Characteristics of a Liquid-Crystal Type ER-Fluid Variable Damper for Semiactive Vibration Suppression

Abstract

A liquid-crystal type ER-fluid variable damper was fabricated to semiactively suppress the vibration of space truss structure. The principal characteristics of a liquid-crystal variable damper were measured in quasi-static tests, and a simple mathematical model of the damper was proposed. Semiactive control laws were derived from this model and the LQR theory. Numerical simulations were performed to compare the effectiveness of the semiactive vibration suppression using liquid-crystal type and particle-dispersion type ER-fluid variable dampers. The results indicated that the proposed control laws resulted in much better damping performances than is obtained with an optimally tuned passive system. In some cases such as large amplitude vibration, a variable damper using liquid-crystal type ER-fluid showed higher performance than one using particle-dispersion type ER-fluid. The results of semiactive vibration suppression experiments with a ten-bay truss beam also demonstrated that the liquid-crystal variable damper effectively suppresses vibration. [S0739-3717(00)00304-4]