Rigid Motion Models Reference

To specify the details of a rigid motion, you define the properties of the relevant motion model node. The Rotation, Translation, Rotation and Translation, and Trajectory nodes, that are added under the Tools node, have specific properties and share some common properties.

For more information on how to use these models in a simulation, see Prescribing Rigid Rotations and Translations and Prescribing Motion along a Specified Trajectory.

Common Properties

Coordinate System: Specifies the coordinate system (laboratory by default) in which you define the relevant motion properties (for example, the rotation axis in a rotation motion or the translation velocity in a translation motion).
Managed Coordinate Systems: Specifies coordinate systems that the motion is to move. When you add superposed motions to an existing motion, the local coordinate system for the superposed motion is automatically created and added to the Managed Coordinate Systems property of the parent motion.

Rotation Motion Properties

This type of motion supports superposing rotations and translations. See Superposing Rotations on a Trajectory Motion.

Rotation Specification

Provides several methods for defining the rotation motion:

Method	Corresponding Child Nodes
Rotation Rate	Rotation Rate Specifies the rotation rate around the rotation axis as a scalar quantity. The rotation rate can either be a constant value or a space-invariant expression. Rotation Axis Defines a rotation axis by specifying Direction and Origin with respect to the Coordinate System of the [rotation] node.
Rotation Angle	Rotation Angle Specifies the angle spanned around the rotation axis as a function of time. Rotation Axis Defines a rotation axis by specifying Direction and Origin with respect to the Coordinate System of the [rotation] node.
Angular Velocity	Angular Velocity Specifies three angular velocity components defined in the Coordinate System of the [rotation] node. Rotation Origin You define the center of rotation by specifying Origin.
Euler Angles	Euler Angles Specifies Euler angles, which describe the change in orientation of the body with respect to its original orientation. Before setting the values of the Euler angles, you must specify the order of Euler rotations through Euler Angle Convention. The axes here are defined in the Coordinate System of the [rotation] node. Euler Angle X, Euler Angle Y, and Euler Angle Z then provide the orientation of the body as functions of time. Rotation Origin You define the center of rotation by specifying Origin.

Coordinate System

Specifies the coordinate system with respect to which the motion properties are defined.

Managed Coordinate Systems

Displays the coordinate systems that move together with the defined rotation. The origin of a managed coordinate system represents a point fixed on the rotating body.

Translation Motion Properties

This type of motion supports superposing rotations and translations. See Superposing Motions.

Translation Velocity: Specifies the translation velocity vector with respect to the selected Coordinate System.

Rotation and Translation Motion Properties

This type of motion does not support superposing motions.

Axis Direction: Specifies the direction vector that defines the axis of rotation. The direction is specified with respect to the coordinate system selected in the Coordinate System property.
Axis Origin: Specifies the position vector that defines the origin of the axis of rotation, with respect to the selected Coordinate System.
Rotation Rate: Specifies the rotation rate around the axis defined by the Axis Direction and Axis Origin. This option is additive with Translation Velocity.
Translation Velocity: Specifies the translation velocity vector with respect to the selected Coordinate System.

Trajectory Motion Properties

This type of motion supports superposing rotations and translations. See Superposing Rotations on a Trajectory Motion.

Method

Specifies the method that is used to define the trajectory. Depending on the selected method, you specify the trajectory on a child node of the Trajectory motion node.

Method	Corresponding Child Nodes
Table(x,y,z) Defines the trajectory by providing a table of coordinates. To define the motion along the trajectory as a function of time, you also provide either the displacement or the velocity of the region as a function of time.	Table(x,y,z) Allows you to provide a 3-column table containing the $x, y, z$ coordinates that define the trajectory. To specify the method for providing the time dependence, set Speed Specification to either Velocity Function or Displacement Function. [Velocity/Displacement] Function Depending on the selected Speed Specification, allows you to select the time-dependent field function that defines either the velocity or the displacement.
Table(time,x,y,z) Defines the trajectory by providing a table of coordinates and time values.	Table(time,x,y,z) Allows you to provide a 4-column table containing the discrete time values and the corresponding $x, y, z$ coordinates.

Method

Corresponding Child Nodes

Table(x,y,z): Defines the trajectory by providing a table of coordinates. To define the motion along the trajectory as a function of time, you also provide either the displacement or the velocity of the region as a function of time.

Table(x,y,z): Allows you to provide a 3-column table containing the $x, y, z$ coordinates that define the trajectory. To specify the method for providing the time dependence, set Speed Specification to either Velocity Function or Displacement Function.
[Velocity/Displacement] Function: Depending on the selected Speed Specification, allows you to select the time-dependent field function that defines either the velocity or the displacement.

Table(time,x,y,z): Defines the trajectory by providing a table of coordinates and time values.

Table(time,x,y,z): Allows you to provide a 4-column table containing the discrete time values and the corresponding $x, y, z$ coordinates.