Vibration Modes and Natural Frequency Veering in Three Dimensional, Cyclically Symmetric Centrifugal Pendulum Vibration Absorber Systems

Abstract

This paper investigates the vibration mode structure of threedimensional, cyclically symmetric centrifugal pendulum vibration absorber (CPVA) systems. The rotor in the system has two translational, one rotational, and two tilting degrees of freedom. The equations of motion for the threedimensional model, including the rotor tilting, are derived to study the modes analytically and numerically. Only three mode types exist: rotational, translationaltilting, and absorber modes. The rotational and absorber modes have identical properties to those of inplane models. Only the translationaltilting modes contain rotor tilting. The veering/crossing behavior between the eigenvalue loci is derived analytically.