EXPERIMENTAL AND ANALYTICAL STUDIES OF 3D FRAME STRUCTURE WITH BUCKLING RESTRAINED BRACING (BRB)

Buckling Restrained Bracings (BRB) are added in steel framed structure to resist primary lateral loads. The main feature of BRB is to increase stiffness and energy dissipation potential of the structure by providing excellent ductility. This concept is analyzed by three storey 3D steel frame prototype, with and without dampers. Dampers were prepared by using different infill material, such as Ground granulated blast furnace slag (GGBS) and Cement mortar. For this model two different BRB arrangements are adopted such as inverted V type and diagonal type. Model with BRB damper having infill of 70% GGBS with 30% Cement carried 6% additional load than 100% Cement in filled BRB damper. Dynamic analysis is conducted by subjecting the framed structure to a frequency of 150Hz and recording first three modal frequencies. Under this study diagonal dampers are more effective than inverted V type, because inverted V type arrangements causes buckling effect in beams. Diagonal bracings with 100% Cement mortar is 13% more effective in sustaining seismic loads than inverted V type.