Combined raditaion and convective heat transfer analysis in Abaqus

[anoop_1989]

Dear all
I would like to give combined radiation and convective heat transfer coefficient for the thermal analysis of the welding process in Abaqus. How can I give the same?

The equation to be used for predicting the same is

h=0.00668T when T<<500oC
0.231T-82.1 when t>>500oC

Paper ref:3D finite element simulation of temperature distribution, residual stress and
distortion on 304 stainless steel plates using GTA welding,D. Venkatkumar* and D. Ravindran

 

[FEA way]

To define temperature-dependent convection you have to first use Create Interaction Property —> Film condition. Check the box „Use temperature-dependent data” and specify the values. Then use Create Interaction —> Surface film condition. Select surfaces and in the Edit Interaction window change the Definition from Embedded Coefficient to Property Reference. Select previosuly created interaction property (if it’s not added automatically).

Radiation is normally defined in Abaqus by providing the value of emissivity (no option for temperature dependence unless you use cavity radiation). But if you want to account for it indirectly, by adding its contribution to heat transfer coefficient then you have to follow the procedure described in the first paragraph.

Another option would be to write user subroutine but this won’t be so easy.

 

[anoop_1989]

Thank you

I am attaching the heat flux calculation I have done to give as DFLUX input in Abaqus subroutine.But the temperature is found to be high after giving this heat flux values in the subroutine. As per the article maximum temperature was found to be 1600 degree Celcius. Can anyone please correct me if there is any mistake?

SUBROUTINE DFLUX(FLUX,SOL,KSTEP,KINC,TIME,NOEL,NPT,COORDS,
1 JLTYP,TEMP,PRESS,SNAME)
INCLUDE 'ABA_PARAM.INC'
DIMENSION FLUX(2),TIME(2),COORDS(3)
CHARACTER*80 SNAME
REAL t,x,y,z,Q,cf,cr,b,a,Amp,volt,n
REAL z1,x2,y2,z2,v,ff,fr,d1,d2,l
REAL FLUX1

t = time(2)

c welding arc
cf =.003
cr =.006
b = .001
a = .00305


c speed of welding in the Z direction
v=.0024
z1 = v*t
c coordinate
x = COORDS(1)
y = COORDS(2)
z = COORDS(3)

c
x2=x
y2=y
z2=z-z1
c
Qf=1763600000000
Qr=146900000000
if(JLTYP.EQ.1) then
if(KSTEP.EQ.1) then
c Goldak's volumetric heat source model
if(z2<=0) then
FLUX(1)=Qr*exp(-((x2)**2/a**2+(y2)**2/b**2+(z2)**2/cr**2))


else if (z2>0) then
FLUX(1)=Qf*exp(-((x2)**2/a**2+(y2)**2/b**2+(z2)**2/cf**2))


end if
end if
end if

return
end

 

[anoop_1989]

Attaching the inp file for the model