Rationale Behind and Proper Application of the Ductility Factor for Bracing Connections

Referenced in Chapter 13 of the AISC LRFD Manual, 3rd Edition is a somewhat elusive stress factor for bracing connections based on research by Dr. Ralph M. Richard at the University of Arizona. The stress factor, commonly referred to as the "Richard Factor"ť, was incorporated into bracing connection design philosophy in the Uniform Force Method to ensure ductility in the connection. The history and relevance of this ductility factor is clarified in this paper, with particular attention given to its function in the current recommendations of the manual.