Development and performance research of an Xadas damper with a double-phased yield mechanism

Abstract

In this paper, an X-shaped added damping and stiffness damper with a double-phased yield mechanism (Xadas-DY) is proposed, which consists of bending plates with different yield strengths and two connection plates. The combination of steel plates with different yield strengths endows the damper to provide sufficient energy dissipation and proper stiffness for the primary structures. Design method of Xadas-DY, including the elastic stiffness, the yield strength, the yield displacement, the monotonic load–displacement relationship considering the membrane effect are proposed. Coordinated design methods for the load capacity, stiffness and yield displacement between Xadas-DY and the anticipated application primary structure are summarized. Sixteen specimens are designed for testing under monotonic and cyclic loading test to investigate their double-phased workability. The test results reveal that the Xadas-DY specimens demonstrate satisfactory plastic development with full hysteretic curves, stable capacity and favorable energy dissipation ability. The overstrength behavior and the influencing factors are also analyzed. Meanwhile, the impact of design parameters such as the height (H), width (B) and thickness (t) of X-shaped bending plates is analyzed and summarized to provide a more comprehensive reference. Moreover, a detailed numerical model considering the membrane effect is established and validated. The numerical result agreed well with the test result in terms of the cyclic response, stiffness, key displacements and loads of Xadas-DY. Besides, the double-staged working mechanism and the influence of shape of the bending plates are also clearly unveiled through numerical analysis.