Performance-Based Design and Optimization of Buckling Restrained Knee Braced Truss Moment Frame

AbstractA buckling restrained knee braced truss moment frame (BRKBTMF) is a novel steel structural system that combines steel trusses with buckling-restrained braces (BRBs) to form an alternative seismic force–resisting system. The combination of the steel trusses and the BRBs allows the BRKBTMF to have a large interior opening without the need to provide ductile detailing for the steel trusses. This makes the design very efficient and economical. More importantly, through the use of BRBs as the designated energy-dissipation devices, the damage is controlled within the BRBs, which can be replaced easily after the earthquake. This will drastically reduce the structural damage, repair cost, and repair time, which makes this structure more efficient and resilient toward future earthquakes. In this study, a modification of the performance-based plastic design (PBPD) procedure was derived to design the member sizes of the BRKBTMF. A parameter study was conducted by varying the inclination of BRBs to optimize t...