Combination of Homogeneous Electro-rheological Fluid and Multi- Electrodes Damper for A Better Control of Car Suspension Motion

Abstract

This study presents the design and performance evaluation of a new design of intelligent damper that can be used for semi-active vehicle suspensions.This damper is a modified version of anordinary model, for which electro-rheological (ER) technology was incorporated. The key features of this particular design are the use of an efficient homemade homogeneous organic/inorganic ER fluid together with four electrodes mounted electrically in parallel and could be excited separately and independently from each other.An electro-rheological fluid (ERF) was prepared using modified silica particles dispersed in silicon oil. Molecules with mesogens groups were grafted on the surface of silica using polymethylhrosiloxane (PMHS) as interface. A net improvement of the stability of the suspension was then observed with an appreciable ER effect. FTIR and Zeta potential measurements confirmed the silica surface change.The characteristics of the fluid and the damper are experimentally obtained. The results show that the damping ability could be easily increased by increasing the number of excited electrodes.Incorporating the ER damper into a quarter-car suspension system represented by a single-degreeof-freedom model show that the optimum between comfort and stability depends on the excitation frequency. Because a continuous varying damping device is difficult and expensive to achieve, the innovative idea to use a fragmented long electrode could be an original approach to deliver a stepped (discrete) damping which values are depending on the number of excited electrodes.