Dynamic Response of Thin-Walled Structures to Thermal Loadings and Random Acoustic Excitations

Abstract

Hypersonic aircrafts are facing increasingly severe aerodynamic heating, noise and so on, which will lead to nonlinear vibration characteristics for thin-walled structures of hypersonic aircrafts. Considering the influence of thermo-acoustic loadings, finite element formulation of simply supported plate under combined thermo-acoustic loadings are founded, and vibration characteristics of simply supported plate under thermal loadings with temperature gradient and random acoustic loadings are investigated. According to finite element numerical method, modal frequencies, critical thermal buckling temperature difference, dynamic stress response of simply supported plates with temperature gradient under combined thermo-acoustic loadings were calculated before and after thermal buckling. The results show that three types of motion: random vibrations around initial equilibrium position in pre-buckling region, snap-through oscillations between two post-buckling equilibrium positions, nonlinear vibrations around one of the two post-buckling equilibrium position, and The RMS of nodes for different locations of the simply plate are obtained in pre-buckling post-buckling region, and it is shown that different interaction of tensile bend stress, compressive stress and compressive thermal stress lead to different RMS trends.