TY - JOUR A1 - Sorokin, Vladislav V. A1 - Ecker, Eva A1 - Stepanov, Gennady V. A1 - Shamonin (Chamonine), Mikhail A1 - Monkman, Gareth J. A1 - Kramarenko, Elena Yu A1 - Khokhlov, Alexei R. T1 - Experimental study of the magnetic field enhanced Payne effect in magnetorheological elastomers JF - Soft Matter N2 - 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' similar to 10(3) Pa, and hard, G' similar to 10(4) Pa, matrices). For each matrix, the concentration of carbonyl iron particles with diameters of 3-5 mu m 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. KW - BEHAVIOR KW - CARRAGEENAN KW - DAMPERS KW - MODEL KW - SEALS KW - SENSITIVE ELASTOMERS KW - Shear modulus KW - VISCOELASTIC PROPERTIES KW - WIDE-RANGE MODULATION Y1 - 2014 U6 - https://doi.org/10.1039/c4sm01738b VL - 10 IS - 43 SP - 8765 EP - 8776 PB - ROYAL Society of CHEMISTRY ER -