Abstract
This work aims to establish the mathematical model with the high effectiveness in predicting the damping force of an MR damper with nonmagnetized passages in piston. The pressure drops due to viscous loss, MR effect, and the minor losses at the inlet and outlet of passages are considered in the mathematical model. The widely reported Bingham model is adopted to describe the mechanical property of MR fluid. The mechanical behaviours of the MR damper are experimentally evaluated under different excitations and current. The yield stress of MR fluid with respect to the current applied to piston coil is obtained by finite element analysis in Ansoft Maxwell 14.0. The proposed model is validated by comparing the simulated damping characteristics with the measured data under various currents applied to the piston coil. The simulated results are also compared with those obtained from the mathematical model without the pressure drop due to the minor losses at the inlet and outlet of passages. The comparisons show that the proposed mathematical model can yield more accurate predictions of damping force. This indicates that the pressure drop due to the minor losses is significant and nonnegligible. The nonlinearity of force-velocity characteristics is discussed. In order to quantitatively explain the necessity of taking the minor losses into account for modelling the MR damper, the proportion of pressure drop due to the minor losses to the total pressure drop is investigated and discussed. Pressure drops due to the minor losses and viscous loss are also investigated and discussed. At last, the proposed mathematical model is used to analyse the working principle of nonmagnetized passages.
Highlights
MR damper is the energy absorber with favorable performance based on the rheological property of MR fluid. e MR fluid is the smart material composed of micrometerscale magnetic particles and carrier oil
Both viscous loss and minor losses are adopted in the proposed mathematical model. e widely reported Bingham model is adopted to describe the property of MR fluid. e yield stress of MR fluid with respect to the current applied to piston coil is obtained by an empirical equation and by the finite element analysis in Ansoft Maxwell 14.0
–400 –600 –400 –200 0 200 400 600 Velocity VL minor losses (ML) and VL Experiment simulated and measured results are used to evaluate the performance of the mathematical model
Summary
MR damper is the energy absorber with favorable performance based on the rheological property of MR fluid. e MR fluid is the smart material composed of micrometerscale magnetic particles and carrier oil. Is MR damper, attributed to the nonmagnetized passages, results in a relatively much larger preyield-like region where the damping force gradually increases with piston velocity [14,15,16,17,18,19]. Is work aims to establish a mathematical model with high effectiveness for predicting the damping force of an MR damper with nonmagnetized passages in piston. Both viscous loss and minor losses are adopted in the proposed mathematical model. Test conditions are listed in Table 1. e test is carried out under sinusoidal periodic excitation. e maximum velocity is 0.52 m/s. e current is applied to the piston electromagnetic coil. e current will generate heat and increase the MR damper’s temperature. erefore, the temperature of the MR damper is monitored by a thermal sensor
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
