Dynamic Instability Analysis of Internally Damped Rotors

This paper deals with the study of dynamic instabilities within rotating assemblies due to internal damping effects. In order to consider realistic mechanical properties, in terms of internal damping, a rheological model is associated to a general finite element beam approach, including transversal shear. After a description of the theoretical background (choice of internal damping model and equation of motion), an application illustrates the ability of the proposed model. The influence of damping on frequencies and on instability thresholds is investigated using a parametric study. Results are compared to those obtained from an analytical approach as well as from experiments.