Particle BC Shape Commands

These commands define shapes. All particles contained within the shape will be assigned boundary conditions for load, traction, heat flux, and concentration flux that are specified within the shape command.

Line (2D or Axisymmetric)

The command to select a line through a 2D mesh in scripted files is:

LoadLine (x1),(y1),(x2),(y2),<(tolerance)>
  (one or more load, traction, heat flux, or concentration flux condition)
    ...
EndLoadLine

In XML files, a line is selected with:

<BCLine units='(units)' x1='(x1)' y1='(y1)' x2='(x2)' y2='(y2)' tolerance='(tolerance)'>
  (one or more load, traction, heat flux, or concentration flux condition)
    ...
</BCLine>

where

• (x1, y1) to (x2, y2) define (x, y) coordinates for the points at the beginning and end of the line (or (R, Z) coordinates if axisymmetric). The units are length units (or determined by a units attribute in XML files). In XML files, the coordinates can alternatively be specified relative to the mesh edges.
• (tolerance) is an optional tolerance. The units are length units (or determined by a units attribute in XML files). In XML files, you can optionally use the format '*0.5' to set the tolerance to any factor times the minimum cell dimension in the current mesh. If it is omitted, the tolerance will be set to a small number appropriate for the current background grid cell dimensions.

This command will apply load, traction, heat flux, and/or concentration flux boundary conditions to all particles within (tolerance) of the line from (x1, y1) to (x2, y2).

Arc (2D or Axisymmetric)

The command to select an arc through a 2D mesh in scripted files is:

LoadArc (x1),(y1),(x2),(y2),(startAng),(endAng),<(tolerance)>
  (one or more load, traction, heat flux, or concentration flux condition)
    ...
EndLoadArc

In XML files, a line is selected with:

<BCArc units='(units)' x1='(x1)' y1='(y1)' x2='(x2)' y2='(y2)'
       start='(startAng)' end='(endAng)' tolerance='(tolerance)'>
  (one or more load, traction, heat flux, or concentration flux condition)
    ...
</BCLine>

where

• (x1, y1) to (x2, y2) define (x, y) coordinates for the corners of a rectangular area enclosing the arc (or (R, Z) coordinates if axisymmetric). The units are length units (or determined by a units attribute in XML files). In XML files, the coordinates can alternatively be specified relative to the mesh edges.
• (startAng) and (endAng) give the start and end angle (in degrees) to specify the arc.
• (tolerance) is an optional tolerance. The units are length units (or determined by a units attribute in XML files). In XML files, you can optionally use the format '*0.5' to set the tolerance to any factor times the minimum cell dimension in the current mesh. If it is omitted, the tolerance will be set to a small number appropriate for the current background grid cell dimensions.

This command will apply load, traction, heat flux, and/or concentration flux boundary conditions to all particles within (tolerance) of the arc. The arc is traced in a counter-clockwise direction from (startAng) to (endAng) with angle = 0 corresponding to the position along the positive x axis.

Rectangle (2D or Axisymmetric)

The command to select rectangle in a 2D mesh in scripted files is:

LoadRect (xmin),(xmax),(ymin),(ymax)
  (one or more load, traction, heat flux, or concentration flux condition)
    ...
EndLoadRect

In XML files, a rectangle is selected with:

<LdRect xmin='(xmin)' xmax='(xmax)' ymin='(ymin)' ymax='(ymax)'>
  (one or more load, traction, heat flux, or concentration flux condition)
    ...
</LdRect>

• (xmin), (xmax), (ymin), and (xmax)define the x and y ranges for the rectangular area (or R and Z ranges if axisymmetric). The units are length units (or determined by an optional units attribute in XML files). In XML files, the coordinates can alternatively be specified relative to the mesh edges.

This command will apply load, traction, heat flux, and/or concentration flux boundary conditions to all particles within the rectangle.

Box or Cylinder (3D)

The command to select a 3D box or cylinder in scripted files is:

LoadBox (x1),(y1),(z1),(x2),(y2),(z2),<(axis)>
  (one or more load, traction, heat flux, or concentration flux condition)
    ...
EndLoadBox

In XML files, a box is selected with:

<BCBox units='(units)' xmin='(x1)' xmax='(x2)' ymin='(y1)' ymax='(y2)'
                       zmin='(z1)' zmax='(z2)' axis='(axis)'>
  (one or more load, traction, heat flux, or concentration flux condition)
    ...
</BCBox>

where

• (x1, y1, z1) and (x2, y2, z2) define (x, y, z) coordinates for opposite corners of the box. The units are length units (or determined by a units attribute in XML files). In XML files, the coordinates can alternatively be specified relative to the mesh edges.
• (axis) is an optional parameter that will convert the shape from a box to the cylinder enclosed within the box with its axis along the specified direction (entered as x, 1, y, 2, z, or 3).

This command will apply load, traction, heat flux, and/or concentration flux boundary conditions to all particles within the specified box or cylinder.