The evaluation of the effect of strain limits on the physical properties of Magnetorheological Elastomers subjected to uniaxial and biaxial cyclic testing

Abstract

N., Ekins R., et al. (2017). The evaluation of the effect of strain limits on the physical properties of Magnetorheological Elastomers subjected to uniaxial and biaxial cyclic testing. Title: The evaluation of the effect of strain limits on the physical properties of Magnetorheological Elastomers subjected to uniaxial and biaxial cyclic testing. Authors and AffiliationsDave Gorman, Niall Murphy, Ray Ekins, and Stephen Jerrams Dublin Institute of Technology Dublin 1 Corresponding Author Dave Gorman david.gorman@dit.ie AbstractMagnetorheological Elastomers (MREs) are "smart" materials whose physical properties are altered by the application of magnetic fields. In a previous study by the authors [1], variations in the physical properties of MREs have been evaluated when subjected to a range of magnetic field strengths for both uniaxial and biaxial cyclic tests. By applying the same magnetic field to similar samples, this paper investigates the effect of both the upper strain limit and the strain amplitude on the properties of MREs subjected to cyclic fatigue testing. As the magnetorheological (MR) effect is due to the dipole-dipole interactions of the magnetic particles in an MRE [2], it is expected that the larger the upper strain limit, the lower the overall MR effect will be. This is investigated by varying the upper strain limit between tests while keeping the magnetic field applied during testing at selected cycles constant between tests. To investigate if the MR effect is only dependent on the upper strain limit and the magnitude of the applied magnetic field during cyclic testing, the tests are repeated with the same upper strain limits and applied fields but with reduced strain amplitude.

An Overview of Durability Evaluations of Elastomer-Based Magnetorheological Materials

“…According to the literature surveyed on the durability of MRE, circular disk design was the highest employed geometry for the MRE durability test. The radius of ranged between 13 mm [34] to 60 mm [36] was used, however 50 mm [14], [16], [17], [19], [24], [31] was the commonly been practiced. This may due to the requirement of the sample mounting devices from the test machine itself, such as the Modular Compact Rheometer (MCR) and the bi-axial test device.…”

“…In the MRE durability test, the Beam-liked specimen was then the closest following number of geometries that have been used. Researchers [16], [19] used this specimen for the uniaxial tensile fatigue test in the method for specifying the magnetic field applied during MRE durability testing. The other researchers worked in MRE durability test, however used unfamiliar test geometry such as cube [21], [22], [33], rectangular [20], [25], [27] and cylindrical [22].…”

“…Presently, evaluation of MRE durability can be categorized into less than ten types of analyses compared to the rubber or its similar off-state behavior materials. Among the analyses, cyclic loading was the most employed by researchers [15], [16], [19]- [23], [25], [26], [35], [37] in evaluating MRE durability. The cyclic loading applied to the sample was in tensile, compression, and shearing continuously for various increasing numbers of cycles.…”

Compressive properties of magnetorheological elastomer with different magnetic fields and types of filler

“…Schümann et al studied mechanical properties on timescales of electroconductive MREs . Gorman et al studied the effect of strain limits on properties of MREs under uniaxial and biaxial testing . Danas et al studied the theoretical and experimental aspects of iron‐filled MREs .…”

“…29 Gorman et al studied the effect of strain limits on properties of MREs under uniaxial and biaxial testing. 30 Danas et al studied the theoretical and experimental aspects of ironfilled MREs. 31 Jung and An et al studied the MRE composites based on natural rubber, carbonyl iron particles, or modified silane-coated carbonyl iron.…”