Analysis of aseismic performance for dual system composed of steel frame and unbonded steel plate brace encased in reinforced concrete panel

The aseismic design for the dual system composed of the steel frame and the unbonded steel plate brace encased in reinforced concrete panel (Panel BRB) was studied to examine the effect of the lateral resistance of steel frames on the aseismic performance of the structures. The time-history analysis reveals that, generally, the inter-story deformation, the plastic deformation of members and the weight of floors carried by the chevron Panel BRBs decrease when the frames are reinforced. It is advantageous to the working behavior of the Panel BRBs, and the hysteretic curves of the left brace and the right one in a chevron Panel BRB are more symmetrical about the origin of coordinates. Whereas, the amount of steel used in structures and the story shear forces of the structures increase when frame members are enlarged, and a reduction in the extent of the plastic development for the frames is not remarkable when the maximum inter-story drift of structures is 1/50 according to the push-over analysis. Based on the results, it is advised that the aseismic design for the dual systems should be performed to ensure that the frame can independently resist 25 percent of the total base shear force of the structure.