Study of magnetorheology and sensing capabilities of MR elastomers

This study focuses on the magnetorheology and sensing capability of graphite based

Magnetorheological Elastomers (Gr MREs). By introducing graphite (Gr) to conventional

MREs, the Gr MREs are derived. The anisotropic sample with 20% graphite weight fraction

was selected to be compared with anisotropic conventional MREs. The microstructures of

anisotropic Gr MREs and conventional MREs were observed. Both steady state tests and

dynamic tests were conducted to study rheological properties of the samples. For dynamic

tests, the effects of strain amplitude, and frequency on both storage modulus and loss modulus

were measured. For sensing capability, the resistance of selected Gr MREs under different

magnetic fields and external loadings is measured with a multi-meter. Either higher magnetic

field or more external loading results in the resistance increment. Based on an ideal assumption

of perfect chain structure, a mathematical model was proposed to investigate the relationship

between the MRE resistance with the external loadings. In this model, the current flowing

through the chain structure consists of both tunnel current and conductivity current, both of

which depends on external loadings. The modelling parameters were identified and

reconstructed from comparison with experimental results. The comparison indicates that both

experimental results and modelling prediction agree favourably well.