By utilizing FEM analysis, based on monotonic tensile experiments and previous data, this study analyzed the behavior of beam-to-rectangular hollow section (RHS) column connections with exterior diaphragms. Unlike previous research, it suggests that the plastic region might not extend to the beam-end. Based on this, improved formulas are proposed in this paper for calculating the plastic and yield strengths of these connections, aiming to enhance accuracy in strength prediction and address recent discoveries in the mechanical behavior of connections. A comparison between Matsuo's traditional method and the new approach reveals that the latter offers superior accuracy and safety, providing lower estimates of yield strength and plastic strength, according to static analysis.
