On the stability of pairs of subharmonic centrifugal pendulum vibration absorbers allowing a rotational mobility

Abstract

Centrifugal pendulum vibration absorbers (CPVAs) are passive devices used to reduce torsional vibrations in rotating machines. Previous works showed that a CPVA configuration with two pendulums oscillating in phase-opposition and at half the excitation frequency is efficient in reducing the rotor's vibrations. This paper deals with a new generation of CPVAs, in which the pendulums admit a rotational motion relative to the rotor in addition to the traditional translational motion. The aim of this study is to assess the dynamic stability of a particular subharmonic solution of CPVAs composed of several pairs of pendulum. To do so, a new method based on an analytical perturbation technique is proposed. It leads to more general conclusions than previous studies as the results are derived for CPVAs with any even number of pendulums. The validity of the analytical model is confirmed through a comparison with a numerical resolution of the system's dynamics, and new design guidelines are proposed.