Initial Values (Rigid Domain)
The Initial Values subnode is automatically added when you select that the initial values in a Rigid Domain node are Locally defined.
You can enter initial values for the rigid body displacement, rotation and velocities, which can serve as an initial condition for a transient simulation or as an initial guess for a nonlinear analysis. The initial values that you specify are interpreted in the selected coordinate system.
Center of Rotation
Select an option from the list: From parent, Centroid of selected entities, or User defined. The given initial values are interpreted at the center of rotation.
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For From parent, the center of rotation is taken as the one defined in the parent Rigid Domain node.
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For Centroid of selected entities select an Entity level — Boundary, Edge, or Point. The available choices depend on geometrical dimension. The initial conditions act at the centroid of the selected entities, which do not need to be related to rigid domain itself. As a special case, you can select a single point and thus prescribe the initial conditions at that point.
When chosen, a default Center of Rotation: Boundary, Center of Rotation: Boundary, or Center of Rotation: Point subnode is automatically added.
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For User defined, enter the Global coordinates of center of rotation, Xc, in the table.
Select the Offset check box to add an optional offset vector to the definition of the center of rotation. Enter values for the offset vector Xoffset.
The center of rotation used is the sum of the vector obtained from any of the input methods and the offset vector.
Initial Values: Translational
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Displacement at center of rotation u.
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Velocity at center of rotation ∂u/∂t.
Initial Values: Rotational
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For 3D components only: Axis of rotation Ω
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Angle of rotation .
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Angular velocity ω (3D components) and (2D components)
Location in User Interface
This node is automatically added when Locally defined is selected in the Initial Values section in the parent Rigid Domain node. It cannot be added or removed manually.