Magnetorheological fluid composite structures

Claim 1

A flexible structural element in the form of a beam, panel, bar, or plate that includes a magnetorheological fluid comprising of a particle component containing 1.0 to 500 μm size paramagnetic, superparamagnetic or ferromagnetic particles in an amount equal to 5 to 50 percent by volume of the total composition, a carrier component having a viscosity of 1 to 100,000 centipoise in an amount equal to 50 to 95 percent by volume of the total composition, and a dispersant present in an amount of 0.1 to 20 percent by weight relative to the weight of the particle component, wherein the dispersant is selected from the group of ferrous oleate and naphthenate, metallic soaps, alkaline soaps, sulfonates, phosphate esters, stearic acid, glycerol monooleate, sorbitan sesquioleate, stearates, laurates, fatty acids, fatty alcohols, fluoroaliphatic polymeric esters and titanate, aluminate and zirconate coupling agents, and wherein said magnetorheological fluid is confined in place by containment layers within said structural element and at least a portion of two of said containment layers being capable of allowing a magnetic field to be applied to the fluid, wherein flexing of said structural element imparts shear and axial tension to said fluid, the magnitude of said magnetic field is selected for defining the complex moduli of said fluid and the resultant complex stiffness and damping characteristics globally distributed over said structural element and a permanent magnet or an electromagnet is contiguous with an end of said containment layers.