Investigation and modelling of damping mechanisms of magnetorheological elastomers

Abstract

Damping in MREs is considered to be ascribed to viscous flow of the rubber matrix, interfacial damping at the interface between the magnetic particles and the matrix and magnetism induced damping. In this study, individual components in MREs that contribute to material damping were investigated. A model was developed to include viscous flow of the rubber matrix, interfacial damping and magnetism induced damping to give the total damping capacity of MREs ψMRE( ψMRE)It was found that ψMRE depends on frequency, iron sand content, strain amplitude and ψMRE is independent of the applied magnetic field over saturation magnetization. The proposed model was assessed experimentally using a series of isotropic and anisotropic MREs. Comparison between tan δ with ψMRE showed that ψMRE matched the experimental trends with average percentage difference of 8.1% and 21.8% for MREs with modified iron sand unmodified iron sand, respectively. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43247.

Tailoring Performance, Damping, and Surface Properties of Magnetorheological Elastomers via Particle-Grafting Technology

“…Based on the literature, the topic of the damping of the MREs can still evoke a controversy—while in some papers it is stated that magnetic field does not have any remarkable effect on damping [45], other scientists claim that damping of the MREs changes due to the applied magnetic field [5]. Recently, Shuib et al [46] proposed a mathematical damping model, which matched well with the experimental trends showing that the damping capacity of the MREs is dependent on magnetic field up to magnetic saturation. Herein, the employed magnetic fields were still below the particle magnetic saturation [32], thus the total damping is further discussed as the average value of tan δ obtained through the whole H range.…”

“…Herein, the employed magnetic fields were still below the particle magnetic saturation [32], thus the total damping is further discussed as the average value of tan δ obtained through the whole H range. The total damping capacity of the MREs includes several mechanisms, namely damping by the viscous flow of the elastomeric matrix, interfacial damping, and magnetism-induced damping [46].…”

“…The first-mentioned mechanism is provided by the viscoelastic polymer matrix, which is typically characterized following the Kelvin-Voight model [46]. In the interfacial damping, two classes are distinguished.…”

“…In the interfacial damping, two classes are distinguished. The damping in the systems with strongly bonded interfaces (matrix molecules are bonded to the surface of the filler particles) can be attributed to the energy required to bring about viscous flow of constrained materials in the vicinity of the particle interfaces [46,47]. The damping in the systems with weakly bonded interfaces is caused mainly due to internal friction between the particles and matrix and can be estimated based on Lavernia’s analysis [48].…”

“…Recently, it was found that this damping mechanism can be significantly improved by the incorporation of the functionalized carbon nanotubes (1 wt %) into the body of the MREs [49]. Finally, magnetism-induced damping is represented by the energy absorbed to overcome magnetic interactions between the particles [46] and can be modelled as presented by Jolly et al [50].…”