Experimental and numerical study on hysteresis behaviour of a novel dual-stage friction damper

This study proposes a dual-stage friction damper (DSFD) based on traditional friction dampers, consisting of two series of traditional friction dampers. Consequently, it has two sliding friction forces: a small and a large sliding friction force, unlike the single sliding friction force in traditional friction dampers. This paper first introduces the basic structure and working mechanism of the damper and examines its hysteresis behavior, focusing on its design details. Performance tests were conducted on two friction dampers with different preloads to determine the friction coefficients. Subsequently, cyclic loading tests were performed on the DSFD. The test results showed that the deformation of the proposed DSFD aligned with the anticipated outcomes, with the hysteresis curves exhibiting dual-stage characteristics. The damper displayed an outstanding capacity for energy dissipation. During testing, the preload force on the bolts and the damper ' s energy dissipation ability were examined. Furthermore, the damper ' s reliability under cyclic loading was evaluated, revealing consistent performance across multiple load cycles. This indicates that the damper can be reused after multiple earthquakes. Moreover, a refined finite element model of the DSFD was developed. The numerical simulation results were in good agreement with the experimental results regarding the hysteresis curves and energy dissipation capacity of the DSFD. The discussion on the optimized design demonstrates the protective role of the sliding plate on the bolts. Finally, a parameter analysis was conducted to examine the influence of change parameters on the damper ' s performance.