Product: ABAQUS/Standard
User subroutine UFLUIDLEAKOFF:
can be used to define the fluid leak-off coefficients for pore pressure cohesive elements;
is called at all material calculation points of elements for which the material definition contains user-defined leak-off coefficients; and
can include material behavior dependent on field variables or state variables.
SUBROUTINE UFLUIDLEAKOFF(PERM,PGRAD,DN,P_INT,P_BOT,P_TOP,
1 ANM,TANG,TIME,DTIME,TEMP,DTEMP,PREDEF,DPRED,C_BOT,C_TOP,
2 DC_BOT,DC_TOP,STATEV,NSTATV,NOEL,NPT,KSTEP,KINC)
C
INCLUDE 'ABA_PARAM.INC'
C
CHARACTER*80 CMNAME
DIMENSION PERM(2),PGRAD(2),ANM(3),TANG(3,2),TIME(2),PREDEF(1),
1 DPRED(1),DC_BOT(3),DC_TOP(3),STATEV(NSTATV)
user coding to define C_BOT, C_TOP, DC_BOT, and DC_TOP
RETURN
ENDC_BOT
, fluid leak-off coefficient on the bottom side of a pore pressure cohesive element.
C_TOP
, fluid leak-off coefficient on the top side of a pore pressure cohesive element.
DC_BOT(1)
, where d=DN.
DC_BOT(2)
, where 
=P_INT.
DC_BOT(3)
, where 
=P_BOT.
DC_TOP(1)
, where d=DN.
DC_TOP(2)
, where =P_INT.
DC_TOP(3)
, where 
=P_TOP.
STATEV(NSTATV)
An array containing the values of the solution-dependent state variables. You define the meaning of these variables. These are passed in as the values at the beginning of the increment and must be returned as the values at the end of the increment. The size of the array is defined as described in “Allocating space” in “User subroutines: overview,” Section 13.2.1 of the ABAQUS Analysis User's Manual.
PERM(1)
Fluid permeability.
PERM(2)
The derivative of fluid permeability with regard to the opening.
PGRAD(1)
The first component of internal pressure gradient.
PGRAD(2)
The second component of internal pressure gradient.
DN
The relative opening of the element.
P_INT
Internal pressure.
P_BOT
Bottom pressure.
P_TOP
Top pressure.
ANM
Normal vector directed from the bottom face toward the top face.
TANG
Tangent direction vectors.
TIME(1)
Value of step time at the beginning of the current increment.
TIME(2)
Value of total time at the beginning of the current increment.
DTIME
Time increment.
TEMP
Temperature at the start of the increment.
DTEMP
Increment of temperature.
PREDEF
Array of interpolated values of predefined field variables at this point at the start of the increment, based on the values read in at the nodes.
DPRED
Array of increments of predefined field variables.
NSTATV
Number of solution-dependent state variables that are associated with this material type (defined as described in “Allocating space” in “User subroutines: overview,” Section 13.2.1 of the ABAQUS Analysis User's Manual).
NOEL
Element number.
NPT
Integration point number.
KSTEP
Step number.
KINC
Increment number.