Test And Analysis Of Dynamics Characteristics Of Viscoelastic Damping Thin Plate Under Gas Excitation

Many components of aeroengine,for example,compressor blades and blisk,work in condition of air-excited vibration for a long time.These components become lighter and lighter.However,at the same time,the vibration of components also becomes fiercer and fiercer when them works.Excessive vibration not only can affect the efficiency of engine,but also cause components' fatigue failure.As a result,it can severely affect the reliability and the safety of the engine.The viscoelastic damping,as the most widely used method,is used in aviation to solve the problem frequently.Furthermore,it is challenging in the field of viscoelastic damping research to analyze what effects the viscoelastic materials have on components' vibration attenuation in condition of air-excited vibration.Viscoelastic damping thin plates are used as the subject in this paper.The finite element model of viscoelastic damping thin plate can be established based on the result of air-excited vibration test.The correctness and feasibility of the computational model also be illustrated to solve any other relevant problems.On this basis,what effects air-excited and viscoelastic materials parameters have on the vibration characteristics of viscoelastic damping thin plate can also be analyzed.The concrete research content is embodied in the following four aspects.Firstly,the vibration characteristics of viscoelastic damping thin plate was tested in the condition of air-excited vibration.The air-excited loads were imposed on the viscoelastic damping thin plate by use of air-excited vibration system,which makes viscoelastic damping thin plate under the condition of pulse excitation.After that,the natural frequency of the viscoelastic damping thin plate was tested by sweeping in the resonance zone.The vibration response can be tested by fixed frequency test based on the result of the sweeping.In addition,it came to a conclusion that the viscoelastic damping materials make an effect on reducing the vibration.Secondly,the air-excited loads were calculated by use of the CFD methods in order to ensure its value in subsequent finite element model.GAMBIT was used to model,and FLUENT was used to simulate.The result of air-excited loads can be obtained,which compared with the result of classical fluid mechanics to analyze the error between them at the same time.The rationality of the analysis can also be illustrated.After that,some factors were made a thorough inquiry that influenced the result of the loads.Thirdly,the elastic modulus and loss factor of viscoelastic damping materials were identified.The elastic modulus was identified by use of finite element iteration method,the loss factor was identified by use of energy storage and energy consumption analysis as well.In the end,complex elastic modulus model of viscoelastic damping materials was established.These parameters would be entered into subsequent finite element model.Eventually,The finite element model of viscoelastic damping thin plate in condition of air-excited vibration was established and analyzed.The modal calculation and harmonic response calculation were made by ANSYS,whose result would be compared with air-excited test.After that,some factors were made a thorough inquiry that influenced dynamics characteristics of viscoelastic damping thin plate.The relevant research results can be used as a reference for the design of viscoelastic damping vibration reduction in the field of thin-wall components that can be representative by areoengine blades,and can also support the analysis of dynamics characteristics of thin plates in condition of air-excited vibration.