Cyclic behavior of honeycomb replaceable shear links in eccentrically braced steel frames: An experimental and analytical study

Replaceable shear links in eccentrically braced frames (EBFs) are designed to dissipate seismic energy through stable and highly ductile plastic deformation, thereby confining damage to easily replaceable components. However, conventional perforated shear links often suffer from premature localized cracking and rapid strength degradation due to instability, which significantly restricts their plastic rotation capacity and post-earthquake replaceability. To address these shortcomings, this study proposes a honeycomb-shaped replaceable shear link fabricated from LYP160 low-yield-point steel. The honeycomb topology aims to redistribute plastic demands, activate multi-ligament deformation, and delay the onset of crack localization. Four specimens were tested under cyclic loading to investigate the influences of steel grade (Q235 versus LYP160) and honeycomb opening configuration (single-row versus double-row). The test results demonstrate that the honeycomb arrangement fundamentally alters the shear transfer mechanism by triggering coupled deformation modes, including shear yielding, Vierendeel bending, and torsional plasticity in the ligaments. Compared with Q235 specimens, the LYP160 links developed more stable and widely distributed torsional yielding, effectively postponing crack coalescence and instability-induced failure. Among all specimens, the LYP160 single-row link exhibited the most favorable hysteretic behavior, achieving a ductility coefficient of 12.54 and a maximum plastic rotation of 0.17 rad. Although the double-row configuration enlarged the plastic deformation zone, its higher opening ratio compromised ligament stability. In addition, a mechanics-based analytical model was developed that accounts for shear-flow redistribution, ligament torsion, and stiffness reduction due to openings. The proposed model predicted the initial stiffness and yield strength with maximum absolute errors of 6.46% and 7.8%, respectively. Overall, the findings highlight the synergistic benefits of combining honeycomb topology with LYP160 steel and demonstrate its potential for developing damage-controllable shear links intended for post-earthquake replacement in steel EBF systems.