Squeeze flow behaviors of magnetorheological plastomers under constant volume

Abstract

The squeeze flow behaviors (including compressive, tensile, and oscillatory squeeze behaviors) of magnetorheological plastomers (MRPs, a kind of solidlike magnetic gels) under different experimental conditions are systematically investigated. Both compression and tension processes can be classified as elastic deformation region, stress relaxation region, and plastic flow region. A squeeze flow equation is used to describe the compressive behaviors of MRP in plastic flow region from which the compressive yield stress can be obtained and compared. The results demonstrate that both compressive yield stress and tensile yield stress are sensitive to magnetic field, particle distribution, and particle concentration. The yield stress of MRP under squeeze flow is larger than that of MR fluids due to the existence of polymer matrix. Asymmetry of hysteresis loop is found under oscillatory squeeze mode. The oscillatory squeeze behaviors of MRP are also influenced by magnetic field and particle concentration, but the influence of particle distribution is not so obvious. The related results under three operational modes are compared and qualitatively analyzed, which are helpful for further understanding the MR mechanism in the solidlike magnetic gels.