Vibroacoustic feature of three-dimensional angle-graded auxetic honeycomb metastructures using acoustic point source excitation

This study investigates the effect of a 3D angle-graded auxetic honeycomb core (AGAH) on enhancing the acoustic insulation characteristics of a finite metastructure subjected to spherical wave excitation. Firstly, 3D elasticity theory is applied to utilize the state vector approach in order to derive transfer matrices, which are then used to compute sound transmission loss (STL) of the metastructure. To determine the unknown variables, appropriate boundary constraints are imposed, resulting in a formulated expression for determining the STL within the system. The generated governing equations are then evaluated computationally using MATLAB software to analyze how the acoustic wave properties affect the structure. Analysis shows that using a point source instead of a plane wave greatly affects the STL evaluation. The study also highlights the importance of acoustic core and cell type selection in optimizing the STL. Specifically, the results demonstrate that the implementation of this advanced acoustic core enhances the STL by approximately 53.7% at lower frequencies. Furthermore, accounting for spherical wave excitation offers a more precise representation of the panel’s acoustic performance, with a notable reduction in the STL observed under this context. These insights contribute to a deeper understanding of acoustic behavior, enabling more effective design strategies for noise control applications.