Assign Node Connectivity

The engineer can assign any node to be connected or disconnected from the diaphragm by selecting the Assign - Nodes - Diaphragm Connection command. From the dialog that appears the engineer should select whether the node is to use the global criteria (see Criteria-Diaphragm command), or whether the node should be connected or disconnected from the diaphragm.

When Connect Node to Diaphragm is chosen, the pull-down menu is activated and it shows all stories with respect to their associated diaphragm numbers. Once the story with diaphragm number is chosen from the menu, the user can connect any node to this diaphragm by Single, Fence or All command. Diaphragm connectivity information for all nodes can be checked in Frame Model Data report.

After the appropriate node connectivity is selected the engineer can assign this condition to a single node (click on Single), to multiple nodes (click on Fence) or to all nodes (click on All). If Single is selected the dialog will close and a target cursor will be made available. Click on each node to assign connectivity condition. If Fence is selected the dialog will close and a fence cursor will be made available. Click and drag a rectangle around all the nodes to assign connectivity conditions.

To hide the display of disconnected nodes automatically displayed for the assign operation un-select the View – Disconnected Nodes menu item.

It should be noted that there might be internal nodes along the boundaries of walls created during meshing walls. The following rules apply for the internal nodes:

if one of two top corner nodes of a wall is disconnected by the user, all the internal nodes along the top edge of the wall are disconnected by the program except the other corner node.
if one of two top corner nodes is connected by the user, all the internal nodes along the top edge of the wall are connected by the program except the other corner node.
If two top corner nodes are disconnected or connected by the user, all the internal nodes along the top edge are also disconnected or connected by the program.

Note that if diaphragm is a Semirigid diaphragm, this node connectivity assignment is not enforced (i.e., node connectivity\disconnectivity only works for rigid diaphragms).