Numerical Analysis of Rotating Flexible Blade-Disk-Shaft Systems

Abstract

The theory, the algorithms and program package BLADIS (BLAded DIsk Simulation) for strength calculations of rotating flexible blade-disk-shaft assemblies have been worked out. The formulation is based on a finite element analysis of the rotating cyclic structures and modal reduction. The stresses in different zones of the structural components due to influence of centrifugal and temperature forces using static analysis and vibration are calculated. The results obtained show, how shaft flexibility influence on stresses and frequencies. Analysis of influence of blade geometric parameters on disk-shaft stresses is presented. The results obtained by dynamic analysis show that the chosen reduction does not reduce the quality of the model and illustrate its capability to deal with rotating shafts usually calculated using the rotordynamic approach. Finally, the possible dynamic interactions between shaft and disk components are described. This information is used for bladed disks and rotors optimization leading to a reduction of resonance displacements, stress levels and shifts of natural frequencies of rotating flexible blade-disk-shaft assemblies from dangerous resonances. The numerical results are carried in leading machine building companies in Russia.