Magneto rheological damper used in building structure The vibration of building structures is an important cause of a major disaster, on its vibration control is an important subject of study in today's world, magneto rheological damper is a kind of advanced actuators, the researchers for this Lord company developed the building structure anti vibration damper [9 ~ 11], shown in Figure 3, the maximum damping force is 20t, adjustable damping coefficient is 10, it will be the cylinder as a part of the magnetic circuit, between the outer cylinder and piston clearance as a damping channel, in order to increase the damping force by three piston are connected in series, the electromagnetic coil is wound on the piston, while the design of the compensation device specific, damper stroke was + 8cm, diameter 20.3cm, total length of about 100cm, the consumption of magnetic fluids 5L. Dongguan Jincheng Industrial Co., Ltd. is a research and development, manufacturing, sale of tension control, magnetic damper, as one of the professional manufacturers, the main production: tension device series, magnetic damper series, tension device, magnetic damper, magnetic damper damper, damper, and other goods. Www.www.swlawyer.org.cn Unlike the car seat suspension damper application environment, building structure vibration control damper for most of the time be stationary, which means that can not rely on the damper piston movement to sustain the MR fluid stability, rheological body must be long time maintain stability and coagulation settlement stability, viscosity of magnetorheological larger body to prevent magnetic particle settlement and condensed using zero magnetic field, sealing and wear is not the key issues to consider. DykeSJ [12] studied the application of magneto rheological damper, through simulation and laboratory model experiments show that: using acceleration feedback control policy about, can get ideal control effect, researchers are working on the development of magneto rheological damper is similar, for smart structures actuator model.