Experimental study of a large-scale buckling-restrained braced frame using the pseudo-dynamic testing method

As part of an integrated analytical and experimental research program on buckling-restrained braced frames (BRBFs), a large-scale BRBF was tested using the pseudo-dynamic method. The test frame was subjected to multiple earthquake simulations using the explicit Newmark algorithm. A hybrid testing approach was implemented to account for the P-effects associated with the gravity load carried by the prototype building's gravity frames. The test frame sustained significant drift demands with almost no damage. Story drifts of nearly 5% and buckling-restrained brace maximum ductility demands of over 25 were observed in the maximum considered earthquake simulation. No stiffness or strength degradation was observed. Although residual drifts were large, the testing program demonstrated that the BRBF system can withstand significant seismic input and retain full lateral load-carrying capacity. Non-conventional brace-gusset and beam-column connections demonstrated excellent performance under very large drift demands.