Experimental research on hysteretic behavior of dog-bone style beam-column connections

During the 1994 Northridge earthquake and 1995 Kobe earthquake, the typical beam-column moment connection (bolted-web-welded-flange) in steel moment-resisting frame suffered unexpected brittle failures. A kind of new connection types was put forward. This steel moment connections with reduced-beam sections are usually named as Dog-bone Style connections. So it is very necessary that studying the behavior of Dog-bone Style connections under cyclic reversal loading. In this paper two full-scale specimens of Dog-bone Style using H-section member had been conducted. The specimens were subjected to cyclic reversal loading simulating earthquake effects on a steel moment-resisting force. The objective of the work is to determine the behavior of these connections under cyclic reversal loading well into the inelastic range and to ascertain the effect of design parameters such as column flange stiffener, conditions of stress development,the distributing of stress on the overall behavior. Observations were made concerning the response of the connections and its elements in terms of strength, stiffness and energy dissipation. Information on the design of these connections is presented. The hysteretic behavior of Dog-bone Style beam-column connections under cyclic loading is presented in this paper. Results of the experiment show that the dog-bone style connections have better behavior of ductility and energy dissipation, and the rotations of all connections exceed 0.03 radians. The strength of weld seams and the weaken degree of beam flanges are those of the most important factors,which have crucial influence on the cyclic behavior of connections. It is suggested that by trimming the beam flanges according to the moment profile,the ductility of the connections can be improved and the ductile design on steel frame can be realized.