Multilevel finite element modeling and coupling vibration analysis of the drum in blade-disk-drum assembly

Abstract

Blade-disk-drum (BDD) assemblies are commonly used in rotors of aeroengine. This paper investigates the vibration characteristics of the drum in the BDD assembly. In the analysis, multilevel modeling method based on ANSYS software is proposed. Free vibrations of single drum, disk-drum assembly, and the BDD assembly are calculated and carefully examined to discover the special modal shapes and coupling effects. Then according to the working environment, equivalent aerodynamic loads are imposed on blades and the drum respectively, to explore the vibration behaviors of the drum in the BDD assembly. Results reveal that, vibration of the drum, which may result in rub-impact or/and fatigue failure, can be induced by coupling vibration result from the aerodynamic loads on blades and drum, as well as the drum-dominant mode triggered by the aerodynamic loads on drum.