Multi-duct electrorheological dampers

In a cylindrical configuration, ER devices can be created by forming multiple flow paths with a set of concentric annular ducts. These ducts can be connected in parallel to maximize the range of adjustable forces or in series to maximize the absolute force levels. A synergistic result is obtained when groups of ducts are interconnected in parallel and in series within a single device. This paper presents the details of the design, construction, testing, and modelling of ER dampers designed in this fashion. These ER dampers feature multiple concentric electrodes which are electrically in parallel, but may be hydraulically inter-connected through multiple paths. The number of possible interconnections of N concentric ducts is 2(N-1). Each configuration has distinctly different properties. An analysis of these device configurations is completed in closed form by virtue of a linear approximation to the non-Newtonian ER Poiseuille flow equation. These analyses show that high-force ER devices which require low energy, and respond quickly, are feasible. The three ER damper designs described in this paper span a range of performance criteria. A mechanistic evolutionary model captures the frequency-dependent behaviour of these devices, whereas a frequency-independent algebraic model misses some of the frequency dependent dynamics.

Duke Scholars

Author Henri P. Gavin Civil and Environmental Engineering