C
CHARACTER*80 CMNAME,ORNAME CHARACTER*3 FLGRAY(15)
DIMENSION FIELD(NFIELD),STATEV(NSTATV),DIRECT(3,3), 1 T(3,3),TIME(2)
DIMENSION ARRAY(15),JARRAY(15),JMAC(*),JMATYP(*),COORD(*)
user coding to define FIELD and, if necessary, STATEV and PNEWDT
RETURN END
Variable to be defined（被定义的变量）
FIELD(NFIELD)
An array containing the field variables at the current material point. These are passed in with the values interpolated from the nodes at the end of the current increment, as specified with initial condition
definitions, predefined field variable definitions, or user subroutine UFIELD. The interpolation is performed using the same scheme used to interpolate temperatures: an average value is used for linear elements; an approximate linear variation is used for quadratic elements (also see “Solid (continuum) elements,” Section 27.1.1 of the Abaqus Analysis User's Manual). The updated values are used to calculate the values of material properties that are defined to depend on field variables and are passed into other user subroutines (CREEP, HETVAL, UEXPAN, UHARD, UHYPEL, UMAT, UMATHT, and UTRS) that are called at this material point. （一个数组包含着当前材料点上的场变量。在当前增量结束的节点通过内插法求得，作为指定的初始状态，预定义场变量或者只用子程序USDFLD。方法和温度的差值法相同：平均值用于线性单元；一个近似的线性变量被用于二次元素（可参考27.1.1）。这些更新的数据用来计算材料性能的数据，这些数值用场变量来定义，并且能够被子程序(CREEP, HETVAL, UEXPAN, UHARD, UHYPEL, UMAT, UMATHT, and UTRS)调用。）
Variables that can be updated（可以更新的变量）
STATEV(NSTATV)
An array containing the solution-dependent state variables. These are passed in as the values at the beginning of the increment. In all cases STATEV can be updated in this subroutine, and the updated values are passed into other user subroutines (CREEP, HETVAL, UEXPAN, UMAT, UMATHT, and UTRS) that are called at this material point. The number of state variables associated with this material point is defined as described in “Allocating space” in “User subroutines: overview,” Section 17.1.1 of the Abaqus Analysis User's Manual.
（一组数据用来保存解相关的变量。它们在增量开始时被接入。在所有的例子中，STATEV能够在子程序中被更新，并且被更新的数值能够在（CREEP, HETVAL, UEXPAN, UMAT, UMATHT, and UTRS）子程序中被调用。状态变量的数目与材料点的相关，在17.1.1中描述） PNEWDT
Ratio of suggested new time increment to the time increment being used (DTIME, see below). This variable allows you to provide input to the automatic time incrementation algorithms in Abaqus/Standard (if automatic time incrementation is chosen).
（推荐的新的时间增量和时间增量的比例。这个变量允许你提供输入到abaqus里面的自动时间增量的算法。）
PNEWDT is set to a large value before each call to USDFLD. （在USDFLD被调用之前，PNEWDT被设置成一个大的数值。）
If PNEWDT is redefined to be less than 1.0, Abaqus/Standard must abandon the time increment and attempt it again with a smaller time increment. The suggested new time increment provided to the automatic time
integration algorithms is PNEWDT × DTIME, where the PNEWDT used is the minimum value for all calls to user subroutines that allow redefinition of PNEWDT for this iteration.
（如果PENWD被重新定义成小于1.0的数，Abaqus/Standard必须禁止时间变量，并且尝试更小的时间变量。新的时间变量采用自动时间积分算法是PNEWDT × DTIME， PNEWDT使用最小的值对于调用其他的子程序，允许PENWDT迭代。） If PNEWDT is given a value that is greater than 1.0 for all calls to user subroutines for this iteration and the increment converges in this iteration, Abaqus/Standard may increase the time increment. The suggested new time increment provided to the automatic time integration algorithms is PNEWDT × DTIME, where the PNEWDT used is the minimum value for all calls to user subroutines for this iteration.
