Pre-yield shearing regimes of magnetorheological fluids

Waad Nassar (1, 2) , Xavier Boutillon (1) , José Lozada (2)

1 LMS - Laboratoire de mécanique des solides
2 LIS - Laboratoire Interfaces Sensorielles

We analyzed experimentally the pre-yield regime of some MRFs. The hearing response is ruled by two successive regimes and limited by an interfacial phenomenon. The initial response is pseudo-elastic and independent from the magnetic field and of the particle volume fraction. The shear-stress limit of this regime is proportional to the square of the magnetic field and to the particle volume fraction. In the next regime, the shear strain is not uniform in the fluid. The increase in average shear stress varies linearly with the increase in average shear strain. The variation coefficient is proportional to the square of the magnetic field and decreases with the particle volume fraction. Finally, a loss of adhesion of the magnetic aggregates with the shearing plate or the magnetic pole occurs. The corresponding shear stress is proportional to the square of the magnetic field and to the particle volume fraction.

Domains: Engineering Sciences [physics]; Mechanics [physics.med-ph]; Mechanics of materials [physics.class-ph]; Physics [physics]; Mechanics [physics]; Mechanics of materials [physics.class-ph]

Waad Nassar, Xavier Boutillon, José Lozada. Pre-yield shearing regimes of magnetorheological fluids. SMASIS2012, Sep 2012, United States. 6 p. ⟨hal-00817833⟩