Theoretic and experimental study of chain-formation mechanism for MRF

Comprehensive theoretical and experimental analyses of chain-formation process for magnetorheological fluid(MRF) are performed in this paper.Firstly,the physical model for the chain-formation process has been established.The Monte Carlo method has been used to simulate the chain-formation process under the gradient magnetic field.Secondly,we study the chain-formation process of MRF under the magnetic field by experiment.Numerical and experimental studies show that: when the magnetic field direction is parallel to the level of magnetorheological fluid and the external magnetic field is zero,magnetic particles are disordered.when the magnetic field strength increases gradually,the magnetic particles form smaller chains,mesh and even columnar structure along the direction of magnetic field;When there is a certain angle between the magnetic field direction and magnetorheological fluid level,with the increase of magnetic field,in the vertical direction of the level,magnetic particles form the small chains and then become the large chains along the magnetic field,finally,all are in the arrangement of chains or columnar chain.The results of this study can provide a theoretical basis for optimizing MRF parameters and design of high-performance MRF devices.