sfl

SolidSurfaceLoads.sfl(line='', lab='', vali='', valj='', val2i='', val2j='', **kwargs)

Specifies surface loads on lines of an area.

Mechanical APDL Command: SFL

Parameters:

linestr

Line to which surface load applies. If ALL, apply load to all selected lines ( lsel ). If Line = P, graphical picking is enabled and all remaining command fields are ignored (valid only in the GUI). A component name may be substituted for Line.

labstr

Valid surface load label. Load labels are listed under “Surface Loads” in the input table for each element type in the Element Reference. This command contains some tables and extra information which can be inspected in the original documentation pointed above… _sfl1:

Thermal labels CONV and HFLUX are mutually exclusive.

For an acoustic analysis, apply the fluid-structure interaction flag (Label = FSI) to only the FLUID129 or FLUID130 elements.

valistr

Surface load values at the first keypoint ( VALI ) and at the second keypoint ( VALJ ) of the line, or table name for specifying tabular boundary conditions. If VALJ is blank, it defaults to VALI. If VALJ is zero, a zero is used.

If Lab = CONV:

• VALI and VALJ are the film coefficients and VAL2I and VAL2J are the bulk temperatures.

• To specify a table, enclose the table name in percent signs (%), e.g., tabname. (Issue dim to define a table.)

• If Lab = CONV and VALI = - N, the film coefficient may be a function of temperature and is determined from the HF property table for material N ( mp ). (See scopt for a way to override this option and use - N as the film coefficient.)

• If kbc,0 has been issued for ramped loads, it affects only the bulk temperatures, VAL2I and VAL2J, and the film coefficient specification, VALI and VALJ, are unaffected.

If Lab = RAD, VALI and VALJ values are surface emissivities and VAL2I and VAL2J are ambient temperatures. The temperature used to evaluate the film coefficient is usually the average between the bulk and wall temperatures, but may be user-defined for some elements.

If Lab = RDSF, VALI is the emissivity value. If VALI = -N, the emissivity may be a function of the temperature and is determined from the EMISS property table for material N ( mp ).

If Lab = FSIN in a unidirectional Mechanical APDL-to-CFX analysis, VALJ is the surface interface number (not available from within the GUI) and VALI is not used.

valjstr

Surface load values at the first keypoint ( VALI ) and at the second keypoint ( VALJ ) of the line, or table name for specifying tabular boundary conditions. If VALJ is blank, it defaults to VALI. If VALJ is zero, a zero is used.

If Lab = CONV:

• VALI and VALJ are the film coefficients and VAL2I and VAL2J are the bulk temperatures.

• To specify a table, enclose the table name in percent signs (%), e.g., tabname. (Issue dim to define a table.)

• If Lab = CONV and VALI = - N, the film coefficient may be a function of temperature and is determined from the HF property table for material N ( mp ). (See scopt for a way to override this option and use - N as the film coefficient.)

• If kbc,0 has been issued for ramped loads, it affects only the bulk temperatures, VAL2I and VAL2J, and the film coefficient specification, VALI and VALJ, are unaffected.

If Lab = RAD, VALI and VALJ values are surface emissivities and VAL2I and VAL2J are ambient temperatures. The temperature used to evaluate the film coefficient is usually the average between the bulk and wall temperatures, but may be user-defined for some elements.

If Lab = RDSF, VALI is the emissivity value. If VALI = -N, the emissivity may be a function of the temperature and is determined from the EMISS property table for material N ( mp ).

If Lab = FSIN in a unidirectional Mechanical APDL-to-CFX analysis, VALJ is the surface interface number (not available from within the GUI) and VALI is not used.

val2istr

Second surface load values (if any). If VAL2J is blank, it defaults to VAL2I. If VAL2J is zero, a zero is used. To specify a table ( Lab = CONV), enclose the table name in percent signs (%), for example, tabname. Use the dim command to define a table.

If Lab = CONV:

• VAL2I and VAL2J are the bulk temperatures.

• If kbc,0 has been issued for ramped loads, the bulk temperature is ramped from the value defined by tunif to the value specified by VALI and VALJ for the first loadstep. If tabular boundary conditions are defined, the kbc command is ignored and tabular values are used for the bulk temperatures.

If Lab = RAD, VAL2I and VAL2J are the ambient temperatures.

If Lab = RDSF, VAL2I is the enclosure number. Radiation will occur between surfaces flagged with the same enclosure numbers. If the enclosure is open, radiation will occur to the ambient.

VAL2I and VAL2J are not used for other surface load labels.

val2jstr

Second surface load values (if any). If VAL2J is blank, it defaults to VAL2I. If VAL2J is zero, a zero is used. To specify a table ( Lab = CONV), enclose the table name in percent signs (%), for example, tabname. Use the dim command to define a table.

If Lab = CONV:

• VAL2I and VAL2J are the bulk temperatures.

• If kbc,0 has been issued for ramped loads, the bulk temperature is ramped from the value defined by tunif to the value specified by VALI and VALJ for the first loadstep. If tabular boundary conditions are defined, the kbc command is ignored and tabular values are used for the bulk temperatures.

If Lab = RAD, VAL2I and VAL2J are the ambient temperatures.

If Lab = RDSF, VAL2I is the enclosure number. Radiation will occur between surfaces flagged with the same enclosure numbers. If the enclosure is open, radiation will occur to the ambient.

VAL2I and VAL2J are not used for other surface load labels.

Notes

Specifies surface loads on the selected lines of area regions. The lines represent either the edges of area elements or axisymmetric shell elements themselves. Surface loads may be transferred from lines to elements via sftran or sbctran. See sfe for a description of surface loads. Loads input on this command may be tapered. See sfgrad for an alternate tapered load capability.

You can specify a table name only when using structural (PRES) and thermal (CONV [film coefficient and/or bulk temperature], HFLUX), and surface emissivity and ambient temperature (RAD) surface load labels. VALJ and VAL2J are ignored for tabular boundary conditions.

In a mode-superposition harmonic or transient analysis, you must apply the load in the modal portion of the analysis. Mechanical APDL calculates a load vector and writes it to the MODE file, which you can apply via lvscale.

This command is also valid in PREP7.