Optimization of Buckling Restrained Braced Frame Under Seismic Loading

Abstract eng:
This study proposes a design procedure for the optimization of buckling restrained braced frames (BRBF) subjected to seismic loading. The stiffness distribution of the buckling restrained braces (BRBs) is optimized at the system-level. The parameters of a BRB component can be obtained according to the optimized stiffness. The seismic excitation is represented as a zero-mean filtered white noise and is formulated in the augmented state space with the BRBF structure. The hysteretic behavior of the BRB components are represented by the Bouc-Wen model and linearized to fit the state space formulation. The optimization objective is defined in terms of stationary structural responses. In the illustrative example, ductility and interstory drift are considered as the optimization objectives. The optimized results are compared with the common design practice according to the equivalent lateral force (ELF) procedure as specified by ASCE-7. The optimal BRBF design with minimized interstory drift response is similar to the design obtained by the ELF procedure, which, however, usually results in soft stories and nonuniform energy dissipation along the height. To uniformly distribute and minimize the ductility demand of the BRBF, the optimized design tends to distribute the stiffness inversely proportional with height and more stiffness is distributed at the first floor.

• Export as: BibTeX | MARC | MARCXML | DC | EndNote | NLM | RefWorks
• Add to your basket