Vibro-Acoustic Behavior and Sound Radiation Characteristics of Double In-Plane Functionally Graded Plate–Cavity Coupling Systems with an Open Hole

Functionally graded (FG) plates are widely used in engineering problems, and the presence of open holes is inevitable in practical engineering structures; relevant research on vibro-acoustic behavior and sound radiation characteristics is essential. This paper presents a dynamic model for a double FG plate–cavity coupling system with an open hole. The physical properties of the two plates vary continuously in the in-plane direction. To account for the complex open-hole configuration accurately, isogeometric analysis (IGA) integrated with a multi-patch coupling approach is employed. On the basis of the first-order shear deformation theory (FSDT), the governing equations for the double in-plane FG plate–cavity coupling system with an open hole are formulated by combining energy variational principles. The vibro-acoustic characteristics of this coupling system can be obtained by solving the governing equations, and then the sound radiation is computed using the Rayleigh integral formulation. In numerical analysis, the accuracy of the present model is validated through comparisons with the traditional finite element method (FEM). Subsequently, the influences of the open-hole shape, geometric size, and material properties on vibro-acoustic behavior and sound radiation performance are assessed. This research can provide theoretical guidance for optimizing FGMs and designing open-hole configurations in the future.