Synthesis, characterization and selection of optimal constituents of magnetorheological fluid for damper application

Magnetorheological (MR) dampers are a category of energy dissipating devices that employ magnetorheological fluids which undergoes drastic change in its behaviour under the presence of magnetic stimulus. The damping characteristics of an MR damper predominantly depends on the dimensions of damper and on the constituents of MR fluid (MRF). In this work, an optimal MRF composition suitable for a monotube MR damper has been selected from six prepared MRF based on optimization. Initially, MR damper piston dimensions have been obtained by means of optimization. The damper has been fabricated and filled with commercial MRF 132DGTM fluid (Lord Corporation) and its performance has been tested. The experimental results have been validated with computational results. In the next part of the study, MRF samples composed of three particle weight fractions of fine and coarse-sized iron particles have been synthesized, and the rheological properties have been measured and compared with those of commercial MR fluid. The force-displacement characteristics of a damper employing synthesized MRF have been determined with and without the application of current to the damper coil. Finally, by means of the Multi-Objective Genetic Algorithm, optimum iron particle size and weight fraction have been selected from the pareto front solutions.