DA
DA, AREA, Lab, Value1, Value2
Defines degree-of-freedom constraints on areas.
AREAArea on which constraints are to be specified. If ALL, apply to all selected areas (ASEL). If
AREA= P, graphical picking is enabled and all remaining command fields are ignored (valid only in the GUI). A component name may also be substituted forAREA.LabSymmetry label (see 1 below):
SYMM
—
Generate symmetry constraints. Requires no
Value1orValue2.ASYM
—
Generate antisymmetry constraints. Requires no
Value1orValue2.Mechanical APDL degree-of-freedom labels:
UX
—
Displacement in X direction.
UY
—
Displacement in Y direction.
UZ
—
Displacement in Z direction.
ROTX
—
Rotation about X axis.
ROTY
—
Rotation about Y axis.
ROTZ
—
Rotation about Z axis.
HDSP
—
Hydrostatic pressure.
PRES
—
Pressure.
TEMP, TBOT, TE2, TE3, . . ., TTOP
—
Temperature.
MAG
—
Magnetic scalar potential (see 2 below).
VOLT
—
Electric scalar potential (see 3 below).
AZ
—
Magnetic vector potential in Z direction (see 4 below).
CONC
—
Concentration.
ALL
—
Applies all appropriate degree-of-freedom labels except HDSP.
Footnotes for
Lab:Symmetry and antisymmetry constraints are generated as described for the DSYM command.
If
Lab= MAG andValue1= 0, this sets the flux-normal condition for the magnetic scalar potential formulations (MSP) (A flux-parallel condition is the natural boundary condition for MSP.)If
Lab= VOLT andValue1= 0, the J-normal condition is set (current density (J) flow normal to the area). (A J-parallel condition is the natural boundary condition.)For elements SOLID236 and SOLID237, if
Lab= AZ andValue1= 0, this sets the flux-parallel condition for the edge formulation. (A flux-normal condition is the natural boundary condition.) Do not use the DA command to set the edge-flux degree of freedom, AZ to a nonzero value.
Value1Value of degree of freedom or table name reference on the area. Valid for all degree-of-freedom labels. To specify a table, enclose the table name in % signs (for example, DA,
AREA,TEMP,%tabname%). Use the *DIM command to define a table.Value2For MAG and VOLT degrees of freedom:
Value of the imaginary component of the degree of freedom.
Notes
You can transfer constraints from areas to nodes via DTRAN or SBCTRAN. See DK for information about generating other constraints on areas.
Tabular boundary conditions (VALUE = %tabname%) are available only for the following degree-of-freedom labels: Electric
(VOLT), Structural (UX, UY, UZ, ROTX, ROTY, ROTZ), Acoustic (PRES, UX, UY, UZ), and temperature
(TEMP, TBOT, TE2, TE3, . . ., TTOP).
Constraints specified by the DA command can conflict with other specified constraints. See Resolution of Conflicting Constraint Specifications\ in the Basic Analysis Guide for details.
This command is also valid in PREP7.