EXPERIMENTAL STUDY ON MECHANICAL PERFORMANCE OF DISPLACEMENT-AMPLIFIED ROTATIONAL FRICTION DAMPER

The energy dissipation performance of a friction damper is directly related to the displacement and the friction contact area. A novel displacement-amplified rotating friction damper with multiple friction surfaces and nodal displacement amplification effects is presented. The computational theoretical model is introduced, and six sets of specimens are designed with two levels of bolt preloading force and three types of new composite friction materials (copper fiber, steel fiber, ceramic fiber) as control parameters. Low cyclic loading tests are conducted, and the hysteresis curves of each specimen are obtained. A comparative analysis of the fatigue performance of the three types of new composite materials is carried out. Additionally, parameter analysis is performed using ABAQUS software. The theoretical calculation results are compared with the experimental results. The results show that all specimens exhibit full hysteresis loops, presenting a parallelogram shape with sliding phenomenon during the unloading phase. The copper fiber composite material and ceramic fiber composite material demonstrate good fatigue performance, while the steel fiber composite material exhibits poor fatigue performance with the worst friction plate wear. Incorporating dampers during node reinforcement does not significantly impact the initial stiffness, while effectively enhancing the stiffness of nodes under damaged conditions. Reducing the length of the intermediate connecting rod in the damper can effectively improve the displacement amplification capability and enhance the energy dissipation capacity to some extent. A decrease of 200 mm in rod length increases the maximum damping force by 5.5 times and amplifies the node rotation angle by 3.92 times. The relative errors of experiments, finite element simulations and theoretical calculations are all within 10%. This research outcome can serve as a reference for related studies on friction dampers.