Development of a Displacement-Based Design Method for Steel Dual Systems With Buckling-Restrained Braces and Moment-Resisting Frames

Dual systems can offer an attractive lateral force-resisting solution, combining individual systems in a complementary manner. A displacement based-design (DBD) method is proposed for steel dual systems incorporating moment-resisting frames (MRFs) and buckling-restrained braces (BRBs). The validity of the method is established through a verification study considering theoretical designs of 6-, 9-, 12-, and 18-story buildings and nonlinear time-history analysis (NTHA) using ten spectrum compatible accelerograms. The results show that the DBD method provides good control of displacements and drifts for the structures, although higher mode effects tend to become significant for the taller case studies. In addition to controlling peak deformations, the article illustrates how the inclusion of the MRFs in parallel to BRB systems can be an effective means of limiting residual deformations.