ABAQUS umat

         SUBROUTINE UMAT(STRESS,STATEV,DDSDDE,SSE,SPD,SCD,RPL,DDSDDT,
    1 DRPLDE,DRPLDT,STRAN,DSTRAN,TIME,DTIME,TEMP,DTEMP,PREDEF,DPRED,
    2 CMNAME,NDI,NSHR,NTENS,NSTATV,PROPS,NPROPS,COORDS,DROT,
    3 PNEWDT,CELENT,DFGRDO,DFGRDl,NOEL,NPT,LAYER,KSPT,KSTEP,KINC)
      include 'aba_param.inc'
     CHARACTER*8 CMNAME
     DIMENSION STRESS(NTENS),STATEV(NSTATV),DDSDDE(NTENS,NTENS),
    1 DDSDDT(NTENS),DRPLDE(NTENS),STRAN(NTENS),DSTRAN(NTENS),
    2 TIME(2),PREDEF(1),DPRED(1),PROPS(NPROPS),COORDS(3),DROT(3,3),
    3 DFGRD0(3,3),DFGRDl(3,3)
C UMAT FOR ISOTROPIC ELASTICITY
C CANNOT BE USED FOR PLANE STRESS
C - ------ -
C PROPS(1) - E
C PROPS(2) - NU
CC
C      IF (NDI.NE.3) THEN
C             WRITE (6,*) 'THIS UMAT MAY ONLY BEUSED FOR ELEMENTS
C    1 WITH THREE DIRECT STRESS COMPONENTS'
C           CALL XIT
C      ENDIF
C
C ELASTIC PROPERTIES
       EMOD=PROPS(1)
       ENU=PROPS(2)
       EBULK3=EMOD/(1-2*ENU)
       EG2=EMOD/(1+ENU)
       EG=EG2/2
       EG3=3*EG
       ELAM=(EBULK3-EG2)/3
C
C ELASTIC STIFFNESS
C
       DO K1=1, NDI
          DO K2=1, NDI
            DDSDDE(K2, K1)=ELAM
          END DO
          DDSDDE(K1, K1)=EG2+ELAM
       END DO
       DO K1=NDI+1, NTENS
          DDSDDE(K1 ,K1)=EG
       END DO
C
C CALCULATE STRESS
C
       DO K1=1, NTENS
          DO K2=1, NTENS
              STRESS(K2)=STRESS(K2)+DDSDDE(K2,K1)*DSTRAN(K1)
          END DO
       END DO
C
         RETURN
       END