Assessment of the seismic behavior of different braced systems for mid rise steel buildings

This study aimed to compare the seismic behavior of different bracing systems with different angles of bracing geometry for mid-rise 2D steel buildings of 2, 4, 6, and 8 stories. Nonlinear static pushover analyses carried out to assess the structural seismic performance. Eight structural configurations investigated moment resisting frames, Chevron braced frames, multi Chevron braced frames, V-braced frames, multi V-braced frames, X-braced frames, multi X-braced frames, and diagonal braced frames. Seven angles used: 30, 45, 60, 75, 90, 105 and 120 for each type of bracing system. The effects of some parameters influencing the seismic performance, including type of the bracing system, different angles of bracing geometry and the height of the building investigated. The results show that the different braced frames with different angles of bracing geometry performed well in terms of story displacement, base shear and performance point when compared with the moment resisting frame in mid-high rise steel buildings. It can be concluded, on a comparative account of the obtained results enhances structural performances. In term of base shear and roof displacement, the seismic response, diagonal braced frames and X-braced frames have better seismic response. The bracing angles between 45 and 90 degrees generally give good performance. Keywords: Nonlinear pushover analysis, Base shear and displacement, Seismic performance, steel structure building, Bracing systems.