Issue:

I am trying to run a simulation with multiple tie constraints and received the error:

"Node number # is tied twice in the connection list at position # and #."

Applies to:

• Simulation

Cause:

A node is being tied twice from the two different Tie Constraints. A node can only have one Tie Constraint acting on it so that it knows how to behave in the simulation.

Solution:

Determine which node is tied twice and adjust the FE boundaries of the Tie Constraints so that the node is only tied once.

To find out which node it is: 

• • Open up the properties of the first Tie Constraint
  • Expand the Dependent Region
    • Expand Nodes
      • Look for Node #(if you can't find it, expand the Independent Region instead)
      • Once found, drag the chip into the Notebook.

This allows you to see the node that is being used in both Tie Constraints. An example of this is below:

​

Once you know which node is being used twice, you need to edit the FE Boundary of one of the Tie Constraints to make sure the node is only tied once. 

Once you adjust the FE Boundary your simulation should run as expected.

More on this topic:

• How to run a static analysis
• Methods for connecting multiple FE meshes in an FE model
• How to create an FE Model for a simple shell lattice