Every so often the question comes up as to whether RAM Connection takes into account transfer forces. But what does this really mean?
AISC Design Guide 29 Vertical Bracing Connections—Analysis and Design Appendix D defines a transfer force in a connection as;
A force that must be transferred from one element to another through connection elements and whose magnitude and direction cannot be ascertained from the maximum member end forces.
An example of this definition can be shown in the following figure;
In this figure the connection connecting Braces 23 and 41 at node 15 must be able to adequately transfer the horizontal component of the force from the right to the left.
If the connection at node 15 looked like this;
Then one could use the column to transfer the load from the right side to the left. However if the connection looked like this;
Then one would need to take into account the transfer force when designing the gusset connection. Currently RAM Connection will design the right Column-Beam-Brace (CBB) connection for Column 18, Beam 37, and Brace 41 individually from the left Column-Beam-Brace (CBB) connection for Column 17, Beam 20, and Brace 23; and the program DOES NOT check that the gusset can adequately transfer the load from one side to the other. This condition however rarely happens since most bracing configurations that we typically see use the columns to transfer the load or look more like this;