Experimental study of the magnetic field enhanced Payne effect in magnetorheological elastomers

Abstract

The dynamic modulus and the loss factor of magnetorheological elastomers (MREs) of various compositions and anisotropies are studied by dynamic torsion oscillations performed in the absence and in the presence of an external magnetic field. The emphasis is on the Payne effect, i.e. the dependence of the elastomer magnetorheological characteristics on the strain amplitude and their evolution with cyclically increasing and decreasing strain amplitudes. MREs are based on two silicone matrices differing in storage modulus (soft, G' ∼ 10(3) Pa, and hard, G' ∼ 10(4) Pa, matrices). For each matrix, the concentration of carbonyl iron particles with diameters of 3-5 μm was equal to 70 and 82 mass% (22 and 35 vol%, respectively) in the composite material. Samples for each filler content, isotropic and aligned-particles, are investigated. It is found that the Payne effect significantly increases in the presence of an external magnetic field and varies with the cyclical loading which reaches saturation after several cycles. The results are interpreted as the processes of formation-destruction-reformation of the internal filler structure under the simultaneously applied mechanical force and magnetic field. Impacts of matrix elasticity and magnetic interactions on the filler alignment are elucidated.

The Magneto-Mechanical Behavior of Active Components in Iron-Elastomer Composite

“…The self-assembly model is used to explain the microstructure of iron particles in the MRE composites, as shown in Figure 14 in agreement with literature [18,19]. The isotropic distribution of filler particles facilitates microscopic behavior changes within the MRE composite, thus resulting in affine coupling of the particles, likely following the two-particle model, within the broad dimension of the macroscopic deformation of the samples [9,15]. The effect of the formation of a self-assembled microstructure is observed in the isotropic distribution of the MRE composite, which agrees well with our previous data [20].…”

Magnetorheological Payne effect in bidisperse MR fluids containing Fe nanorods and Fe3O4 nanospheres: A dynamic rheological study

“…Loss factor or tanδ (G′′/G′) also increases rapidly in this region till it gets independent of strain. Although the effect was first demonstrated for rubber-polymer networks, similar trend was also reported recently for magnetic elastomers and polymer blends [7]. The term the "magnetic Payne effect" was first coined by An et al for MR gels to highlight their strain-softening [8].…”

“…It is seen that the dynamic breakdown and reformation of fractal network comprised of nanospheres and nanorods with increasing deformation gives rise to magnetorheological Payne effect, similar to that of carbon-filler containing rubber matrix [7]. The hydrodynamic interaction between filler networks in carbon-rubber filler gives rise to stress relaxation phenomenon [6].…”

“…But as the vol% of Fe increases, significant and pronounced variation is observed. This is principally due to the breakdown of aggregated networks at higher strains [7,8]. With increasing strain, unperturbed chains of magnetic particles start to crumble.…”

Strain-dependent dynamic compressive properties of magnetorheological elastomeric foams

“…Generally, elastomers with hard particle fillers present strain-dependent dynamic stress behaviors or the so called "Payne effect". [3][4][5] The Payne effect results from the cyclic agglomeration and de-agglomeration of the filler particles. A large number of nano-sized particles form rigid aggregates because of Van der Waals attractive forces between particles and such aggregates again fluctuate to larger agglomerates (such as filler networks or clusters).…”