Overstrength and plastic rotation of variable cross-section replaceable link

Abstract

This paper presents a comprehensive investigation of variable cross-section replaceable links (VRLs) through a combination of experimental and numerical analyses. Two types of specimens were designed: one with circular holes in the web plate (C-VRL) and the other with long holes in the web plate (LC-VRL). The performance of VRL specimens with circular and long holes in the web plate were analyzed, focusing on hysteresis curves, energy dissipation capacity, overstrength coefficient, and failure modes. The results showed that the C-VRL specimen exhibited stable and complete hysteresis loops with substantial plastic development and efficient energy dissipation. On the other hand, the LC-VRL specimen experienced reduced bearing capacity due to tearing around the long holes and sliding of the connection between the web plate and the flange. The C-VRL specimen demonstrated higher bearing capacity compared to the LC-VRL specimen, and both specimens exhibited favorable structural ductility. The numerical analysis involved a validated finite element model, considering various parameters such as the length and height of the energy-dissipation region, variable cross-section slope, and weakening form of the web plate. The energy dissipation capacity increased with the rotation angle for all specimens. The overstrength coefficient of the VRLs exceeded the recommended value, indicating its better load-carrying capacity. Overall, the study findings provide insights into the seismic performance, overstrength coefficient, and design considerations of VRLs in practical engineering applications.