Seismic Performance Of Bolted Endplate Steel Coupling Beams For Coupled Composite Shear Wall

Due to the emergence of a large number of high-rise and super high-rise complicated building, traditional reinforced concrete coupled shear wall structure system is difficult to meet the requirement of structure. This makes the structural materials gradually develop towards composite and a large number of steel- concrete composite structure systems show up. In order to adapt to the increasing composite steel-concrete coupled shear wall,the bolted-endplate connections widely used in steel structures with its advantages of structural simplicity, easily operation and good seismic behavior is introduced into the steel-concrete hybrid coupled shear wall structures. Firstly, the internal force of the shear wall was obtained through the design of prototype structure to analyze the feasibility of bolted-endplate connections in hybrid coupled shear walls of the high-rise buildings. Furthermore, six specimens of 1/2 scaled steel coupling beams were tested under low cycle reversed loading.The cross section of the six steel coupling beam specimens were identical. Based on the length of clear span, three specimens were shear dominant, two specimens were flexure dominant, and the last one was flexure and shear dominant. As for shear dominant specimens, two of them were connected by bolted-endplates connections while the other one was connected by ordinary connection. Bolted-endplate-connection specimens were different in the connection details. Reduced beam section(RBS) was introduced to one of the flexure dominant specimens.The experiments investigate the steel coupling beams’ influence on reinforced concrete wall, the hysteretic behavior of the steel coupling beams, the degradations of rigidity, the ductility and failure patterns of specimens, the energy dissipation capacity and the strain relationship. The experimental results indicate that no matter what form of deformation, the required nonlinear displacement, diversion and good seismic behavior of the steel coupling beams will be achieved with reasonable design and supervise quality of construction. Furthermore, because of the difference in stress conditions, the undesired failure patterns occurred in experiments indicated that bolted-endplate design methods in steel structures directly introduced into the design of the steel-concrete hybrid coupled shear wall structures is not suitable. Thus this paper suggests an increasing of 10~20% in the calculation of the thickness of the endplate.