ansys.mapdl.core.Mapdl.sfbeam#

Mapdl.sfbeam(elem='', lkey='', lab='', vali='', valj='', val2i='', val2j='', ioffst='', joffst='', lenrat='', **kwargs)#

Specifies surface loads on beam and pipe elements.

Mechanical APDL Command: SFBEAM

Parameters:
elemstr

Element to which surface load is applied. If ALL, apply load to all selected beam elements ( esel ). If Elem = P, graphical picking is enabled and all remaining command fields are ignored (valid only in the GUI). A component name may be substituted in Elem.

lkeystr

Load key associated with surface load (defaults to 1). Load keys (1, 2, 3, etc.) are listed under “Surface Loads” in the input table for each element type in the Element Reference. For beam and some pipe elements, the load key defines the load orientation.

labstr

Valid surface load label. Load labels are listed under “Surface Loads” in the input table for each element type in the Element Reference. Structural labels: PRES (pressure).

valistr

Surface load values at nodes I and J. If VALJ is blank, it defaults to VALI. If VALJ is zero, a zero is used.

valjstr

Surface load values at nodes I and J. If VALJ is blank, it defaults to VALI. If VALJ is zero, a zero is used.

val2istr

Second surface load values at nodes I and J. Currently not used.

val2jstr

Second surface load values at nodes I and J. Currently not used.

ioffststr

Offset distance from node I (toward node J) where VALI is applied, and offset distance from node J (toward node I) where VALJ is applied, respectively.

joffststr

Offset distance from node I (toward node J) where VALI is applied, and offset distance from node J (toward node I) where VALJ is applied, respectively.

lenratint or str

Offset distance flag:

  • 0 - Offset is in terms of length units (default).

  • 1 - Offset is in terms of a length ratio (0.0 to 1.0).

Notes

Specifies surface loads on the selected beam elements. Distributed loads are applied on a force-per- length basis (that is, the width of the underlying element is not considered). To list and delete surface loads applied with this command, use the sfelist and sfedele commands, respectively.

If no offset values ( IOFFSET and JOFFSET ) are specified, the load is applied over the full element length. Values may also be input as length fractions, depending on the LENRAT setting. For example, assuming a line length of 5.0, an IOFFST of 2.0 with LENRAT = 0 or an IOFFST of 0.4 with LENRAT = 1 represent the same point. If JOFFST = -1, VALI is assumed to be a point load at the location specified via IOFFST, and VALJ is ignored. ( IOFFSET cannot be equal to -1.) The offset values are stepped even if you issue a kbc,0 command.

Offsets are only available for element types BEAM188 and PIPE288 if using the cubic shape function (KEYOPT(3) = 3) for those element types.

To accumulate (add) surface loads applied with this command, use the sfcum,,ADD command. Use the same offset values used on the previous sfbeam command (for a given element face); otherwise, the loads do not accumulate. If no offsets are specified, the command applies the previous offset values.

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 the lvscale command.

This command is also valid in PREP7.