Static Tests on T-Stiffener and Doubler Plate Reinforced Moment Connections with RHS Columns

Two beam-to-column connections for limited-ductility (Type LD) steel moment-resisting frames (MRFs) with rectangular hollow section (RHS) columns are investigated. The first connection is reinforced externally using T–T-stiffeners. The second contains top and bottom moment plates (designed for tension and compression) that are welded to a doubler plate reinforced RHS wall. This paper presents an initial comparison of the CSA S16:19 and AISC 341-16 design requirements for Type LD MRF and ordinary moment frame connections; rational design approaches for the two connections considered based on previous research; a summary of two large-scale, monotonic tests performed on the connections at Dalhousie University; and an evaluation of the strength, stiffness, and overall behaviour of each connection assembly.