Research On Several Key Technologies Of Sudden High-energy Load Test

Aeroengines may encounter extreme conditions or severe working conditions such as fan blade out(FBO)and bird strikes.These extreme conditions and severe working conditions result in sudden high energy loads in the aircraft structure,which can easily cause primary or secondary damage to its key components,systems,or the entire aircraft,seriously endangers the structural safety of the aircraft.However,the existing domestic test equipment can no longer meet the requirements of a real rotor sudden high-energy load test,so it is of great significance to design a sudden high-energy load test device and to study its key technologies.By referring to the characteristics of the low-pressure rotor system of a typical turbofan engine,this article designs a sudden high-energy load test device for a typical turbofan engine according to the principles of similar mechanical structure and dynamic characteristics.The designed rotor system has a high degree of similarity with the actual rotor in terms of critical speed and mode characteristics.The mechanical structure of the main unit of the test device is designed,and the design parameters of the high-speed flat belt drive are given.The test device is expected to withstand 200 kN centrifugal load of blade.The maximum speed is 12000r/min and the maximum outer diameter of the rotor is up to 800 mm.A high-energy load test for FBO was designed,and the effectiveness of fan and blade connection technology,FBO control technology,and sudden high-energy load unbalanced response measurement technologies were analyzed based on the test results.The results show that the disk is not damaged due to the loss of blades,and the test can be repeated many times.The error of the blade centrifugal load is within 3%,which meets the accuracy requirements of most sudden high-energy load tests.The eddy current displacement sensor can’t measure the vibration data of the rotor system completely after the blade is detached,because the centerline displacement of the rotor rapidly increases and exceeds the upper limit of the sensor range.Laser displacement sensor should be selected for measurement of centerline displacement of the rotor.Using impact force sensors can directly reflect the change law of the rotor support load.When the cone wall is not damaged,the load on the upper and lower fulcrum points increases as the blade centrifugal load,and the load on the lower fulcrum point increases significantly large.When the blade centrifugal load is large enough to fuse the cone wall,the load on the upper fulcrum measured by the force sensor is significantly reduced to 1/5 ~ 1/2 of the blade centrifugal load,and the load on the lower fulcrum is significantly increased to approaching or slightly exceeding the blade centrifugal load.The impact force sensor measurement effect is more obvious than the acceleration sensor.