SUBROUTINE UHARD(SYIELD,HARD,EQPLAS,EQPLASRT,TIME,DTIME,TEMP,
     1     DTEMP,NOEL,NPT,LAYER,KSPT,KSTEP,KINC,CMNAME,NSTATV,
     2     STATEV,NUMFIELDV,PREDEF,DPRED,NUMPROPS,PROPS)
C
      INCLUDE 'ABA_PARAM.INC'
C
      INTEGER i
      CHARACTER*80 CMNAME
      DOUBLE PRECISION rinf,pm,sy,em,ey_0,strain,strain_0,SYIELD_0
      DIMENSION HARD(5),STATEV(NSTATV),TIME(*),
     $          PREDEF(NUMFIELDV),DPRED(*),PROPS(*)
      PARAMETER (one=1.d0)

C      user coding to define SYIELD,HARD(1),HARD(2),HARD(3)
C
C
C
C     Yield Stress calculated from Exponential Law
      xk = PROPS(1)
      pn = PROPS(2)
      sy = PROPS(3)
      xkpa = PROPS(4)
      xm = PROPS(5)
C
C
      SYIELD0 = sy + xk*EQPLAS**pn
      SYIELD = ((EQPLASRT/xkpa)**(one/xm)+one)*SYIELD0
      HARD(1) = xk*EQPLAS**(pn-one)
      HARD(2)=0.0
      if(EQPLASRT.ne.zero)then
         HARD(2) = SYIELD0/xkpa*(EQPLASRT/xkpa)**(one/xm-one)
      end if
      HARD(3) = 0.0
C
      RETURN
      END