Disconnect Nodes
RAM Frame provides the engineer the ability to disconnect or connect nodes to a story diaphragm.
The end nodes of a beam located within a diaphragm slab edge are automatically considered connected to that diaphragm. Nodes along the length of the beam (from intersecting lateral braces, beams or supported columns) can be disconnected from the diaphragm if the Disconnect Internal Nodes of Beams option is selected in the Disconnect Nodes dialog (click Disconnect in the Story Diaphragm dialog).
Technical Notes
RAM Frame internally maintains a list of nodes which are required to perform the finite element analysis. The intersection of any two frame members is considered to be a node, as are the end points of all frame columns, beams, braces and walls.
Nodes considered connected to a diaphragm are constrained to move with the diaphragm. This will result in a faster analysis (due to the fewer degrees of freedom at each story level). Note that if all the nodes along a frame beam are connected to the diaphragm then no axial load will be generated in the beam. This is because the beam cannot shorten or elongate along its length due to its constraint to the infinitely stiff diaphragm.