Hi Everyone,

I am running a thermal mechanical simulation using ABAQUS subroutine GAPCON to simulate the heat transfer behaviour at the interface in a die and a casting.

So In a 2D and a 3D model the model is failing at the corner most node of the die and casting could not understand why.

This is the sample 3D model 

      subroutine gapcon(ak,d,flowm,temp,predef,time,ciname,
    1  slname,msname,coords,noel,node,npred,kstep,kinc)
c
     include 'aba_param.inc'
c
     character*80 ciname,slname,msname
     dimension flowm(2),temp(2),predef(2,*),
    1          ak(5),d(2),coords(3),time(2)
c
c       define gap conductivity dependent on temperature.
    
     
     
     real*8 :: GC_slope, GC_intercept, GAP_slope, GAP_intercept
   
    if(ADJUSTL(TRIM(ciname)) == 'Casting Side die int') then
        
        ak(1) = 1500.00
       return
        
    end if
    
    
     
     if(temp(1) > 610.00 .and. temp(1) <= 720.00) then
      
         ak(1) = 2000.00
    
     elseif (temp(1) > 555.00 .and. temp(1) <= 610.00) then
     
          ak(1) = (7.277 * temp(1)) - 2436.34
    
     else if (temp(1)<= 555) then
    
        if (d(1) > 0.0 .and. d(2)==0) then
           
            ak(1) = 52 / (0.052 + (1000* d(1)))
            ak(2) = -52000 / ((0.052 + (d(1)*1000))**2)
            
        end if

        
      end if
     
     return
     end

This is my GAPCON subroutine so just as the temperature goes below 555 as it comes to 554 the model fails and the message file shows that the "Heat Flux equilibrium not achieved "

Could anyone tell me what should I do in such a situation ?

It is a little urgent please can anyone help who has developed GAPCON earlier ?

Thanks and Regards 

Manik Gupta