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18.104.22.168 Rigid_Connector_Data Class
The rigid_connector_data class defines a set of variables for each rigid joint or rigid connector. The data is stored for each rigid joint or rigid connector that is listed in the item list of the rigid_connector_data element or for all rigid connectors if no list is defined. The following variables are defined. Note that the item referenced in the item list is the rigid connector number in the order in which rigid connectors appear in the input file.
|Rigid body variables||Description|
|RCFx||x-component of rigid connector force|
|RCFy||y-component of rigid connector force|
|RCFz||z-component of rigid connector force|
|RCMx||x-component of rigid connector moment|
|RCMy||y-component of rigid connector moment|
|RCMz||z-component of rigid connector moment|
|RCx||x-component of rigid connector translation|
|RCy||y-component of rigid connector translation|
|RCz||z-component of rigid connector translation|
|RCthx||x-component of rigid connector rotation|
|RCthy||y-component of rigid connector rotation|
|RCthz||z-component of rigid connector rotation|
For example, to store the reaction forces and moments at rigid joints 2 and 4 add the following data element:
The rigid connector translation and rotation variables return relative motions of the rigid bodies connected by rigid joints and other rigid connectors (Section 3.11.2↑). The rotation components represent the components of a vector whose direction is along the axis of rotation, and whose magnitude is the (counter-clockwise) angle of rotation. These relative motions are calculated as the motion of body_b relative to body_a, expressed in the local Cartesian basis of body_a, whose initial origin is at joint_origin. This Cartesian basis (which generally moves with body_a) has its first axis along rotation_axis (for revolute and planar joints) or translation_axis (for prismatic joints) or joint_axis (for cylindrical joints); the second axis is along the transverse_axis (for revolute, prismatic and cylindrical joints) or translation_axis_1 (for planar joints). For spherical joints, springs, dampers, angular dampers and contractile forces, the axes are always aligned with the global Cartesian basis.
For springs, dampers and contractile forces, the returned translation components represent the relative position vector between insertion points on body_b and body_a. The magnitude of this vector represents the distance between those points.