Quasi-static tests and parametric simulations of hybrid steel frame and light wood shear walls with factional dampers

摘要

A slip-frictional damper connection with a lock-up system between walls and frames in hybrid steel frame and light wood shear wall systems is proposed to protect the main structural components from damage under earthquakes and expedite the post-earthquake recovery process. This paper presents quasi-static tests on six single-story-single-span planar specimens divided into two groups corresponding to 1.65 m and 2.2 m in height, respectively. The lateral behavior for the overall system and the subassemblies, i.e. the frame, the wall, and the damper, corresponding to different damper configurations were compared. Numerical models considering the nonlinear behavior of the sheathing-to-framing connections and the dampers were created with OpenSees to conduct parametric studies to further understand the influence of the wall-to-frame stiffness ratio. The results suggest that the slip-frictional dampers strongly increase the energy dissipation ability and the hysteretic damping, and reduce the damage in the main structural components, especially the shear wall. To maximize these benefits, a total activation load of the dampers around 40% of the capacity of the connected wall is recommended, along with dampers reaching the end of their stroke at a drift corresponding to the yielding of the steel frame. The wall-to-frame stiffness ratio also affects the lateral behavior. Structures with larger stiffness ratios exhibit enhanced energy dissipation capability and larger damage-free inter-story drift. The damped structure remains damage-free up to about 1.5% inter-story drift when the wall-to-frame stiffness ratio is 6:1.