Rigid Link




Constrain certain degrees-of-freedom of Slave Nodes to a Master Node.


If a degree-of-freedom of a particular slave node is constrained to a master node by this command, "Rigid Link" relationship is established for the relevant degree-of-freedom. All the attributes (nodal load or nodal mass) including the stiffness component of the slave node are converted into an equivalent component of the master node.




From the Main Menu select Boundary > Link > Rigid Link.





Click to the right of Rigid Link: Display the Rigid Link Table



 Boundary Group Name


Select a Boundary Group in which the specified boundary condition is included. Select "Default" if Group assignment is unnecessary. Click to the right to prompt the "Define Boundary Group" dialog box to add, modify or delete Boundary Groups.




Add/Replace: Assign selected nodes as slave nodes or modify rigid link conditions


Delete: Delete rigid link conditions of selected nodes



Master Node Number


Enter a master node number. Type in directly the master node number on the keyboard, or click the entry field and the relevant node.


Note that the slave nodes are assigned by Select.


Reactions of slave nodes were printed at the slave nodes.  From V690, slave node reactions are combined and printed as the vertical load and moments at the master node.


Release Slave Nodes Without Specifying Master Nodes: Release slave nodes without selecting the master node. This function can be used in the Delete option only.



DOF of Rigid Link


Assign the degree-of-freedom about GCS degree-of-freedom to be slaved to the master node.


DX: Displacement degree-of-freedom in GCS X-direction


DY: Displacement degree-of-freedom in GCS Y-direction


DZ: Displacement degree-of-freedom in GCS Z-direction


RX: Rotational degree-of-freedom about GCS X-axis


RY: Rotational degree-of-freedom about GCS Y-axis


RZ: Rotational degree-of-freedom about GCS Z-axis



Copy Rigid Link


Copy the rigid link conditions defined in DOF of the Rigid Link and simultaneously assign the identical conditions to selected nodes.


Axis: Assign the axis direction to be copied


Distances: Assign the copy distances


Nodes must exist at the location to which the Rigid Link will be copied for master and slave nodes.



Typical Types


The following buttons simplify the individual data entries described above.


: Rigid Body Connection


: Rigid Plane Connection in GCS X-Y plane


: Rigid Plane Connection in GCS Y-Z plane


: Rigid Plane Connection in GCS X-Z plane



Revision of Gen 2015 (v1.1)


Q1. If the horizontal and vertical link assembly is changed to inclined link assembly, the vertical reactions change. Why ?