Research and Development of Magnetorheological Spiral-flow Damper

Magnetorheological fluid, or MR fluid, can be transformed from low viscosity Newtonian fluid to Bingham fluid with higher viscosity and shear stress within only microseconds by applying external magnetic field. Thus, the damping characteristic of Magneto-Rheological fluid dampers, or MRF dampers, can be easily regulated to effectively absorb the impact or vibration energy. A semi-active magneto-rheological spiral-flow (MR-SF) damper has been developed by integrating the passive and active (damping principles) through the spiral MR fluid channel. The channel structure of damper can be easily varied by replacing the channel part with different spiral-pitches. The proposed modularization design is available for not only the commercial dampers but other hydraulic cylinders, which saves time for maintenance. The operating performance of developed MR-SF damper was tested and measured by using the MTS_810 tensioning equipment. The passive damping force is 149 N at the operating speed of 6.28 mm/s without magnetic field, and the active damping force reaches its maximum value as 521 N when driving current is 2.0 A. The damping force also comes to stagnate since the MR fluid becomes magnetically saturated with higher driving current. Its dynamic ratio is 3.49. Therefore, damping force can be easily regulated by the modulating driving current. For realizing the close-loop control algorithm, the damping hysteresis behavior of the MR-SF damper is modeled based on the Bouc-Wen hysteresis model with MATLAB and Simulink. Furthermore by using the artificial neural network (ANN) algorithm, the damping coefficient is controlled by regulating magnetic field. Through the developed close-loop control algorithm, the MR-SF damper model can effectively reduce 41.6% of stimulated vibration. Through the novel concept of the spiral-flow channel, the developed MR-SF damper can realize a wide range of dynamic ratio. The passive damping function provides the main damping effect by the viscous drag, and the active damping function delivers the adjustable damping effect.