Torsional Vibration Suppression by Using Wave Absorbing Filter

Abstract

The effect of the wave absorbing filter for torsional vibration system consisted of solid discs and torsional bars has been investigated both theoretically and experimentally. Two wave absorbing filters are developed based on the impedance matching condition, one is by introducing a 1-degrees-of-freedom imaginary system which has the impedance matching condition at an end (imaginary type), and the other is by changing the boundary condition to apply the impedance matching condition directly at the boundary (boundary type). The irrational transfer function of the impedance matching condition is numerically approximated as 6-order polynomials by using a curve-fitting technique. As the result of experiment both filters have shown to work very well compared to the authors' former wave control strategy(4) using a large degrees-of-freedom imaginary system and its initialization. The experiments of 2-and 3-degrees-of-freedom controlled system show the wave propagating state as the phase shift between adjoining elements, which correspond to the theoretical result. By comparing the effects of both filters, the boundary type is better than the imaginary type in the case without small sampling period, 4 ms in our experimental apparatus.