Self-centering cable brace with friction devices for enhancing seismic performance of RC frame structures

Abstract A novel self-centering cable brace (SCCB) with friction devices is developed to improve the seismic performance of existing RC frame structures. This paper presents the structural configuration and the theoretical load-displacement relationship of the SCCB. Cyclic loading tests are conducted to show the effectiveness of the SCCB, and a numerical model is established and validated based on the test results. A parametric analysis is made to investigate the influence of tendon stiffness and friction on hysteretic performance of the SCCB. Nonlinear dynamic analyses are further carried out on a nine-story RC frame, which is seismically deficient and enhanced with buckling restrained braces (BRBs) and SCCBs respectively for comparison. Inter-story and residual inter-story drifts, base shear forces, load-axial elongation relationships and self-centering indexes of the bare and strengthened frames are obtained and compared. It is found that both the SCCBs and BRBs increase the seismic capacity, while the SCCBs can reduce the maximum story drifts more significantly and have much less residual story drifts than BRBs.