Magnetorheological (MR) dampers are smart devices characterized as high damping force, short response time and
lower energy consumption. They provide a promising way for vehicle isolation. However, transmissibility of
conventional MR damper increases significantly at high frequency because of stiffness hardening. For this reason, new
MR damper with decoupling mechanism has been designed. The design is sensitive to amplitude and frequency of
vibration, and produces stiffness and damping varied with amplitudes and frequencies vibrations. Dynamic model is
derived based on Bingham model. Mathematical expressions of dynamic characteristics, including dynamic stiffness,
delay angle, force transmission rate and dynamic range of damping force, are deducted by solving the models.
Numerical simulations are used to study the dynamic characteristics. The results indicate that, the design produces large
damping force in the low frequency high amplitude case and small damping force low stiffness in the opposite case. The
high frequency stiffness hardening is avoided. This MR damper can be used to semi-active vibration control of vehicles.