Problems using subroutine UHARD

[tsiloufas]

Hello everyone.

I'm facing a problem with the subroutine UHARD. I want to create a simple power law equation for testing a bigger UMAT subroutine.

The equation I would like to implement is the Ludiwg equation: SIGMA_YIELD = SIGMA_0 + K*EQPLAS^N

Here is a copy of the full subroutine. It is very simple.

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
CHARACTER*80 CMNAME
DIMENSION HARD(3),STATEV(NSTATV),TIME(*),
$ PREDEF(NUMFIELDV),DPRED(*),PROPS(*)
C
C USES LUDWIG EQUATION: SIGMA_YIELD = SIGMA_0 + K*EQPLAS^N
C d(SIGMA)/d(EQPLAS) = K*N*EQPLAS^(N-1)
C USER INPUT:
C PROPS(1) = SIGMA_0
C PROPS(2) = K
C PROPS(3) = N
C
PARAMETER(ZERO=0.D0, ONE=1.D0)
C
C CALCULATE
C
SYIELD=PROPS(1) + PROPS(2)*EQPLAS**PROPS(3)
HARD(1)=PROPS(2)*PROPS(3)*EQPLAS**(PROPS(3)-ONE)
HARD(2)=ZERO
HARD(3)=ZERO

RETURN
END

------------------------------------------------------------

But the job exits with an error:

The executable C:\SIMULIA\Abaqus\6.10-1\exec\standard.exe aborted with system error code 144. Please check the .dat, .msg, and .sta files for error messages if the files exist.

But there is no clue in the .dat, .msg, .sta or .log. I think this is a problem with my coding, but I cannot fix it.

Thank you for your help and sorry for any mistakes. English is not my birth language.

Stergios Pericles Tsiloufas
Escola Politécnica
University of São Paulo
Brazil