| At present,large-flexible support structures,such as squirrel cages,are widely used in the fields of high-speed rotating machinery such as aero-engines and turbines,to avoid the working area within the critical speed,Therefore,the rotor system is a typical bullet bullet supported-rigid rotor system.Compared with the traditional rotor system,the deformation energy mainly occurs in the supporting part,not the rotating shaft.However,this kind of rotor system often has problems such as installation misalignment and friction between the rotor and the casing caused by vibration at running time.The study of its dynamic model and the vibration phenomenon caused by it has become a hot topic in the research of aero-engine rotor system in recent years.It is a comparative study of the dynamic characteristics of aero-engine rotor system and plays an important theoretical support for rotor failure analysis.This paper takes the rotor system of the aeroengine fan section as the research object,establishes the analysis and rigid-flexible coupling dynamic model of the spring-loaded-rigid rotor system,and analyzes the influence of misalignment faults and rubbing faults on the dynamic characteristics of the spring-loaded-rigid rotor system.The main researches are as follows:(1)Establish the finite element model of the flexible-supported rigid rotor system with the rotor of the aeroengine fan section as the object,and derive the system dynamics equation,define the mechanical characteristics of the flexible-supported rigid rotor system,and analyze the mechanical characteristics of the rotor system by the change of support stiffness Impact.(2)Based on the theory of multi-body dynamics,the rigid-flexible coupling model of the bullet-supported rigid rotor system is established on the ADAMS and ANSYS software platforms,and the natural frequency and vibration mode of the rotor system are analyzed,and compared with the finite element and analytical models to verify Model accuracy.(3)On the basis of the above model,the fulcrum misalignment structure and mechanical model are introduced,and the dynamic model of the bullet-supported rigid rotor system with misalignment faults is established,and the angular misalignment and parallel misalignment under subcritical and overcritical conditions are analyzed.The influence of the dynamic characteristics of the elastically supported rigid rotor system is revealed,and the influence law of the misalignment on the rotor vibration and the elastic supporting structure is revealed.(4)Considering the changes in rub-impact stiffness,rub-impact damping,and rub-impact gap,a rub-impact failure model of the rigid-bolt-supported rotor system is established,and the dynamic characteristics of the rigid-rotor system under different rub-impact conditions are analyzed,revealing The vibration response of the rubbing fault on the rotor and the influence law on the elastic support;finally,the characteristics of the vibration response of the single-point rubbing and multi-point rubbing on the rotor system and the influence law on the elastic support are analyzed.This paper analyzes the mechanical characteristics of elastic support,and proposes a rigid-flexible coupling modeling method for the elastically supported rigid rotor system.Based on the ADAMS software platform,a rigid-flexible coupling model of the elastically supported rigid rotor system is established.The correctness of the model is verified and the analysis is incorrect.The impact of neutral and rubbing faults on the dynamic characteristics of the rotor system,the rigid-flexible coupling model of the elastically supported rigid rotor system and the simulation analysis results established in this paper have important engineering significance and reference value for the dynamics of the rotor system. |
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