Dynamic response of acoustically excited plates resting on elastic foundations in thermal environments

In order to ensure integrity of thermal protection system for hypersonic vehicles, the random dynamic response induced by the combination of the thermal and acoustic loadings has been investigated for a composite thin skin panel resting on a two-parameter elastic foundation. A theoretical model is developed based on the first four symmetric plate modes through Galerkin method. The solutions of a set of the high-order coupled ODEs have been validated by comparison of the postbuckling deflection with the results obtained from FEM postbuckling analysis. A dynamic response evolution parameter deduced from the primary-mode modal equation is used to characterize a transition from linear vibration to fully nonlinear dynamic snap-through. The study demonstrates the combination of acoustic excitation, thermal effect and structural stiffness governs the dynamic response evolution. As the elastic foundation stiffness increases, the buckling temperature increases and the postbuckling deflection decreases, which promote the nonlinear dynamic snap-through response remarkably with reducing snap-through amplitude.