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.

Select Geometry > Boundaries > Rigid Link in the Menu tab of the Tree Menu.



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.


DOF of Rigid Link

Assign the degrees-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


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

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.


Revision of Civil 2015 (v1.1)

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