Analysis Of Whole Engine Response Due To Blade Out Load Of Aeroengine

High bypass ratio turbofan engine fan blade out(FBO)event is one of the most important threat to modern aviation flight safety.Due to the high strain rate,large deformation,strong coupling between structure parts and various non-linear factors,it's very complex to understand the phenomenon.In this paper,tests and simulation analysis were conducted,and the load transmission and whole engine response of aeroengine under FBO were analyzed,to provide methods for safety evaluation of turbofan engine.The main research contents and results of this paper are as follows:(1)Fan blade out simulation test bed was designed base on typical high bypass ratio turbofan engine structure.Fan blade out tests were conducted under different rotational speed,during the tests,a high-speed camera was use to capture the images and the acceleration data of the key locations was recorded.The experiment phenomena are: first impact of the released blade tip on the fan casing,impact of the released blade on the trailing blade as the rotor keeps on rotating,impact of the released blade root on the fan casing.The sequence of the acceleration response amplitude at different location is: fan case>middle case>turbine case,and the amplitude increase with the release speed.(2)3D finite element model of the test system was established in preprocess software Hypermesh,transient numerical simulations were carried out using explicit finite element software LS-Dyna,and the results were compare with experiment.Blade impact process in the experiments was well simulated.The tendency of acceleration response in the simulation was similar to experimental results,the validity of the simulation method was verified.However,there were some errors in the acceleration response amplitude.(3)Simplified model of a real high bypass ratio turbofan engine including the main load-carrying frame and low pressure rotor,was built,and FBO transient numerical simulation was conducted using the method developed above.Load distribution of key parts,such as blades,casing,bearings and load-carrying frame structure etc,was obtained.The research results presented in this paper provide analysis method for further safety analysis of high bypass ratio turbofan engine under FBO.