Hi, I'm trying to use the UMAT subroutine for time-dependent elastic modulus analysis. Some of you might recommend that I use the field method. Actually, I already did it, but I face a new problem if the time increment is large. It is hard to use the field method since I have defined each time-increment magnitude according to the field that I define. So, in this case, I think the UMAT subroutine is a good idea. I'm trying to make the UMAT subroutine code with the scenario that I want to update the elastic modulus (E) in some time cases (28 (T1), 50 (T2), 100 (T3), 150 (T4), 200 (T5), 250 (T6), 300 (T7), 350 (T8), and 365 (T9) days). Then, I make a step with time period 365 and increment 1. And then I defined the updated elastic modulus as STATEV. I defined 9 STATEV for each time case. When I submitted the job, the job was complete using the below codes, and when I checked the STATEV results, they also corroborated well with my hand calculation results. The problem is that I want to extract the data for stress, displacement, and others for each time case. When I tried to extract the results using the below codes, I found that the results just refer to the least time case (28 days) for each time. Can someone help me? My model is a 2D plane stress model.

Abaqus ​​​​​​​

SUBROUTINE UMAT(STRESS,STATEV,DDSDDE,SSE,SPD,SCD,
1 RPL,DDSDDT,DRPLDE,DRPLDT,
2 STRAN,DSTRAN,TIME,DTIME,TEMP,DTEMP,PREDEF,DPRED,CMNAME,
3 NDI,NSHR,NTENS,NSTATV,PROPS,NPROPS,COORDS,DROT,PNEWDT,
4 CELENT,DFGRD0,DFGRD1,NOEL,NPT,LAYER,KSPT,JSTEP,KINC)
C
INCLUDE 'ABA_PARAM.INC'
C
CHARACTER*80 CMNAME
DIMENSION STRESS(NTENS),STATEV(NSTATV),
1 DDSDDE(NTENS,NTENS),DDSDDT(NTENS),DRPLDE(NTENS),
2 STRAN(NTENS),DSTRAN(NTENS),TIME(2),PREDEF(1),DPRED(1),
3 PROPS(NPROPS),COORDS(3),DROT(3,3),DFGRD0(3,3),DFGRD1(3,3),
4 JSTEP(4)
C  
PARAMETER (ZERO=0.0D0, ONE=1.0D0, TWO=2.0D0, S=0.38D0, T0=28D0)
C  
E=PROPS(1)
v=PROPS(2)
T1=PROPS(3)
T2=PROPS(4)
T3=PROPS(5)
T4=PROPS(6)
T5=PROPS(7)
T6=PROPS(8)
T7=PROPS(9)
T8=PROPS(10)
T9=PROPS(11)
C  
IF (TIME(2).LE.T1) THEN
DO i=1, NTENS
DO j=1, NTENS
DDSDDE(i,j)=ZERO
END DO
END DO
ET1=E*(EXP(S*(1-(T0/T1)**(0.5))))**(0.5)
DDSDDE(1,1)=ET1/(ONE-v*v)
DDSDDE(2,2)=ET1/(ONE-v*v)
DDSDDE(3,3)=ET1*(ONE-v)/(TWO*(ONE-v*v))
DDSDDE(1,2)=ET1*v/(ONE-v*v)
DDSDDE(2,1)=ET1*v/(ONE-v*v)
DO i=1, NTENS
DO j=1, NTENS
STRESS(i)=STRESS(i)+DDSDDE(i,j)*DSTRAN(j)
END DO
END DO
ELSEIF (TIME(2).LE.T2) THEN
DO i=1, NTENS
DO j=1, NTENS
DDSDDE(i,j)=ZERO
END DO
END DO
ET2=E*(EXP(S*(1-(T0/T2)**(0.5))))**(0.5)
DDSDDE(1,1)=ET2/(ONE-v*v)
DDSDDE(2,2)=ET2/(ONE-v*v)
DDSDDE(3,3)=ET2*(ONE-v)/(TWO*(ONE-v*v))
DDSDDE(1,2)=ET2*v/(ONE-v*v)
DDSDDE(2,1)=ET2*v/(ONE-v*v)
DO i=1, NTENS
DO j=1, NTENS
STRESS(i)=STRESS(i)+DDSDDE(i,j)*DSTRAN(j)
