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Civil-Comp Proceedings
ISSN 1759-3433 CCP: 79
PROCEEDINGS OF THE SEVENTH INTERNATIONAL CONFERENCE ON COMPUTATIONAL STRUCTURES TECHNOLOGY Edited by: B.H.V. Topping and C.A. Mota Soares
Paper 83
Aeroelastic Modes for Nonlinear Panel Flutter at Elevated Temperatures X. Guo and C. Mei
Department of Aerospace Engineering, Old Dominion University, Norfolk, Virginia, United States of America Full Bibliographic Reference for this paper
X. Guo, C. Mei, "Aeroelastic Modes for Nonlinear Panel Flutter at Elevated Temperatures", in B.H.V. Topping, C.A. Mota Soares, (Editors), "Proceedings of the Seventh International Conference on Computational Structures Technology", Civil-Comp Press, Stirlingshire, UK, Paper 83, 2004. doi:10.4203/ccp.79.83
Keywords: panel flutter, aeroelasticity, nonlinear analysis, finite element analysis, supersonic speeds, composite plates.
Summary
Panel flutter is the self-excited oscillation of the external skin of a flight vehicle when
exposed to airflow along its surface. The use of linear structural theory indicates that there is
a critical dynamic pressure above which the panel motion becomes unstable. For large
deflections, the nonlinear effects, the induced mid-plane forces restrain the panel motion to
bounded limit cycle oscillations (LCO). At supersonic speeds, the skin panel temperatures
could reach several hundred degrees due to aerodynamic heating. Large aero-thermal
deflections of the skin panel may occur. With the presence of supersonic flow and
temperatures, four types of panel behavior are observed and they are flat and stable,
aero-thermally buckled but dynamically stable, LCO, and chaos.
The various classical methods start with the governing partial differential equations in
conjunction with the Galerkin's method (PDE/Galerkin) [1], and the finite element methods
start with the system equations of motion in physical structural node degrees of freedom [2]
for nonlinear supersonic panel flutter analysis. Both PDE/Galerkin and finite element
methods employ a reduced base approach to reduce the PDE or the finite element system
equations to a set of coupled nonlinear ordinary differential equations using vacuo natural
modes (NMs). It is commonly accepted that a minimum of six NMs is needed for converged
LCO of isotropic rectangular plates at zero yaw angle [1]. For isotropic or orthotropic
rectangular plates under an arbitrary nonzero yawed supersonic flow, 36 or 6
A major advance to further reduce the number of coupled nonlinear modal equations is
the use of aeroelastic modes (AEMs) [4]. With the presence of aerodynamic effects in the
NMs, which are the AEMs, only two to six AEMs are needed for converged LCO of
isotropic or anisotropic composite rectangular plates at zero or an arbitrary yawed flow angle [4].
This paper is the first time to extend the use of AEMs to nonlinear panel flutter analyses
considering both nonzero yawed supersonic flow and elevated temperatures. It is
demonstrated that only six AEMs are needed, instead of 36 (6 References
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