Thermo-mechanical coupled Issue

[eleven]

Hi Everyone,
I am trying to use FEAP(version 85) to run a 2D-thermo-mechanical coupled problem with initial velocity defined. But the temperature field keeps zero all the time with the thermal expansion coefficient is 1. (I changed it to 1000, still got zeros for temperature.) I got the same results whatever values I used for the thermal expansion coefficient.
[PS: I ran the same problem with my own developed Matlab code. The results I got from FEAP match with the case that the thermal expansion coefficient is zero.]
Could you tell me how to develop a fully-coupled thermo-mechanial input file?
I attached my input file. Would you mind helping me to see if anything wrong with my input file?

Thank you so much!

[Prof. R.L. Taylor]

1. Check if you can you update to ver8.6.

2. The fully coupled thermo-mechanical is not documented and may still need revisions for things like plane stress.  To activate you need to add a record to the material sets

FOURier TEMP T_abs

Currently all the thermal energy is added, however, there is another parameter after T_abs to set the fraction, but it is not used by the elements.

Currently also  as the temperature changes it is not included with the T_abs.

[eleven]

Dear Prof. Taylor,

1) The equation I used is ρc∂T =−divq−Tref βTε ̇+Q, which is same in mannual86:section7.2.5. I add command "FOURier REFErence 1'' setting reference temperature to be 1. But the issue is still there. Does it work for version 8.5?
So far, I am not sure the problem is with my input or there is no suitable element I could use in FEAP8.5

2) Could FEAP 8.5 run a fully coupled thermo-mechanical 2D problem with governing equation:
ρc∂T =−divq−Tref βTε ̇+Q
ρa =div(sigma)+ρb

Best,
Eleven

[Prof. R.L. Taylor]

Yes, that appears to be what is solved - with deps/dt  where you have the epsilon.  But it is only coded in the standard displacement element not the mixed one.

Look in ./elements/solid2d/sld2d1.f for the coding -- using d(129) which is the absolute temperature.