Development and full-scale experimental evaluation of a novel replaceable fuses metallic damper with double-stage yield mechanism

Abstract

This study introduces a novel Replaceable Fuses Metallic Damper (RFMD) with a double-stage yield mechanism, aiming to enhance the energy dissipation capacity of structures across multiple seismic levels. The RFMD, designed with two steel pieces as the main body and a series of mild steel round bars as energy absorbers, is intended for installation along the bracing element. The external part of the RFMD must be fixed, while the internal part, with one degree of translational freedom, acts like a sliding piston along its longitudinal axis. During tension and compression in the brace, the movement of the internal part leads to bending and axial plastic deformations in the bars, absorbing energy and providing damping for the structure. Furthermore, shifts in the boundary conditions of the fuses during the loading procedure result in a two-stage yielding mechanism. The performance of a series of full-scale RFMDs was carefully examined through displacement-control monotonic and cyclic tests, demonstrating consistent stable hysteretic behavior and proper ductility over numerous cycles with no sudden decrease in stiffness or strength. The damper enables easy replacement of its fuses, which could prevent the necessity of post-earthquake replacements if engineered to avoid bar failure during intended movement. Serving as a simple, practical, and cost-effective passive energy dissipation device, the RFMD offers adequate ductility and energy dissipation, making it valuable for protecting the key components of structures.