Damper Design In Column And Research Of Vibration Control

There are two kinds of vibration of column with the wind, one is along the wind,another is cross the wind. The column will happen to resonance when the vibrationfrequency is equivalent to natural frequency of vibration of tower. To reduce thedamage of the sympathetic vibration, it can be used to control the amplitude at the topof column with dampers. In this paper, damper is studied in the column vibrationcontrol to design suitable damper for column.A non-damped dynamic vibration absorber is used to be basic principle model inthis paper. A ball damper and a spring damper are designed with the principle. Theball damper consists of four quality pendulums, which are arranged around the towerbody in90°each other. The spring damper’s mass is designed for annular, mass andthe tower body are connected by a spring, a support plate is under the mass. The massratio is definited from1/50to1/10according to the principle of dynamic vibrationabsorber and the application in tall structures.In view of the design of the ball damper and spring damper, a small scaleexperimental model is established, and a vibration test experiment is carried out.Results show that the improvement of system damping ratio of two kinds of dampersincrease with the mass ratio and the ascension of the installation location, and springdamper vibration control effect is better than that of the ball damper. For ball dampers,when the damper is installed under2/3height of column, or installed in1/2height ofcolumn and mass ratio is bigger than1/30, the damper can play a well vibrationcontrol effect. For a spring damper, when the damper is installed under2/3height ofcolumn, or installed in1/2height and mass ratio is1/10, the damper can play a goodvibration control effect.In order to further analysis of the vibration control effect of damper, thenumerical simulation models are established by two kinds of damper, for which thetransient dynamic analysis and harmony response analysis could be calculate in thispaper. Results show that when the installation position is higher than2/3height, bothtypes of dampers can play a good vibration control effect. When the total mass ratio isnot changed, the damper’s number does not affect the effect of vibration insulation. As the improved structure oftwo kinds of damper, multi frequency damper can reducenot only the amplitude of the first vibration mode effectively, but also can avoid thelarger second modal amplitude.The research in this paper provide foundations for the design of damper incolumn.