END DO
END DO
ELSEIF (TIME(2).LE.T3) THEN
DO i=1, NTENS
DO j=1, NTENS
DDSDDE(i,j)=ZERO
END DO
END DO
ET3=E*(EXP(S*(1-(T0/T3)**(0.5))))**(0.5)
DDSDDE(1,1)=ET3/(ONE-v*v)
DDSDDE(2,2)=ET3/(ONE-v*v)
DDSDDE(3,3)=ET3*(ONE-v)/(TWO*(ONE-v*v))
DDSDDE(1,2)=ET3*v/(ONE-v*v)
DDSDDE(2,1)=ET3*v/(ONE-v*v)
DO i=1, NTENS
DO j=1, NTENS
STRESS(i)=STRESS(i)+DDSDDE(i,j)*DSTRAN(j)
END DO
END DO
ELSEIF (TIME(2).LE.T4) THEN
DO i=1, NTENS
DO j=1, NTENS
DDSDDE(i,j)=ZERO
END DO
END DO
ET4=E*(EXP(S*(1-(T0/T4)**(0.5))))**(0.5)
DDSDDE(1,1)=ET4/(ONE-v*v)
DDSDDE(2,2)=ET4/(ONE-v*v)
DDSDDE(3,3)=ET4*(ONE-v)/(TWO*(ONE-v*v))
DDSDDE(1,2)=ET4*v/(ONE-v*v)
DDSDDE(2,1)=ET4*v/(ONE-v*v)
DO i=1, NTENS
DO j=1, NTENS
STRESS(i)=STRESS(i)+DDSDDE(i,j)*DSTRAN(j)
END DO
END DO
ELSEIF (TIME(2).LE.T5) THEN
DO i=1, NTENS
DO j=1, NTENS
DDSDDE(i,j)=ZERO
END DO
END DO
ET5=E*(EXP(S*(1-(T0/T5)**(0.5))))**(0.5)
DDSDDE(1,1)=ET5/(ONE-v*v)
DDSDDE(2,2)=ET5/(ONE-v*v)
DDSDDE(3,3)=ET5*(ONE-v)/(TWO*(ONE-v*v))
DDSDDE(1,2)=ET5*v/(ONE-v*v)
DDSDDE(2,1)=ET5*v/(ONE-v*v)
DO i=1, NTENS
DO j=1, NTENS
STRESS(i)=STRESS(i)+DDSDDE(i,j)*DSTRAN(j)
END DO
END DO
ELSEIF (TIME(2).LE.T6) THEN
DO i=1, NTENS
DO j=1, NTENS
DDSDDE(i,j)=ZERO
END DO
END DO
ET6=E*(EXP(S*(1-(T0/T6)**(0.5))))**(0.5)
DDSDDE(1,1)=ET6/(ONE-v*v)
DDSDDE(2,2)=ET6/(ONE-v*v)
DDSDDE(3,3)=ET6*(ONE-v)/(TWO*(ONE-v*v))
DDSDDE(1,2)=ET6*v/(ONE-v*v)
DDSDDE(2,1)=ET6*v/(ONE-v*v)
DO i=1, NTENS
DO j=1, NTENS
STRESS(i)=STRESS(i)+DDSDDE(i,j)*DSTRAN(j)
END DO
END DO
ELSEIF (TIME(2).LE.T7) THEN
DO i=1, NTENS
DO j=1, NTENS
DDSDDE(i,j)=ZERO
END DO
END DO
ET7=E*(EXP(S*(1-(T0/T7)**(0.5))))**(0.5)
DDSDDE(1,1)=ET7/(ONE-v*v)
DDSDDE(2,2)=ET7/(ONE-v*v)
DDSDDE(3,3)=ET7*(ONE-v)/(TWO*(ONE-v*v))
DDSDDE(1,2)=ET7*v/(ONE-v*v)
DDSDDE(2,1)=ET7*v/(ONE-v*v)
DO i=1, NTENS
DO j=1, NTENS
STRESS(i)=STRESS(i)+DDSDDE(i,j)*DSTRAN(j)
END DO
END DO
ELSEIF (TIME(2).LE.T8) THEN
DO i=1, NTENS
DO j=1, NTENS
DDSDDE(i,j)=ZERO
END DO
END DO
ET8=E*(EXP(S*(1-(T0/T8)**(0.5))))**(0.5)
DDSDDE(1,1)=ET8/(ONE-v*v)
DDSDDE(2,2)=ET8/(ONE-v*v)
DDSDDE(3,3)=ET8*(ONE-v)/(TWO*(ONE-v*v))
DDSDDE(1,2)=ET8*v/(ONE-v*v)
DDSDDE(2,1)=ET8*v/(ONE-v*v)
DO i=1, NTENS
DO j=1, NTENS
STRESS(i)=STRESS(i)+DDSDDE(i,j)*DSTRAN(j)
END DO
END DO
ELSEIF (TIME(2).LE.T9) THEN
DO i=1, NTENS
DO j=1, NTENS
DDSDDE(i,j)=ZERO
END DO
END DO
ET9=E*(EXP(S*(1-(T0/T9)**(0.5))))**(0.5)
DDSDDE(1,1)=ET9/(ONE-v*v)
DDSDDE(2,2)=ET9/(ONE-v*v)
DDSDDE(3,3)=ET9*(ONE-v)/(TWO*(ONE-v*v))
DDSDDE(1,2)=ET9*v/(ONE-v*v)
DDSDDE(2,1)=ET9*v/(ONE-v*v)
DO i=1, NTENS
DO j=1, NTENS
STRESS(i)=STRESS(i)+DDSDDE(i,j)*DSTRAN(j)
END DO
END DO
ENDIF
C  
STATEV(1)=ET1
STATEV(2)=ET2
STATEV(3)=ET3
STATEV(4)=ET4
STATEV(5)=ET5
STATEV(6)=ET6
STATEV(7)=ET7
STATEV(8)=ET8
STATEV(9)=ET9
C  
RETURN
END