Development of Autonomous Negative Stiffness Damper for Reducing Absolute Responses

In this paper, a new vibration control device realizing negative stiffness in a passive manner is proposed in order to reduce the absolute response of structures under strong seismic motions. The developed device consists of a sliding plate with a PTFE portion, and they are vertically pressurized by coil springs. The shape of the sliding plate is convex, by which the control force is negatively proportional to the deformation. The prototype of the proposed device was assembled, and its performance was investigated through both sinusoidal and hybrid loading tests. It was confirmed that the proposed device reduced the maximum acceleration of the structure significantly without any significant increase in absolute displacement.