BF, Node, Lab, VAL1, VAL2, VAL3, VAL4, VAL5, VAL6
Defines a nodal body force load.
NodeNode to which body load applies. If Node = ALL, apply to all selected nodes [NSEL]. A component name may also be substituted for Node.
LabValid body load label. Load labels are listed under "Body Loads" in the input table for each element type in the Element Reference.
| Discipline | Body Load Label | Label Description |
|---|---|---|
| Structural | TEMP | Temperature |
| FREQ | Frequency (harmonic analyses only) | |
| FLUE | Fluence | |
| FPBC | Floquet periodic boundary condition | |
| Thermal | HGEN | Heat generation rate (updated by volume changes when large-deflection effects are included [NLGEOM,ON]) |
| Magnetic | TEMP | Temperature |
| VELO | Velocity or angular velocity | |
| MVDI | Magnetic virtual displacements flags | |
| Electric | TEMP | Temperature |
| CHRGD | Charge density | |
| Acoustic | MASS | Mass source or mass source rate |
| IMPD | Impedance sheet | |
| SPRE | Static pressure | |
| TEMP | Temperature | |
| VELO | Velocity or acceleration | |
| PORT | Interior acoustics port | |
| FPBC | Floquet periodic boundary condition | |
| VMEN | Mean flow velocity | |
| Poromechanics | FSOU | Fluid flow source |
| Diffusion | TEMP | Temperature |
| DGEN | Diffusing substance generation rate | |
| VELO | Transport velocity |
VAL1, VAL2, VAL3, VAL4, VAL5, VAL6Value associated with the Lab item or table
name reference for tabular boundary conditions. Use only VAL1
for TEMP, FLUE, HGEN, DGEN, MVDI, CHRGD, PORT, and SPRE.
Tabular input is supported for certain labels (see Notes for details). To specify a table, enclose the table
name in percent signs (%) (e.g.,
BF,Node,TEMP,%tabname%). Use the *DIM command to define a table.
If Lab = MASS for acoustics:
| — | Mass source with units kg/(m3s) in a harmonic analysis, or mass source rate with units kg/( m3s2) in a transient analysis |
| — | Phase angle in degrees |
| — | Not used |
| — | Not used |
| — | Not used |
| — | Not used |
If Lab = VELO for acoustics (velocity
components in harmonic analysis or acceleration components in a transient
analysis):
| — | X component |
| — | Y component |
| — | Z component |
| — | X-component phase angle in degrees |
| — | Y-component phase angle in degrees |
| — | Z-component phase angle in degrees |
If Lab = VELO for electromagnetics
(velocity and angular velocity components in the global Cartesian
coordinate system):
| — | Velocity component in the X direction |
| — | Velocity component in the Y direction |
| — | Velocity component in the Z direction |
| — | Angular velocity about the X axis (rad/sec) |
| — | Angular velocity about the Y axis (rad/sec) |
| — | Angular velocity about the Z axis (rad/sec) |
If Lab = VELO for diffusion
(transport velocity):
| — | Transport velocity component in X direction |
| — | Transport velocity component in Y direction |
| — | Transport velocity component in Z direction |
| — | Not used |
| — | Not used |
| — | Not used |
If Lab = IMPD:
| — | Resistance in N⋅s/m3 |
| — | Reactance in N⋅s/m3 |
| — | Not used |
| — | Not used |
| — | Not used |
| — | Not used |
If Lab = FPBC:
| — | Phase shift (product of phase constant and period in unit radian); or Floquet boundary flag
(set |
| — | Attenuation (product of attenuation constant and period); not used if
|
| — | Not used |
| — | Not used |
| — | Not used |
| — | Not used |
If Lab = VMEN:
| — | Mean flow velocity component in the X direction |
| — | Mean flow velocity component in the Y direction |
| — | Mean flow velocity component in the Z direction |
| — | Not used |
| — | Not used |
| — | Not used |
Defines a nodal body force load (such as temperature in a structural analysis, heat generation rate in a thermal analysis, etc.). Nodal body loads default to the BFUNIF values, if they were previously specified.
Table names are valid for Lab value
(VALn) inputs in these cases only:
VAL1 = %tabname% for temperatures (TEMP), diffusing substance generation rates
(DGEN), and heat generation rates (HGEN).
VAL1 = %tabname1%, VAL2 =
%tabname2%, VAL3 = %tabname3%, VAL4 = %tabname4%, VAL5 = %tabname5%, and VAL6 = %tabname6% for velocities or accelerations (VELO).
VAL1 = %tabname1% and
VAL2 = %tabname2% for mass sources
or mass source rates (MASS), and the Floquet periodic boundary condition (FPBC).
VAL1 = %tabname1%,
VAL2 = %tabname2%, and
VAL3 = %tabname3% for mean flow
velocities (VMEN).
The heat generation rate loads specified with the BF command are multiplied by the weighted nodal volume of each element adjacent to that node. This yields the total heat generation at that node.
In a modal analysis, the Floquet periodic boundary condition (FPBC) is only valid for the acoustic elements FLUID30, FLUID220, and FLUID221.
Graphical picking is available only via the listed menu paths.
Body load labels VELO, MASS, SPRE, FPBC, and VMEN cannot be accessed from a menu.
This command is also valid in PREP7.