Software package to estimate turbomachine impeller mistuning effect on blade durability

The purpose of the present research is to develop a software package that allows to analyze the effect of turbomachine impellers oscillation detuning on their vibration frequencies and durability. The software package described in the article allows to analyze the frequencies of natural and forced oscillations, as well as the durability of gas turbine engine and other turbomachine impellers with parameter mistuning. The article presents the main provisions of the finite element method used in the analysis of oscillations and durability of gas turbine engine rotor elements (the algorithm for calculating their impeller durability is given). The software package is tested on test models. The comparison of test model calculation results and the results obtained in the ANSYS software package demonstrate a sufficiently small error that allows to use the developed software package to solve the analysis problems of the effect of turbomachine impellers oscillation parameter detuning on their vibrations and durability. In addition to the test models, the durability of a real impeller with Rolls-Royce integrated blades is calculated. The article shows the analysis results of the effect of parameter detuning introduced by material stiffness variation in different parts of the blades on blade durability. At the same time, the study is given to the several variants of blades with different values of Young's modulus for different parts of the blade and their combinations. Blade durability is calculated using different hypotheses of damage accumulation (Serensen, Corten - Dolan, Palmgren - Miner). The calculation results have led to a conclusion that even a small detuning can have a noticeable impact on impeller durability.

rotor blades, free oscillations, mistuning, program package, design, finite element method