Compare of time domain method with frequency domain method in nonlinear flutter analysis for panels of supersonic airplane

The nonlinear flutter responses of heated panels in supersonic airflow are studied. The aeroelastic model of three-dimensional panels considering thermal effect is established by the use of von Karman large deflection strain-displacement formulations, quasi-steady first-order piston theory aerodynamics and the principle of virtual work. A Mindlin-type three-node finite element (MIN3) discretization is performed in deriving the governing equations which are solved in frequency domain through the use of the linearized updated mode with a nonlinear time function approximation (LUM/NTF) method. For time domain analysis, the discretized dynamic equations of motion are transformed into nonlinear coupled-mode equations by using the proper linear modal coordinates. The amplitude and frequency of panel flutter response is calculated using both frequency domain method and time domain numerical integration. The numerical results show that the efficient frequency domain method can be used to predict nonlinear panel flutter characteristics when the flutter response is demonstrated as a simply harmonic limit cycle oscillation.