Abstract
An approximate solution of optimal parameters in the sense of H∞ optimization for a viscoelastic dynamic vibration absorber (DVA) attached to a damped primary system is derived. The viscoelastic DVA is described by the fractional differential Voigt model, which consists of a spring element and a non-integer-order derivative element in parallel. In the previous study, we derived an approximate solution of H∞-optimal parameters of the viscoelastic DVA for the displacement response of the primary system. The approximate solution was obtained by combining 1) a method in which the viscoelastic DVA is replaced by an equivalent viscous DVA approximately with 2) the fixed-points theory. In this paper, as the second report, we perform the H∞ optimization for the velocity and acceleration responses of the primary system, and derive an approximate optimal solution for design parameters of the viscoelastic DVA. The validity of the approximate solution is demonstrated by comparing the amplitude magnification when the approximate solution is used with that optimized numerically. Then, by analysis using the approximate solution, it is shown that the damping performance of the optimally designed viscoelastic DVA is slightly better than that of the optimized viscous one.
