Numerical study of concentrically braced frames with the replaceable reduced section under cyclic loading

Concentrically braced frames are common systems used for lateral loads of structures. These systems have low displacement and high stiffness. Therefore, many studies have been done to improve the behavior of these systems in recent years. Some research has aimed to increase the ductility and energy absorption of the concentrically braced frames. Since bucking of these systems in compression prevents using their maximum capacity, this research aims to improve the cyclic behavior, ductility, and energy absorption of the mentioned systems using the reduced section. In this paper, the reduced section has been created by installing a smaller profile, compared to the main brace, to act as an energy dissipation element for the bracing system and make the reduced section replaceable. The reduced section yields before the main brace buckles. As a result, the main concentrically braced frame prevented from buckling. In this paper, three finite element models have been analyzed numerically. Then, the reduced section (fuse) was reinforced to improve the strength and stability of the fuse and brace system. The results showed that in the proposed models, ductility increased by 57% and 59% in tension and compression, respectively, energy absorption increased by 14%, and a stable hysteresis curve was illustrated. Using the reduced section has increased ductility, energy absorption, and hysteresis behavior in the brace system. Moreover, reinforcing the reduced section has improved the cyclic behavior and strength of the bracing system significantly, and a stable hysteresis behavior was observed. © 2023, The Author(s), under exclusive licence to Springer Nature Switzerland AG.