Abstract
A bespoke test rig has been designed to facilitate testing of magneto-rheological (MR) elastomers (MREs) under equi-biaxial tension using a standard universal test machine. Tests were performed up to 10% strain on both isotropic and anisotropic MREs with and without the application of an external magnetic field. Assumptions regarding the material’s response were used to analyse stress–strain results in the two stretching directions. The assumptions have been verified previously by uniaxial tension tests and by simulations of the magnetic flux distribution performed using a commercial multi-physics finite element software. The MR effect, which is defined as the increase in tangent modulus at a given strain, has been studied versus engineering strain. The latter was measured optically in the experiments using a digital image correlation system. Relative MR effects up to 74% were found when the particle alignment of anisotropic MREs was oriented parallel to an applied magnetic induction of just 67.5 mT.
Highlights
Magneto-rheological elastomers (MREs) are smart materials which can alter some of their properties reversibly and almost instantaneously by the application of external magnetic fields
Anisotropic MREs with particle alignment in the y-direction were tested with a magnetic induction applied in the y-direction, the direction of the particle alignment was parallel to the main magnetic field direction; the setup is shown in figure 3(c)
The relative MR effects of anisotropic MREs with the magnetic field applied parallel and perpendicular to the particle alignment direction are plotted versus strain in figure 16
Summary
Magneto-rheological elastomers (MREs) are smart materials which can alter some of their properties reversibly and almost instantaneously by the application of external magnetic fields. This behaviour is caused by the interaction of micron-sized magnetic particles dispersed in an elastomeric material. In order to develop constitutive models able to accurately describe the complex behaviour of MREs comprehensive datasets are required. This involves testing both in the absence of and in the presence of magnetic fields, under various deformation modes, including multi-axial deformations, all on the same type of material [10, 11]. The number of independent parameters increases with the number of invariants; in order to uniquely
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
