Experimental optimization studies on steel core lengths in buckling restrained braces

Concentric braced frames are commonly used in steel structures to withstand lateral forces. However, brace hysteretic behavior is asymmetric in tension and compression. These frames typically exhibit substantial strength deterioration when loaded in compression. Consequently, the concept of Buckling Restrained Brace (BRB) has been introduced to overcome this deficiency.The length of a BRB steel core could have a significant effect on its overall behavior since it directly influences the energy dissipation of the member. Furthermore, BRB could be effectively utilized as a damper to dissipate seismic input energy, particularly when used as a fuse within the brace in a frame. Modified BRBs with shorter lengths may be called damper BRBs, because they function as if a typical damper is utilized along any brace member. These damper BRBs are fabricated and tested in this study both experimentally and analytically. Useful insights into local retrofitting of core plates and connections are also provided.

► Experimental and analytical studies are carried out to attain insights into optimized steel core length for damper BRBs.
► Small specimens are constructed and installed easily within diagonal members while the other part of the brace showing no yielding and failure for service and seismic loading.
► A formula is proposed for optimized steel core length for damper BRBs.