Design and experiment of a new structure of MR damper for improving and self-monitoring the sedimentation stability of MR fluid

Abstract

Magnetorheological (MR) fluid damper is a high quality semi-active vibration damping device based on magnetorheological effect. However, one of the key factors restricting its development and application is the sedimentation of magnetic particles in MR fluids at present, which affects the working stability and service life of the damper, while there is a lack of effective method for monitoring sedimentation state of MR fluid inside the device in real time. A new structure of MR fluid damper for improving and monitoring the sedimentation stability of MR fluid is developed in this study based on the sedimentation principle and work characteristics of MR damper. Firstly, the theoretical analysis of the new MR fluid damper is carried out, then the prototype is designed and processed, the appropriate MR fluid is selected, finally the performance of the prototype is tested. The results of experiment show that the force of the new damper can be adjusted in both directions, and the output force can meet the requirements of working conditions. The resistance of MR fluid decreases and the conductivity of MR fluid increases in the middle of the damping channel, and the partial voltage at both ends of the non-inductive resistance increases gradually, which verifies the feasibility of the monitoring device for sedimentation. The voltage at both ends of the non-inductive resistance decreases slightly after placement for 24 weeks, so it can be judged that the sedimentation of MR fluid is weak in the new MR damper, which verifies the effectiveness of the new structure for improving sedimentation stability.

A Review on Structural Configurations of Magnetorheological Fluid Based Devices Reported in 2018–2020

“…In 2020, aiming to reduce the sedimentation of MRF, a damper shown in Figure 9A was designed (Huang et al, 2020). In this device, a permanent magnet is embedded in the piston to drive particles back and forth, and a conductive strip is disposed to monitor particle chains of MRF for a sedimentation amount.…”

“…In 2018, a prosthetic knee with a novel MRF brake was proposed, assisting humans to realize normal gait movement (Mousavi and Sayyaadi, 2018). The MRF brake, FIGURE 9 | (A) MRF damper with self-monitoring (Huang et al, 2020). (B) MRF damper with squeeze-valve mode (Ruan et al, 2020).…”

Design and experiment study of a novel dual-channel independent-coil magnetorheological grease damper

“…The calculation formula for magnetoresistance R mk is as follows [36]: The magnetoresistance R m1 and R m5 on both sides of the piston are obtained as follows,…”

Self-adapting model for variable stiffness magnetorheological dampers

“…With the rapid advance in vibration control technologies, magnetorheological fluid (MRF) dampers have become intelligent and ubiquitous in practical applications [1,2]. The structures and characteristics of MRF dampers are different according to the different conditions [3,4]. The variable stiffness MRF dampers improve the performance of vibration reduction due to its specialty of variable stiffness and damping, which is different with traditional MRF dampers [5].…”