Nonlinear effects of electrorheological fluids and their application in smart avionic systems

Abstract

Electrorheological (ER) fluids are not yet exploited within the aerospace industry, however, there are systems on an aircraft which would benefit from the use of this type of smart material and its associated technologies. The use of ER fluid within landing gear (LG) systems can be envisaged, for example the control of the passive damping characteristics of a landing gear oleo. This could be beneficial to the airframers by reducing LG weight, to the landing gear systems providers by reducing costs and over design, as well as for the operators by increasing passenger comfort and confidence. The use of ER fluid within an oleo would, however, result in a non-linear damper the characteristics of which would be dependent upon the design, the mode of deformation of the charged fluid and the control strategy. A design strategy is proposed for the use of ER fluid within a LG oleo and the controller design aspects considered.