Predicting Snap-through of a Thin-walled Panel due to Thermal and Acoustic Loads

摘要

Under contract from Wright-Patterson AFB (WPAFB), ATA Engineering, Inc., (ATA) has performed a study of 'snap-through buckling' of a panel on a hypersonic vehicle under the influence of fluctuating pressures. Snap-through occurs when the elastic stiffness of the structure is cancelled by the effects of compressive stress within the structure. If this effect causes the structure to suddenly displace a large amount in a direction normal to the load direction then it is classical bifurcation buckling. If there is a sudden large movement in the direction of the loading it is snap-through buckling. The analysis was performed by applying aerothermal loads and fluctuating pressure loads on a thin-walled panel. Representative metallic (Inconel X-750) panel structures have been defined. Uncoupled nonlinear computational structural dynamics (NLCSD) using Abaqus/Explicit simulations performed on these panels include their quasi-static deformation under the vehicle's aerothermal loads and their vibratory response to aerodynamic fluctuating pressure loads. The latter analysis has captured the phenomenon of snap-through response between two stable buckling equilibrium positions. The presenters will show the methods used and the results of this study, especially as it relates to the use of Abaqus.