This example demonstrates the implementation of (HENSEL - SPITTEL ) model for the AZ31 material through flowstress user routine.

Flow stress HENSEL - SPITTEL model:

Flow stress (YS) = A*(exp(M1*T))*(Strain**M2)*(Strain rate**M3)*(exp(M4/Strain)))


Where,

T - Temerature, C
A, M1, M2, M3 and M4 are material constants.
Values of A, M1, M2, M3 and M4 will be read from GUI into routine using the Code:

CHARACTER*80 IUSRVL
COMMON /IUSR/ IUSRVL(10)

READ(IUSRVL(1),*) A, M1, M2, M3 and M4


The usr_mtr.f file contains user routine implemented in 


C********************************************************************

      SSUBROUTINE UFLOW2(YS,YPS,FIP,TEPS,EFEPS,TEMP)

C********************************************************************
C
C
C
C********************************************************************

      IMPLICIT REAL*8 (A-H,O-Z), DOUBLEPRECISION (I-N)
C
C ****    USER DEFINED VARIABLES ****
C
      CHARACTER*80 IUSRVL
      COMMON /IUSR/ IUSRVL(10)
C     
C     TO READ DATA (10 RESERVED LINES)
C        READ(IUSRVL(LINE NUMBER),*) DATA1,DATA2,DATA3...
C
C     TO WRITE DATA (10 RESERVED LINES)
C        WRITE(IUSRVL(LINE NUMBER),*) NEWDATA1, NEWDATA2, NEWDATA3 ...
C
C ****     END    ****
C
C     SEE UFLOW1 FOR DETAILED DESCRIPTION
C
C   HENSEL - SPITTEL EQUATION
C  YS = A*(EXP(M1*TEMP))*(TEPS**M2)*(EFEPS**M3)*(EXP(M4/TEPS))
              READ(IUSRVL(1),*) A, M1, M2, M3, M4
             IF (TEPS.LE.2.E-3) TEPS=2.E-3
             IF (EFEPS.LE.2.E-3) EFEPS=2.E-3
             YS = A*(EXP(M1*TEMP))*(TEPS**M2)*(EFEPS**M3)*(EXP(M4/TEPS))
             YPS= A*(EXP(M1*TEMP))*(EFEPS**M3) 
     &     *(((-M4*TEPS**(M2-2))* (EXP(M4/TEPS)))+ 
     &      ((M2*(EXP(M4/TEPS))*TEPS**(M2-1))))
             FIP = A*EXP(M1*TEMP)*(TEPS**M2)*EXP(M4/TEPS)*M3
     &     * (EFEPS**(M3-1))    
             RETURN
             END
C********************************************************************


Executing the User routine:

Open the pre-processor and import 2D_EXTRUSION.KEY file from 2D_Examples folder.

Go to Material page and select AZ31 material. For Flowsress model select user routine number as 2. 

Go to Simulation controls and select Advanced User defined tab. In first row enter A, M1, M2, M3 and M4 as 709.4, -0.0065, -0.1538, 0.1202, -0.0261,

Save the Key file and Generate DB. 

Make a copy of the release folder …\2D\UserRoutine\DEF_SIM (and usr_mtr.f modified as indicated above)

Open the FORTRAN Absoft 11 and open the DEFORM 2d user routine DEF_SIM_USR_Absoftv110.atools file from this copied location, 
and build local FEM engine DEF_SIM.EXE

Two ways to run this model using the user defined material model 
1. 
Build the executing files and paste the generated DEF_SIM.EXE in "..\2D\" folder. (first backup release version of DEF_SIM.EXE)
Run the simulation and observe material behavior in post processor after the completion of simulation.
2. 
create a file DEF_SIM_DIR.DAT with first line indicating the path to the folder holding this newly build DEF_SIM.EXE
Run the simulation and observe material behavior in post processor after the completion of simulation.

(point tracking at few locations and plot stress vs strain response can confirm the material model implemented)
