An investigation of the behaviour of magnetorheological fluids in compression mode

Magnetorheological (MR) fluids based on iron micro-particles in a carrier fluid, water and hydrocarbon were investigated under various factors. DC electrical current was supplied to a coil in order to generate a magnetic field. Experimental trials were carried out by lowering the upper cylinder towards the lower cylinder and simultaneously compressing the material in between them. Results showed that both materials experienced unique behaviours as demonstrated by the stress–strain curves, which can be divided into three regions. Initially, the stress–strain curve increased progressively, then transformed to plateau and finally proceeded to increase intensely. The curve of water-based MR fluid was developed hastily and showed a higher compressive stress over compressive strain as compared to hydrocarbon-based MR fluid. Compressive speed has no significant effect on the stress–strain curves even at a very high speed. A higher value of stress versus strain was obtained by applying a higher current. The curves are well fitted and overlapped to each other under the influence of compressive speed or applied current. It has been observed that a linear relationship can be established at the first and third regions. At the second region, the compressive stress exhibits no progress as the compressive strain continues to increase.