subroutine gapcon(ak,d,flowm,temp,predef,time,ciname,
     1  secname,mainname,coords,noel,node,npred,kstep,kinc)
c
      include 'aba_param.inc'
c
      character*80 ciname,secname,mainname
      dimension flowm(2),temp(2),predef(2,*),
     1          ak(5),d(2),coords(3),time(2)
c
c       define gap conductivity dependent on field variables.
        fvavg=0.5*(predef(1,1)+predef(2,1))
        if(fvavg.le.25.0)then
          ak(1)=15.0
        else if(fvavg.le.50.0)then
          ak(1)=15.0+5.4*(fvavg-25.0)
        else if(fvavg.le.75.0)then
          ak(1)=150.+6.0*(fvavg-50.0)
        else if(fvavg.le.100.0)then
          ak(1)=300.0+108.*(fvavg-75.0)
        else
          ak(1)=3000.
        end if
c     
      return
      end