【讨论】How to understand the code of DDSDDE?

lfzhu

C
C       JACOBIAN
C
          EFFG=EG*SYIELD/SMISES
          EFFG2=TWO*EFFG
          EFFG3=THREE*EFFG2/TWO
          EFFLAM=(EBULK3-EFFG2)/THREE
          DO 220 K1=1,NDI
             DO 210 K2=1,NDI
                DDSDDE(K2,K1)=EFFLAM
  210         CONTINUE
             DDSDDE(K1,K1)=EFFG2+EFFLAM
  220      CONTINUE
          DO 230 K1=NDI+1,NTENS
             DDSDDE(K1,K1)=EFFG
  230      CONTINUE
          DO 250 K1=1,NTENS
             DO 240 K2=1,NTENS
                DDSDDE(K2,K1)=DDSDDE(K2,K1)+FLOW(K2)*FLOW(K1)
     1                                       *(EFFHRD-EFFG3)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
help me!!!!!
  
  240         CONTINUE
  250      CONTINUE
        ENDIF
      ENDIF

galever

what do you mean? DDSDDE is just a 2 dimensional array.

lfzhu

This is a subroutine from
ABAQUS Verification Manual, 4.1.17 UMAT and UHYPER
I want the derivation of the expression  FLOW(K2)*FLOW(K1)*(EFFHRD-EFFG3)  
  
Thanks

ghostfp

there are many examples and discussion about UMAT ahead.
you'd better search and look through.