Moving Frame Boundary Condition
If the physics interface controls the deformation of the material or the spatial frame, use the Moving Frame Boundary Condition node () to specify the boundary conditions for domains with Free frame motion. See the Moving Frame Domain Condition section for details. The physics interface controls the frame deformation if the Deformed mesh check box in the physics interface node is selected.
The available boundary conditions are:
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No displacement: Specify that there is no displacement.
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 Displacement (the default): Specify the Displacement vector at the boundary as a 3-component vector.
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 Componentwise displacement: Choose which components of the displacement to constrain by using the Constrain displacement in direction 1/2/3 check boxes. Then specify the expressions for the appropriate Displacement component 1/2/3. Use the Input Dependency subnode to make these specification dependent on other user inputs.
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 Normal displacement: Specify the expression of the normal displacement of the boundary. A positive displacement is in the direction of the normal from downside (root.dn).
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Zero normal displacement: Specify that there is no displacement in the normal direction.
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 Velocity (the default): Specify the Velocity vector at the boundary as a 3-component vector. This condition is only applicable for Transient studies.
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 Componentwise velocity: Choose which components of the velocity to constrain by using the Constrain velocity in direction 1/2/3 check boxes. Then specify the expressions for the appropriate Velocity component 1/2/3. Use the Input Dependency subnode to make these specification dependent on other user inputs. This condition is only applicable for Transient studies.
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 Normal velocity: Specify the expression of the normal displacement of the boundary. A positive displacement is in the direction of the normal from downside (root.dn). This condition is only applicable for Transient studies. The Normal velocity condition can also support Boundary smoothing by selecting the check box.
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Zero normal velocity: Specify that there is no velocity in the normal direction.
Weak constraints can be used for certain conditions, according to the value selected in the Use weak constraint list. If Yes is selected, weak constraints will be always used. If No is selected, weak constraints will never be used. If From constraints settings is selected (the default), the settings in the feature’s Constraint Settings Section will determine if weak constraints are to be used, defaulting to No if the section does not exist.
Use the Selection section to specify the selection on which to apply the boundary condition. The selection must be adjacent to a selection with Free frame motion, and (except for very particular cases) boundary conditions must be specified for all Free domain selections in order to obtain a well-posed problem.