Vibro-acoustic and buckling analysis of a thermal plate-cavity coupled system

In this paper, the vibro-acoustic and buckling characteristics of a rectangular plate-acoustic cavity system under thermal loads are studied. Both the structure material and the internal acoustic field are assumed to be temperature-dependent, with the acoustic cavity consisting of impedance walls. Considering the interaction between the structure and the acoustic cavity, the governing equations of the coupled system are derived and solved via the improved Fourier series and the Rayleigh–Ritz method. Vibro-acoustic modes in such a coupled system are strongly affected by the coupling among subsystems. With thermal loads being considered, we observe that this strong coupling effect can be triggered more easily, even for thick plates or relatively large cavities. To address this, a simplified formulation for the coupled fundamental mode is also given following the fully coupled modeling procedures. Also, it is found that coupling the plate with a cavity can delay the onset of structural buckling. Therefore, for strongly coupled systems, the buckling temperature of the substructure may be much higher than for uncoupled or only weakly coupled substructures, which may enhance the safety of the system in a thermal environment.