Investigation of Mechanical Performance of Squeezed Magnetorheological Fluid Using Response Surface Method

In this paper, effects of critical parameters, namely initial gap, squeezing speed and applied current were statistically investigated on the mechanical behaviour of MR fluid in squeeze mode. A set of 17 experiments was designed using Design Expert 7 software to gather data from response surface methodology (RSM). The responses in terms of compression modulus were then calculated. An MRF132-DG was used as a sample in each experiment. The experiments were conducted under compression stress mode using universal testing machine (UTM). Stress-strain curves were analysed using the machine integrated TestXpert analyser software package. The stressstrain curves of MR fluid under squeeze have produced a shear thickening behaviour at 13.54 MPa of the highest stress at 0.75 of strain. A correlation between the three parameters and the stressstrain properties was specified. The results showed that the initial gap and supplied current were significantly produced a high compression modulus for the MR materials. These findings are important to enhance the capability of the squeeze MR devices to operate at its best performance. High compressive stress is crucial for most magnetorheological (MR) materials, particularly in squeeze mode devices.