**** *****************************************************************************
**UMAT子程序接口,接口中的全局变量可以参考Abaqus User Subroutines Reference Manual
**中,关于UMAT的介绍,对所有全局变量参数给出详细的介绍
*********************************************************************************
aC 4X4 JACOBIAN THEN CONDENSATION WITH REGULARIZATION
c (energy due to viscous regularization is calculated)
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,KSTEP,KINC)
C
INCLUDE 'ABA_PARAM.INC'
C
CHARACTER*80 CMNAME
DIMENSION STRESS(NTENS),STATEV(NSTATV),
1 DDSDDE(NTENS,NTENS),
2 DDSDDT(NTENS),DRPLDE(NTENS),
3 STRAN(NTENS),DSTRAN(NTENS),TIME(2),PREDEF(1),DPRED(1),
4 PROPS(NPROPS),COORDS(3),DROT(3,3),DFGRD0(3,3),DFGRD1(3,3)
**********************************************************************************
**********************************************************************************
**定义子程序局部变量,用于子程序内部计算使用。
**下面对各个局部变量给出英文解释
**********************************************************************************
DIMENSION STRANT(6),TSTRANT(4)
DIMENSION CFULL(6,6),CDFULL(6,6)
DIMENSION DDFDE(6), DDMDE(6), DCDDF(6,6), DCDDM(6,6)
DIMENSION ATEMP1(6), ATEMP2(6), TDDSDDE(6,6)
DIMENSION OLD_STRESS(6)
DIMENSION DOLD_STRESS(6),D_STRESS(6)
PARAMETER (ZERO = 0.D0,ONE = 1.D0,TWO = 2.D0, HALF = 0.5D0)
C****************************
C STRANT..... STRAIN AT THE END OF THE INCREMENT
C TSTRANT.....TEMPORARY ARRAY TO HOLD THE STRAIN FOR PLANE STRESS PROBLEM
C CFULL.......FULL 6X6 ELASTICITY MATRIX
C CDFULL......FULL 6X6 DAMAGED ELASTICITY MATRIX
C DDFDE....... D DF/D E
C DDMDE....... D DM/D E
C DCDDF....... D C/ D DF THE DERIVATIVE OF THE FULL MATRIX OVER DF
C DCDDM........D C/ D DM THE DERIVATIVE OF THE FULL MATRIX OVER DM
C ATEMP1,ATEMP2...TEMPORARY ARRAY USED IN JACOBIAN CALCULATION
C TDDSDDE.....UNCONDENSED JACOBIAN MATRIX FOR PLANE STRESS PROBLEM
C OLD_STRESS...STRESS AT THE BEGINNING OF THE INCREMENT, SAVED FOR THE ENERGY
C COMPUTATION
C DOLD_STRESS...STRESS AT THE BEGINNING OF THE INCREMENT,
C IF THERE'S NO VISCOUS REGULARIZATION
C D_STRESS...STRESS IF THERE'S NO VISCOUS REGULARIZATION, THE ABOVE IS CALCULATED