Stress state analysis of compressor blade-disk joint with the influence of centrifugal forces and blade mistuning

Abstract

The authors present the results of the numerical experiments on the determination of the effect of compressor blade mistuning on the stress state of a blade-disk joint under the action of the centrifugal forces and their comparison with results of full-scale experiments. The analysis of the results of the previously performed experimental and numerical experiments on the determination of the possible sources of blade-disk joints failure shows their stress state strongly depends on the disk rim thickness and the blade vibration mode and their mistuning. It indicates the need for further studies to determine the causes of cracks and possible fracture of blade-disk joints in the compressor of a gas-turbine engine. The task is solved in the variation of the dovetail-rim region thickness of the disk of the 1st stage of the low-pressure compressor of the gas-turbine engine D-36, which has blades without shrouds. The finite element models of the blade assembly, are used to perform the investigation. Obtained results of the vibration stress analysis of blade-disk joints in the compressor both modifications under the action of the centrifugal forces have good agreement with the data of full-scale experiments and numerical data using rod models. The presented results of the numerical experiments indicate the possibility of reducing vibration stresses by analyzing and choosing parameters that affect the rigidity of the coupling of the blades, which is of practical importance for increasing the vibration reliability of the compressors of gas-turbine engines.

Keywords

• робоче колесо компресора
• міжпазовий виступ диска
• розлад частот лопаток
• частотна функція
• відцентрова сила
• вібронапруженість