Replaceable Displacement-Amplifying Rotary Friction Damper: Experimental and Numerical Investigation

Abstract

Timber structures are vulnerable to failure and collapse under seismic action. To improve the seismic performance of such structures, a replaceable displacement amplification rotary friction damper was proposed and designed. Six specimens were fabricated, each varying in pretension strains and employing three different composite friction materials as control parameters, followed by low cyclic loading tests. The study investigated the working mechanism, hysteresis performance, energy dissipation capacity, performance stability, and displacement amplification effect of the dampers. A finite element model was developed to analyze the hysteresis performance of the damper and evaluate the impact of various parameters on its overall effectiveness. Furthermore, a comparative analysis of the damper’s hysteresis characteristics was conducted. The theoretical calculations and finite element analysis were validated using experimental results, showing a relative error within 10%. The specimens demonstrated a notable displacement amplification capability, which increased as the intermediate connector length decreased. By reducing the length by 200 mm, the maximum damping force could be amplified by 5.5 times, while the nodal rotation values increased by 3.92 times. Additionally, for every 50 με increment in pretension strain, energy consumption increases by an average of 148%, and for each unit increase in the friction coefficient, energy consumption increases by an average of 172%.