Effects of Winding Cylinder Materials on Dynamic Performances of a New MR Damper

In the semi-active control system based on magnetorheological (MR) damper, the separating arrangement of displacement sensor and MR damper is easy to reduce the reliability and increase system cost. Moreover, the detection accuracy of the sensor is not high due to the external disturbance. Based on this, a new displacement differential self-sensing magnetorheological damper (NDDSMRD) is developed to over these shortcomings. The structure design and working principle of NDDSMRD are expounded. In order to analyze the influence of winding cylinder materials for the developed MR damper on displacement self-sensing and damping characteristics, magnetic field simulations and experiments are conducted to investigate the relationship between the damping magnetic flux and self-sensing magnetic flux densities with two winding cylinders made from different materials. A finite element model was built with ANSYS software and magnetic field simulations in static and harmonic state were presented, respectively. Simulation results show that the damping magnetic flux density generated for winding cylinder made of No.10 steel material surpasses the one made of stainless steel material, and the self-sensing voltages are proportional to the damper displacement though the winding cylinders are different. A dynamic experimental test rig was built up to analyze the dynamic damping performances and self-sensing ability. Experimental results show that the damping force produced by NDDSMRD with No.10 steel winding cylinder is larger than that with stainless steel winding cylinder. The self-sensing voltages are also linear to the damper displacements even though with the different winding cylinders. In addition, the self-sensing voltage generated by the stainless steel prototype is greater than the No.10 steel. Moreover, the self-sensing sensitivity of stainless steel winding cylinder can reach to 59mV/mm, which is 7.4 times greater than that the 8mV/mm for No.10 steel winding cylinder.