A friction damper with displacement dependent variable damping force characteristics was developed. The damper was designed to decrease damping force when damper displacement exceeded a predetermined value. Therefore, the damper is ideal for aseismic retrofit of existing skyscraper buildings in preparation for long-period earthquake ground motions expected to occur in the near future. Dynamic loading tests were conducted on a full-scale steel frame with a brace-type variable friction damper to verify the damper performance. The damper exhibited on-target characteristics, stable performance, and a high endurance capacity under cyclic loadings.
