vdrag

Mapdl.vdrag(na1='', na2='', na3='', na4='', na5='', na6='', nlp1='', nlp2='', nlp3='', nlp4='', nlp5='', nlp6='', **kwargs)

Generate volumes by dragging an area pattern along a path.

APDL Command: VDRAG

Parameters:

na1, na2, na3, … , na6

List of areas in the pattern to be dragged (6 maximum if using keyboard entry). If NA1 = ALL, all selected areas will be swept along the path. A component name may also be substituted for NA1.

nlp1, nlp2, nlp3, … , nlp6

List of lines defining the path along which the pattern is to be dragged (6 maximum if using keyboard entry). Must be a continuous set of lines. To be continuous, adjacent lines must share the connecting keypoint (the end keypoint of one line must also be first keypoint of the next line).

Returns:

str

MAPDL command output.

Return type:

str

Notes

Generates volumes (and their corresponding keypoints, lines, and areas) by sweeping a given area pattern along a characteristic drag path. If the drag path consists of multiple lines, the drag direction is determined by the sequence in which the path lines are input (NLP1, NLP2, etc.). If the drag path is a single line (NLP1), the drag direction is from the keypoint on the drag line that is closest to the first keypoint of the given area pattern to the other end of the drag line.

The magnitude of the vector between the keypoints of the given pattern and the first path keypoint remains constant for all generated keypoint patterns and the path keypoints. The direction of the vector relative to the path slope also remains constant so that patterns may be swept around curves. Lines are generated with the same shapes as the given pattern and the path lines.

Keypoint, line, area, and volume numbers are automatically assigned (beginning with the lowest available values [NUMSTR]). Adjacent lines use a common keypoint, adjacent areas use a common line, and adjacent volumes use a common area. For best results, the entities to be dragged should be orthogonal to the start of the drag path. Drag operations that produce an error message may create some of the desired entities prior to terminating.

If element attributes have been associated with the input area via the AATT command, the opposite area generated by the VDRAG operation will also have those attributes (i.e., the element attributes from the input area are copied to the opposite area). Note that only the area opposite the input area will have the same attributes as the input area; the areas adjacent to the input area will not.

If the input areas are meshed or belong to a meshed volume, the area(s) can be extruded to a 3-D mesh. Note that the NDIV argument of the ESIZE command should be set before extruding the meshed areas. Alternatively, mesh divisions can be specified directly on the drag line(s) (LESIZE). See the Modeling and Meshing Guide for more information.

You can use the VDRAG command to generate 3-D interface element meshes for elements INTER194 and INTER195. When generating interface element meshes using VDRAG, you must specify the line divisions to generate one interface element directly on the drag line using the LESIZE command. The source area to be extruded becomes the bottom surface of the interface element. Interface elements must be extruded in what will become the element’s local x direction, that is, bottom to top.

Examples

Create a square with a hole in it and drag it along an arc.

>>> anum0 = mapdl.blc4(0, 0, 1, 1)
>>> anum1 = mapdl.blc4(0.25, 0.25, 0.5, 0.5)
>>> aout = mapdl.asba(anum0, anum1)
>>> k0 = mapdl.k("", 0, 0, 0)
>>> k1 = mapdl.k("", 1, 0, 1)
>>> k2 = mapdl.k("", 1, 0, 0)
>>> l0 = mapdl.larc(k0, k1, k2, 2)
>>> output = mapdl.vdrag(aout, nlp1=l0)
>>> print(output)
DRAG AREAS
  3,
ALONG LINES
  9