Nonlinear Vibration Characteristics Test And Parameters Identification Of Hard-coating Composite Structure

Hard-coating is the coating material which is made of metal base,ceramic base or mixture of both.Study in recent years found that,the hard-coating has received more attention and further research because of its good damping vibration reduction ability,have high temperature resistance,corrosion resistance,friction resistance and the characteristics of anti-scouring.Hard-coating material has the characteristics of amplitude dependency,its elastic modulus will change with the vibration amplitude.Because hard-coating materials have the characteristics of the above,the composite coating structure can produce unique mechanics phenomenon,which is usually characterized by soft nonlinear stiffness.This paper aims at the soft stiffness nonlinear of composite hard-coating structure,which researches characterized test,parameters identification,and dynamics modeling based on the phenomenology.The main research contents of this paper are as following four aspects:First of all,characterization testing is completed for the composite hard-coating structure.On the basis of providing nonlinear system characteristics and nonlinear test method suitable for composite hard-coating structure,the test process is determined for composite hard-coating structure,characterization testing is completed for the composite hard-coating structure coated by NiCrAlY + YSZ,frequency domain and time domain response is obtained which can describe the nonlinear vibration phenomenon of hard-coating plate.Then,the method from the view of time domain to identify the nonlinear stiffness and damping parameters of composite hard-coating structure is put forward.Based on the EMD decomposition and the Hilbert transform,formula to identify the nonlinear stiffness and damping of composite hard-coating structure is deduced,the process of parameters identification is determined.A case study is completed,which has identified the nonlinear stiffness and damping of the composite hard-coating structure coated by NiCrAlY + YSZ.Moreover,the method from the view of frequency domain to identify the nonlinear stiffness and damping parameters of composite hard-coating structure is put forward.On the basis of revising the classic half power bandwidth method,a method to identify the nonlinear stiffness and damping of composite hard-coating structure is developed,the process of parameters identification is determined.A case study is completed also,which has identified the nonlinear stiffness and damping parameters of the composite hard-coating structure coated by NiCrAlY + YSZ.Finally,based on the soft stiffness nonlinear frequency response of the test for the hard-coating titanium plate,on the basis of phenomenology dynamics modeling method is studied.Taking an example of coating plate,the dynamic equation of the composite hard-coating structure modal vibration has been deduced,the mathematical model of the composite hard-coating structure vibration in the of modal coordinates is established.The identification parameters obtained from the previous section is given,the dynamics modeling of the hard-coating titanium plate which is based on the experimental phenomena has come true.Of this study can be for hard coating composite structure and parameter identification of nonlinear vibration characteristics,provide reference,can also be used for the anti-vibration design of hard coating composite structure to provide support.This study can provide the reference for nonlinear vibration characteristics and parameter identification of composite hard-coating structure,it can also be provide support for the anti-vibration design of composite hard-coating structure.