Effects of nonlinear coatings on vibration characteristics of rotating blisks with mistuning features

Abstract

Hard coatings have been investigated to control the vibration level of nonrotating blisks. Nevertheless, the rotational effects in previous investigations of coated blisks are neglected. In this work, a linear reduced order model on the basis of an improved cyclic symmetric analysis method and classical SNM (Subset of Nominal Modes) is present to simulate rotating blisks with linear coatings and mistuning features. Furthermore, the nonlinear reduced order model of rotating blisks incorporating nonlinear characteristics of coatings and mistuning features is developed. The nonlinear forced responses are solved by a developed accelerated iteration method. The effects of nonlinear coatings on vibration characteristics of rotating tuned blisks are investigated. Finally, deterministic and statistical analyses are performed to analyze the effects of the nonlinear characteristics of coatings on forced responses of rotating randomly mistuned blisks. The results indicate that considering the nonlinear characteristics leads to increasing reduction level of forced responses with the increment of excitation amplitude and the rotational effects play an important role on the vibration characteristics of the blisks.