NEGATIVE STIFFNESS DEVICE AND METHOD

摘要

Negative stiffness systems and methods for seismic protection of a structure is described. A system can include a negative stiffness device having a first linkage pivotably connected to an anchor frame at a first pivot point and pivotably connected the movement frame at a second pivot point. The negative stiffness device can include a spring having a first end operably coupled to the anchor frame and a second end operably coupled to a movement frame. In a rest state, the spring can be compressed to exert a preload force to the first linkage and the anchor frame and not displace the first linkage and the movement frame. In an engaged state, the spring can be configured to apply a force to the first linkage such that the movement frame is displaced in a same lateral direction of a seismic load. The spring force can be amplified by the first linkage.

主权项

1. A negative stiffness system for seismic protection of a structure, comprising:
an anchor frame and a movement frame, the movement frame being laterally translatable relative to the anchor frame; a first negative stiffness device, including:
a first linkage pivotably connected to the anchor frame at a first pivot point and pivotably connected the movement frame at a second pivot point;a spring having a first end operably coupled to the anchor frame and a second end operably coupled to the movement frame, the compressed spring having a spring force;wherein in a rest state, the spring is compressed to exert a preload force to the first linkage and the anchor frame and not displace the first linkage and the movement frame;wherein in an engaged state, the spring is configured to apply a force to the first linkage such that the movement frame is displaced in a same lateral direction of a seismic load; andwherein the spring force is amplified by the first linkage when the frame is laterally displaced to an amplification point; and at least one additional negative stiffness device, each additional negative stiffness device including:
a second linkage pivotably connected to the anchor frame at a first pivot point and pivotably connected the movement frame at a second pivot point;a second spring having a first end operably coupled to the first linkage of the first negative stiffness device and a second end operably coupled to the second linkage, the spring having a second spring force;wherein in a rest state, the second spring is compressed to exert a preload force to the first linkage and the anchor frame and not displace the first linkage and the movement frame;wherein in an engaged state, the second spring is configured to apply a second force to the first linkage of the first negative stiffness device such that the movement frame is displaced in the same lateral direction of the seismic load; andwherein the second spring force is amplified by the first linkage when the frame is laterally displaced to the amplification point.