Research On The Aero-thermo-elastic Vibration Modeling Method And Characteristic Analysis Of Functionally Graded Plates

The siding structure is widely used in the fields of ship engineering,aerospace engineering,and mechanical engineering.In engineering practice,the working environment of the siding structure is relatively complicated,and it will present complex dynamic characteristics under the combined action of thermal,mechanical and aerodynamic loads.When the thermal stress reaches a certain value,it will cause thermal buckling of the structure,and when the aerodynamic pressure reaches a certain value,it will cause the structure to flutter.Thermal buckling and chattering can cause fatigue failure of wall panels and lead to system failure.Functionally graded material,as a new type of non-uniform composite material,overcomes the stress concentration phenomenon of traditional laminated materials,and effectively reduces the failure rate of structural caused by material properties.Therefore,it is of great engineering significance to study the coupled vibration characteristics of functionally graded plate structures in the gas-thermal-elastic environment.The main contents of this article are as follows:Based on the classical plate theory and the third-order shear deformation plate theory,a functionally graded plate dynamics analysis model was established.The boundary spring was used to simulate arbitrary boundary conditions of the structure,and the Rayleigh-Ritz method was used to obtain the free vibration characteristic of the elastic plate structure.By comparison with the literature,the convergence and accuracy of the two theoretical models are verified under different conditions.Based on this,the calculation accuracy of the two theoretical models is compared and analyzed,and the applicable range of the two theoretical models is given.Aiming at Ti-6Al-4V/Zr O₂,Si₃N₄/SUS304,Nickel/Zr O₂functional gradient materials,the influence of boundary conditions,volume fraction index and width-thickness ratio on the vibration characteristics of elastic plate structures was studied.An analytical model for the vibration characteristics of functionally graded plate structures under thermal conditions is established.Considering two temperature loads of uniform temperature rise and non-linear temperature distribution,the temperature load is taken into the overall energy functional through the nonlinear strain term of the structure,and the thermal-elastic coupling vibration Governing equation of the functionally graded plate structure is derived by Rayleigh-Ritz method.Based on the analysis of the model’s convergence and correctness,the effects of factors such as volume fraction index,temperature rise conditions and boundary conditions on the thermal vibration characteristics of functionally graded plates were studied.Based on the third-order shear deformation plate theory and the first-order piston theory,a dynamic analysis model of the supersonic functional gradient plate in the gas-thermal-elastic environment is established.By comparison with different literatures,the convergence and correctness of the method in this paper are verified when dealing with isotropic plates and functional gradient plates.Based on this,a series of research work has been carried out on the gas-thermal-elastic coupling vibration characteristics of functionally graded plate structures in complex environments.The effects of volume fraction index,thermal boundary conditions,and geometric parameters on the flutter characteristics of elastic plate structures are mainly studied.