Boundary Conditions

Use boundary conditions to communicate engineering assumptions about support conditions to analysis software packages.

You can apply point, line, and area boundary conditions to your analytical model. Click Analyze tab Analytical Model panel (Boundary Conditions) To access the boundary condition tools.

• Click Modify | Place Boundary Conditions tab Boundary Conditions panel
  • (Point)
  • (Line)
  • (Area)

Each boundary conditions tool has two placing options.

• Point Boundary:
  1. (On End Point) - create a point boundary condition constrained to an analytical member end point or an analytical panel corner.
  2. (Pick Position) - place a boundary condition anywhere on analytical members or panels.
• Line Boundary:
  1. (On Host) - create a line boundary condition constrained to an analytical member, on its entire length or to an analytical panel edge, on its entire length.
  2. (Define Path) - place a boundary condition anywhere on analytical members or panels.
• Area Boundary:
  1. (On Host) - create an area boundary condition for the entire surface of an analytical panel.
  2. (Define Boundary) - place a boundary condition anywhere on analytical members or panels.

Boundary Condition Host

• A boundary condition always has a host element.
• The host can be referenced.
• Changes in the host position will trigger a boundary condition position update.
• If you delete the host, the boundary condition will also be deleted.
• A boundary condition can be assigned to only one host.
• You can place boundary conditions outside the host.
  • The boundary condition will remain hosted and its behavior will not change in relation to its host.
  • A warning will be displayed for that element. The warning will disappear once this situation is solved.
• A boundary condition can be constrained to its host's end/corner/entire length/entire area, or it can have a user defined position in relation to its host. The constrain status is marked by the Is Constrained on host parameter in the specific boundary condition properties. The box for this parameter is checked by default for boundary conditions crested with the On End-Point or On Host tools. For boundary conditions created with the Pick Position, Define Path, and Define Boundary tools, the box for this parameter is unchecked.
  • To remove the constraint from a boundary condition, you can uncheck the box next to Is Constrained on host. After this, the boundary condition will behave like a boundary condition created with the Pick Position, Define Path, and Define Boundary tools. This process is not reversible, once you remove the constraint from a boundary condition you cannot constrain it back to its host, the Is Constrained on host parameter will be grayed out.

Boundary Condition Orientation

The orientation of boundary conditions is aligned to the project base point and its orientation settings.

The Y axis orientation for forces is aligned with the N/S orientation, the X axis is aligned with E/W and the Z axis is aligned with the Elevation.

Rotating the project north will change both the orientation of analytical elements and the orientation of boundary condition. If you change the orientation of the analytical elements, the position of the boundary condition will not be updated.