Cyclic shear response of non-seismic reinforced concrete frame strengthened with buckling-restrained X-shaped steel panel damper

In this study, the strengthening effect of a buckling-restrained X-shaped steel panel damper (BRPD) with cover plates on the shear response of a non-seismic reinforced concrete (RC) frame is verified. A non-strengthened RC frame and three RC frames strengthened with a BRPD were tested under constant axial and cyclic lateral loads. The main parameters were the connection method between the RC frame and the H-shaped frame connected to the BRPD, including in- and side-plane strengthening. Test results showed that in-plane strengthening using the BRPD effectively reduced the pinching effect, as indicated by a wide hysteresis loop in each cycle of the lateral load–displacement relationship. Consequently, the shear capacity, cumulative dissipated energy at the 80% of peak load in the post-peak behavior, and equivalent damping ratio of the in-plane strengthened RC frames using the H-shaped frame connected to the BRPD were 1.72, 5.15, and 2.18 times higher, respectively, than those of the non-strengthened RC frame.