Research On Fault Identification And Location Technology Of Typical Blade-disc Structure

The aero-engine is known as the "heart" of aircraft,and the blade-disc plays a pivotal role in the normal operation of the engine.If the blade-disc fails,it poses a serious threat to the safe flight of the aircraft.It is very important to use the reasonable and effective damage detection method to identify the fault damage of the blade-disc structure.Aiming at the damage fault of the engine blade-disc,the three aspects including curvature mode,modal strain energy and experimental verification are studied and optimized,which provides the basis for fault identification and location of the blade-disc.Firstly,the research background and significance of aero-engine blade-disc damage are introduced,and the identification methods of damage faults at home and abroad are studied and analyzed.The theory of curvature mode and modal strain energy is introduced,which lays a foundation for the fault identification and location research of the blade-disc.The blade-disc structure of the aero-engine is simplified,and a three-dimensional blade-disc model is established.Secondly,according to the theory of vibration characteristics,the curvature modal identification model is established to identify different damage locations and different damage levels of the blade body and the leading edge of the blade-disc structure.An improved curvature recognition model is proposed to identify the end damage of the blade-disc.And the good recognition results are achieved.Based on the damage identification method of modal strain energy theory,the damage identification mechanism based on the modal strain energy change rate and the modal strain energy density difference theory is derived.The structural element fault is identified from the energy point of view,and the blade-disc model is taken as an example for analysis.At the same time,compared with the curvature mode,the recognition and location of the blade-disc faults from various angles are realized.Finally,the vibration test bench with the blade-disc as the object is built.The correctness and feasibility of the theoretical method are verified by comparing the data results of the faulted blade and the non-faulty blade,which provides a significant reference value for fault detection of aero-engine blade-disc.