Abstract: Steel bracing members are widely used in steel
structures to reduce lateral displacement and dissipate energy during
earthquake motions. Concentric steel bracing provide an excellent
approach for strengthening and stiffening steel buildings. Using these
braces the designer can hardly adjust the stiffness together with
ductility as needed because of buckling of braces in compression. In
this study the use of SMA bracing and steel bracing (Mega) utilized
in steel frames are investigated. The effectiveness of these two
systems in rehabilitating a mid-rise eight-storey steel frames were
examined using time-history nonlinear analysis utilizing seismostruct
software. Results show that both systems improve the strength and
stiffness of the original structure but due to excellent behavior of
SMA in nonlinear phase and under compressive forces this system
shows much better performance than the rehabilitation system of
Mega bracing.