

MATER=DEFI_MATERIAU(THER_FO=_F(LAMBDA=Lambda,),);

MODEL=AFFE_MODELE(MAILLAGE=MESH,
                  AFFE=_F(TOUT='OUI',
                          PHENOMENE='THERMIQUE',
                          MODELISATION='PLAN',),);

MATFIELD=AFFE_MATERIAU(MAILLAGE=MESH,
                       AFFE=_F(TOUT='OUI',
                               MATER=MATER,),);

LOADING=AFFE_CHAR_THER(MODELE=MODEL,
                       TEMP_IMPO=(_F(GROUP_MA='Edge_1',
                                     TEMP=100.0,),
                                  _F(GROUP_MA='Edge_2',
                                     TEMP=20.0,),),);

TEMP=THER_LINEAIRE(MODELE=MODEL,
                   CHAM_MATER=MATFIELD,
                   EXCIT=_F(CHARGE=LOADING,),);

IMPR_RESU(FORMAT='MED',
          RESU=_F(RESULTAT=TEMP,),);

FIN();

And the error I get is

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
   ! <S> Exception user raised but not interceptee.                          !
   ! The bases are fermees.                                                  !
   ! Type of the exception: error                                            !
   !                                                                         !
   !  Error during the interpolation of the function Lambda on the mesh M50, !
   !  it misses the parameter  TEMP                                          !
   !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Is there a problem with the mesh or am i missing something else?

Any response is appreciated.
Best regards,

Mat

Last edited by mabr (2017-03-15 14:47:09)

stephaneberger

Member

From: Strasbourg (France)

Registered: 2012-10-15

Posts: 70

Re: [Solved] Thermal analysis with temperature dependent conduction

HI,

You have to use THER_NON_LINE.
As soon as you have material properties which are not constant, you have to use a non linear solving method (mean THER_NON_LINE)

For the specific heat, you can make a test with 2 values. (Personnaly, I prefer entering a value with a good level of magnitude, for instance 500 J/kg.K for steel). In this way, if you want to run a transient calculation, the results will be correct.

stephane

mabr

Member

Registered: 2017-03-08

Posts: 3

Re: [Solved] Thermal analysis with temperature dependent conduction

Thank you for your answer.