Seismic Behavior of Moment‐Resisting Steel Frames: Experimental Study

An experimental evaluation of the seismic performance of moment‐resisting steel frames using weak‐column strong‐beam joints is described. This study is a continuation of an analytical investigation described in a companion paper. Five half‐scale specimens are tested using an inelastic substructure technique of the pseudodynamic test method. Most of the structural frame is analyzed using standard inelastic techniques while a critical component of the frame is tested. Results from this study suggest that weak‐column strong‐beam frames have sufficient ductility to sustain the inelastic demand induced by a major seismic event, but only if the base shear strength is larger than the minimum required by the Uniform Building Code. A frame tested with the minimum design base shear strength failed during the earthquake. Other characteristics, such as slenderness of the column cross section and axial load ratio, affect hysteretic behavior, but the overstrength of base shear capacity has the largest influence on the satisfactory performance of weak‐column strong‐beam frames.