2008 Volume 8 Issue 3 Pages 270-275
By using a damper with a magnetic functional fluid, we can change damping force without using any complicated mechanisms. Magnetorheological fluids and magnetic fluids are generally used for the damping force variable damper. The particles in the magnetorheological fluids subside immediately, and the magnetic fluid does not have high saturation magnetization, while it is expected that the magnetic functional fluid including both magnetic particles of micrometer size and magnetic particles of nanometer size outperform them. When the magnetic functional fluid that has two kinds of particles of different size is used, the mixture ratio of the particles affects damping properties of the damper. On the other hand, wide range of damping force and quick response are important properties for the damping force variable damper. In this study, damping properties of a damping variable damper are investigated experimentally. Five magnetic functional fluids that mixture ratios of a magnetic fluid and magnetorheological fluid are different were prepared for the experiments. Poly-α-olefin was used for the solvent of the magnetic functional fluids. It is shown that the damping force, shape of the damping force-displacement curve, the absorption energy and the damping force response are affected by the mixture ratio of the magnetic fluid and the magnetorheological fluid.
