초록 ▼

A semi-active variable stiffness control (SAIVS) device, which can change its stiffness continuously and smoothly between a maximum and minimum stiffness. It comprises four spring and telescoping tube elements arranged in a rhombus configuration with pivot joints at the vertices. A control rod power

A semi-active variable stiffness control (SAIVS) device, which can change its stiffness continuously and smoothly between a maximum and minimum stiffness. It comprises four spring and telescoping tube elements arranged in a rhombus configuration with pivot joints at the vertices. A control rod powered by a DC servomotor reconfigures the aspect ratio of the rhombus under computer control. This aspect ratio determines the stiffness of the device, and is continuously variable using little power. The SAIVS is installed as a connection between structural elements, and varies the connection stiffness smoothly by changing its configuration in response to a control algorithm in the computer. The algorithm obtains accelerometer and displacement input as feedback to optimize the result. Thus it maintains the structure in a non-resonant vibration state under dynamic disturbances such as earthquakes and windstorms.

대표청구항 ▼

[ I claim:] [1.] A vibration damper connecting structural members and controlling the stiffness of the connection, comprising:four stiffness and damping elements pivotally connected end-to-end to form a quadrilateral with four linearly extendable sides and four pivotally flexible apexes, the quadril

[ I claim:] [1.] A vibration damper connecting structural members and controlling the stiffness of the connection, comprising:four stiffness and damping elements pivotally connected end-to-end to form a quadrilateral with four linearly extendable sides and four pivotally flexible apexes, the quadrilateral having first and second diagonals, each diagonal being a line between two opposite apexes of the quadrilateral and having first and second ends;a control rod connected to the quadrilateral apex located at the first end of the first diagonal;a first structural member;a bearing on the first structural member that constrains the control rod to linear movement in substantial alignment with the first diagonal;a carriage connected to the quadrilateral apex at the second end of the first diagonal;a second structural member;a rail attached to the second structural member parallel to the first diagonal;the carriage mounted and retained on the rail for movement parallel to the first diagonal;a fixed rod passing through the quadrilateral apex at each end of the second diagonal and attached to the first structural member;a sleeve on the quadrilateral apex at each end of the second diagonal, each sleeve mounted and retained on the fixed rod for slidable movement thereon;whereby linear movement of the control rod in the bearing changes the shape of the quadrilateral, thereby changing the stiffness of the connection between the first and second structural members.