Study On Vibration Characteristics And Reducing Vibration Of Aero-engine Mistuned Bladed Disc System

Difficult technique, involving amount investment and long period are considered as significant problems during the research and development of aero-engine. Aero-engine can produe a critical effect on performances and development progress of the whole aeroplane, and even an aeroplane whether can be developed successfully is greatly influented by aero-engine. Moreover, it can be well used in both military field and home application. So the research and development of aero-engine is of great significance to national defense and economy. However, bladed disc system which is the most important component element of aero-engine is sensitive to blades mistuning. Mistuning makes vibration energy of bladed disc concentrate on some few blades, and this phenomenon is named vibration localization. This phenonmenon causes a great threat to reliability of entire aero-engine system. To sum up, it is necessary to predict accurately and reduce vibration effectively in mistuned situation.In this paper, mistuned bladed disks system of aero-engine was studied by the method of theoretical analysis and finite element simulation, and then a further research on vibration laws and reducing vibration methods to mistuning bladed disc system was developed.At the beginning, a lumped parameter model was established, and then effect of mistuned parameters on mode and response of bladed disc were obtained. Furthermore, based on the rules, a new parameter for characterizing vibration localization of mistuned bladed disc was proposed. Using ant colony algorithm, a optimization scheme concerning how to choose the installation arrangement of blades, was explored on given mistuned. In this light, that both reducing vibration and tuning amplitudes were considered makes each blade share vibration energy evenly so that the material fatigue of blades can be brought down and lifetime of entire system can be extended.Next, based on the microslip friction model, model of bladed disc system with nonlinear dry friction considered was established. Normal pressure of platform nonlinear friction damper was optimized and effects of platform nonlinear friction damper on vibration of bladed disc system were analyzed.Finally, vibration characteristics of mistuned bladed disc system were simulated and analyzed by general finite element program.Modal analysis of bladed disc system under different conditions was done, and the finite element component modal synthesis method was used to analyze bladed disc system.Effects of mistuning on vibration characteristics of bladed disc system were obtained.Vibration laws obtained and vibration reduction methods explored in this paper have certain practical and reference value in guiding the design and vibration troubleshooting of bladed disc system of aero-engine.