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#1 2019-06-21 15:25:26

Forestsun
Member
Registered: 2019-04-02
Posts: 10

Transient mechanical analysis under an evolutionary temperature field

Hello,
Currently I have a very specific problem when using Code aster. I followed some thermomechanical analysis example and found that there exist no examples about this kind of coupled problems in a transient way to solve mechanical model under a calculated evolutionary temperature field. I have already using command to assign the evol_therm on my mechanical model:

MECATH=AFFE_MATERIAU(MAILLAGE=MAIL,
                       MODELE=MODMECA,
                       AFFE=_F(TOUT='OUI',
                               MATER=MATER,),
                       AFFE_VARC=_F(TOUT='OUI',
                                    NOM_VARC='TEMP',
                                    EVOL=TEMPE,
                                    VALE_REF=0.0,),)

So what else should I do to execute the dynamic analysis on the mechanical model, if we assume that there is no external loads on this model?
(When using DYNA_VIBRA command somehow I have to define a harmonic exitation which is not necessary in this case. Are there any other possibilities? )

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#2 2019-06-22 12:32:46

Anirudh
Member
Registered: 2017-09-11
Posts: 252

Re: Transient mechanical analysis under an evolutionary temperature field

Hi,
maybe you can find some answers here https hmm /youtu.be/1ZNsgykHnGE
1- Did you do transient thermal correctly?
2- Did you use PROJ_CHAMP to project thermal model on mechanical? Make sure to check the box PROJECTION =YES. Also try using DYNA_NON_LINE and play around a bit with its initial conditions to see if you can include thermal effects. The challenge would be to apply evolving temperature field on the deforming mesh nodes under dynamic loading.

Anirudh

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#3 2019-06-26 14:31:24

Forestsun
Member
Registered: 2019-04-02
Posts: 10

Re: Transient mechanical analysis under an evolutionary temperature field

Anirudh wrote:

Hi,
maybe you can find some answers here https hmm /youtu.be/1ZNsgykHnGE
1- Did you do transient thermal correctly?
2- Did you use PROJ_CHAMP to project thermal model on mechanical? Make sure to check the box PROJECTION =YES. Also try using DYNA_NON_LINE and play around a bit with its initial conditions to see if you can include thermal effects. The challenge would be to apply evolving temperature field on the deforming mesh nodes under dynamic loading.

Anirudh


Hi thanks a lot for your reply. I think that the2 points you mentioned have already been done. But the main problem is that when the code aster tring to do the coupling, it has to first calculate and apply the internal load imposed by temerature field on the mechanical model. But in the dynamic mechanical analysis this load can not be easily decomposed cleanly into spatial dependent and time dependent... I also tried with DEFI_FONCTION with first storing the history of the these thermal internal loads but it does not work... Then I have to do this in a self implemented loop but is it a multistage static problem or a real dynamic case?

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#4 2019-07-01 05:18:05

Anirudh
Member
Registered: 2017-09-11
Posts: 252

Re: Transient mechanical analysis under an evolutionary temperature field

Hi,
try having a look at FORMA30 testcase.  It does have a part dealing with STAT_NON_LINE coupled with thermal loading. I have not tried it but it should work similarly for DYNA_NON_LINE.

Regards
Anirudh

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