Mechanical Design Fabrication and Characterization of Magnetorheological Fluid Based Damper

Abstract

Presently, the hydraulic dampers are used in automobiles and friction dampers newlineare used in front-loaded washing machines to overcome mechanical vibrations. newlineThese are passive damper; it can only generate the constant damping force, newlinedue to constant viscosity, at a given velocity. The damping is also affected by newlineenvironmental conditions like temperature. Magnetorheological (MR) fluid is newlineconsidered as a smart fluid and in the presence of the magnetic field, the MR newlinefluid changes its viscosity and converts to semi-solid state of the initial liquid newlinestate. This phase change process is reversible and response time is very less. newlineThis phase change is due to the alignment of magnetic particles in the direction newlineof the field as well as the formation of columnar structure. By using this inherent newlineproperty, many applications of MR fluid are possible, but the most common newlineapplication is as an MR damper. newlineThree different types of MR dampers are possible. These are based on the flow newlinebehaviour of the fluid and are defined by (1) shear mode (2) flow mode (3) newlinesqueeze mode. Out of these, one which is used most of the real-life applications newlineis flow mode damper. Less work is focused on the shear mode damper (SMMD) newlinedue to the least amount of force it generates. Thus the preliminary approach in newlinethis thesis is to design and optimized shear mode damper using simulation newlinesoftware and GRG algorithm. Different dimensions like coil width, coil height newlineactive pole length and piston radius are optimized and the SMMD is fabricated newlinebased on the optimized dimensions. newlineThe performance of the SMMD is evaluated with force-time plot, forcedisplacement newlineplot, and force-velocity plot for a different weight fraction based newlineMR fluids. Maximum damping force achieved with SMMD is nearly 53N. Higher newlineweight fraction based MR fluid gives better performance in damper application. newlineThe iron particles used to synthesize the fluid is flake shaped particles, this is a newlineunique approach of using anisotropic particles rather than conventionally used newlinespherical particles. In this st