Experimental Response of Damage-Free Self-Centering Links for Seismic Resilient Eccentrically Braced Frames

In the last few decades, numerous damage-free self-centering solutions have been proposed to achieve seismic resilience of steel structures. While most research studies have focused on moment resisting frames and concentrically braced frames, relatively few works have explored seismic-resilient solutions for eccentrically braced frames (EBF). The present study addresses this gap by investigating a damage-free self-centering device to be employed as seismic link in EBF. The device combines longitudinal posttensioned bars with disk springs to control the self-centering behavior and friction devices to provide seismic energy dissipation capacity. This paper presents the findings of an experimental campaign conducted at the StrEngTH Laboratory of the University of Salerno, Italy, aimed at characterizing the cyclic behavior of the proposed self-centering link. The tests were performed according to the ANSI/AISC 341 cyclic load protocol. Additionally, a 3D finite element model was developed in ABAQUS and validated against test results to further analyze the device's performance. The experimental test results and numerical simulations revealed the proposed device's advantages, allowing also the validation of proper analytical design equations.