根据文献,编写基于 YLD2000 - 2D 屈服准则及变弹性模量的 umat 子程序的 Fortran 详细代码示例
时间: 2024-09-24 20:30:27 浏览: 34
基于YLD2000-2D屈服准则及变弹性模量的UMAT子程序的Fortran代码并未直接提供在文献中。不过,根据提供的文献内容,我们可以概述如何编写这样的子程序。下面提供的是一个概念性的框架,具体细节需要根据实际的材料参数和模型调整:
```fortran
SUBROUTINE UMAT(STRESS,STATEV,STRAN,DSTRAN,SROD,RDOT,
* ELDO,FORD,DPORD,DMINIT,CONST,DCONST,
* TIME,DTIME,TEMP,DTEMP,PNEWDT,CMNAME,
* NSTR,NSTV,NTENS,NSTATV,KSTEP,KINC,
* JACOB,DMATRIX)
IMPLICIT NONE
! Declare variables and arrays
INTEGER*4 KINC, KSTEP, NSTV, NTENS, NSTATV, NSTR
REAL*8 STRESS(NTENS), STRAN(NSTR), DSTRAN(NSTR), STATEV(NSTATV)
REAL*8 CONST(55), DPORD(NTENS,NSTATV), DMINIT(NSTATV)
REAL*8 RDOT(NTENS), SROD(NTENS), ELDO(NTENS), FORD
REAL*8 TIME(3), DTIME(3), TEMP, DTEMP, PNEWDT
CHARACTER*(*) CMNAME
REAL*8 JACOB(9,NTENS,NTENS), DMATRIX(9,NTENS,NTENS)
! Initialize the stress tensor and material properties
DO I = 1, NTENS
STRESS(I) = 0.D0
END DO
! Define initial elastic modulus (E0) and other parameters
REAL*8 E0, Ea, xi, alpha1, alpha2, alpha3, alpha4, alpha5, alpha6, alpha7, alpha8
E0 = CONST(1) ! Initial elastic modulus for RD direction
Ea = CONST(2) ! Material parameter related to final elastic modulus
xi = CONST(3) ! Parameter controlling the rate of change in modulus
alpha1 = CONST(4) ! Anisotropy parameter 1
alpha2 = CONST(5) ! Anisotropy parameter 2
alpha3 = CONST(6) ! Anisotropy parameter 3
alpha4 = CONST(7) ! Anisotropy parameter 4
alpha5 = CONST(8) ! Anisotropy parameter 5
alpha6 = CONST(9) ! Anisotropy parameter 6
alpha7 = CONST(10) ! Anisotropy parameter 7
alpha8 = CONST(11) ! Anisotropy parameter 8
! Implement the YLD2000-2D yield criterion
CALL YIELD_CRITERION(STRESS, STRAN, DSTRAN, STATEV, E0, Ea, xi,
alpha1, alpha2, alpha3, alpha4, alpha5, alpha6, alpha7, alpha8)
! Update state variables and stresses based on plastic strain
CALL UPDATE_STATE_VARIABLES(STATEV, DSTRAN, STRESS, E0, Ea, xi)
! Return the updated values to ABAQUS
RETURN
CONTAINS
SUBROUTINE YIELD_CRITERION(STRESS, STRAN, DSTRAN, STATEV, E0, Ea, xi,
alpha1, alpha2, alpha3, alpha4, alpha5, alpha6, alpha7, alpha8)
! Implementation details for YLD2000-2D criteria
! ...
ENDSUBROUTINE YIELD_CRITERION
SUBROUTINE UPDATE_STATE_VARIABLES(STATEV, DSTRAN, STRESS, E0, Ea, xi)
! Update the state variables based on the new deformation
! Calculate the effective plastic strain and update the modulus accordingly
! ...
ENDSUBROUTINE UPDATE_STATE_VARIABLES
END SUBROUTINE UMAT
```
这个例子给出了UMAT的基本骨架,包括初始化、定义材料参数、执行YLD2000-2D屈服判据,更新状态变量等内容。具体的实现细节如屈服准则的计算和状态变量的更新需要根据文献中提到的方法来填充。