Design and experiment of an innovative rotational two-level friction damper

Abstract

In this paper, a novel rotational two-level friction damper (RTFD) was proposed and its cyclic behavior was experimentally validated. The RTFD realizes the two-level working behavior through the gap mechanism between the rotary plates and the inner plates, which is optimized to mitigate the structural vibrations in various magnitudes of excitations. In particular, the RTFD amplifies the bearing force and deformation of the friction materials through the lever mechanism, achieving higher energy consumption efficiency. The working mechanism of the RTFD is discussed and the analytical design principles are presented to quantify the performance of the developed dampers. Moreover, a full-size prototype specimen was designed, manufactured, and tested with a repeated general loading scheme and cyclic loading scheme with a constant amplitude to investigate the seismic performance of the proposed damper. The experimental phenomena indicate the feasibility of the two-level working mechanism of the proposed RTFD and the ignorable wear of the friction subs. The experimental results confirm that the innovation damper is characterized by stable hysteresis behavior and favorable two-level energy dissipation capacity. Moreover, the remarkable recoverability of the developed RTFD is demonstrated by the narrow variation of 10.51% in the bearing force and 7.93% in the accumulative dissipated energy between repeated loadings.