Function
- Create or remove elastic links. Two nodes are connected by an elastic link and its stiffness is defined by the user.
Call
From the main menu, select [Boundary] tab > [Links] group > [Elastic Link]
Input
The right ... of Elastic Link
Display Elastic 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.
Options
Add : Enter or replace elastic links
Delete : Delete previously entered elastic links
Elastic Link Data
Link Type : Assign an elastic link type.
General Type : General elastic link (6dof)
Rigid Type : The rigid connection element is assigned a stiffness equal to 1e5 times the stiffness of the largest stiffness component in the stiffness matrix.
In case of Rigid Type, the link stiffness is automatically calculated based on the working model. The applied stiffness of the link can be checked in the text output file (*.out) after performing analysis.
Tens.-only : Tension-only elastic link
Comp.-only : Compression-only elastic link
When an elastic link is assigned as tension-only or compression-only, only element's axial stiffness can be applied. The elastic link observes the Iteration method defined in Main Control Data identical to tension- and compression-only.
Multi-Linear : Multi-linear elastic link
SDx : Stiffness in the link's local x-direction
SDy : Stiffness in the link's local y-direction
SDz : Stiffness in the link's local z-direction
SRx : Rotational stiffness about the link's local x-axis
SRy : Rotational stiffness about the link's local y-axis
SRz : Rotational stiffness about the link's local z-axis
Shear Spring Location
Save the locations of shear springs used in elastic links.
Distance Ratio From End I
Specify the locations of the shear springs relative to the length of the elastic links starting from i-node.
Beta Angle : Angle defining the elastic link orientation
Saddle : In a multi-span suspension bridge, top tower saddle can be shifted relative to the tower before starting the cable erection. Top tower saddle can be simulated using Elastic Link: saddle type.
2 Nodes
Enter the node numbers for the 2 nodes to be elastically linked.
Copy Elastic Link
Define simultaneously a number of elastic links by copying the conditions assigned to an elastic link.
Node Inc.
Create a number of elastic link elements using a node increment.
Number of Times : Number of copies
Node Increment : Increment of node numbers
Distance
Create a number of elastic link elements using the distances between nodes.
Axis : Assign an axis direction for copying the elastic link.
Distances : Enter the number of repetitions and/or distances for copying the elastic link.
Type : Multi-Linear
Multi-Linear elastic link
Multi-Linear Type : Allows the input of tensile and compressive stiffness of the link element in a symmetric or asymmetric manner.
Compression is considered as a positive displacement for the spring. Therefore, the stiffness represented in the first quadrant of the diagram indicates the stiffness when compression is applied to the link.
Direction : Defines the multi-linear elastic connection element based on the element coordinate system.
The slope is maintained between the outermost two points for the external segments that are not explicitly defined by the user.