If automatic time incrementation is not selected in the analysis procedure, values of PNEWDT that are greater than 1.0 will be ignored and values of PNEWDT that are less than 1.0 will cause the job to terminate. (如果PENWD在所有调用的子程序中因为迭代或增量在迭代中收敛被重新定义成大于1.0的数，Abaqus/Standard可能增长时间变量。建议新的时间增量采用自动时间积分方法PNEWDT × DTIME计算，PNEWDT在迭代中采用最小值)
Variables passed in for information（传递信息的变量）
DIRECT(3,3)
An array containing the direction cosines of the material directions in terms of the global basis directions. DIRECT(1,1), DIRECT(2,1), DIRECT(3,1) give the (1, 2, 3) components of the first material direction; DIRECT(1,2), DIRECT(2,2), DIRECT(3,2) give the second material direction, etc. For shell and membrane elements, the first two directions are in the plane of the element and the third direction is the normal. This information is not available for beam elements.
（一组数据包含着材料各个方向的方向余弦。DIRECT(1,1), DIRECT(2,1), DIRECT(3,1) give the (1, 2, 3)是第一材料方向的组成成分；DIRECT(1,2), DIRECT(2,2), DIRECT(3,2) 是第二材料方向的组成成分。对于壳体和薄膜单元，第一和第二方向在平面的上面，第三方向是正常的。这个信息不能用于梁构件。） T(3,3)
An array containing the direction cosines of the material orientation components relative to the element basis directions. This is the
orientation that defines the material directions (DIRECT) in terms of the element basis directions. For continuum elements T and DIRECT are identical. For shell and membrane elements T(1,1) , T(1,2)
, T(2,1) , T(2,2) , T(3,3) , and all other
components are zero, where is the counterclockwise rotation around the normal vector that defines the orientation. If no orientation is used, T is an identity matrix. Orientation is not available for beam elements. （一组数据包含着相对于单元基本方向而言是材料导向组件的方向余弦。根据单元的基本方向，定义材料的方向（DIRECT）。连续单元T和DIRECT是相同的。对于壳体和膜单元T(1,1) , T(1,2) , T(2,1) , T(2,2)
, T(3,3) ，其他的单元为0，是绕正常向量逆时针旋转定义方向
的。如果没有方向，T是单位矩阵。定位不适用于梁单元。）
CELENT
Characteristic element length. This is a typical length of a line across an element for a first-order element; it is half of the same typical length for a second-order element. For beams and trusses it is a characteristic length along the element axis. For membranes and shells it is a characteristic length in the reference surface. For axisymmetric elements it is a characteristic length in the
plane only.
（特征元素的长度。这是对于一阶元素而言，一条直线的典型长度；对于二阶元素而言，它是典型长度的一半。对于梁和桁架结构，它是沿着元件轴线的特征长度。对于膜和壳而言，是在参考表面上的特征长度。对于轴对称元素它只是在
平面上的特征长度。） TIME(1)
Value of step time at the beginning of the current increment. （在当前增量开始时的步长的数值。） TIME(2)
Value of total time at the beginning of the current increment. （在当前增量开始时的总时间的数值。） DTIME
Time increment. （时间增量） CMNAME
User-specified material name, left justified. （用户指定的材料名称，左对齐） ORNAME
User-specified local orientation name, left justified. （用户指定的局部定向的名字，左对齐）
NFIELD
Number of field variables defined at this material point. （在这个材料点定义的字段变量的个数） NSTATV
User-defined number of solution-dependent state variables (see
“Allocating space” in “User subroutines: overview,” Section 17.1.1 of the Abaqus Analysis User's Manual). （用户定义的解相关状态变量的个数） NOEL
Element number. （单元数目） NPT
Integration point number. （集成点数量） LAYER
Layer number (for composite shells and layered solids). （层号（用于复合壳体和层状实体）） KSPT
Section point number within the current layer. （当前层内的节点数） KSTEP Step number. （时间步长） KINC