Transmission loss investigation of acoustic metamaterials via Adaptive Finite Elements

This work develops the integration of the Rayleigh’s integral method for calculating transmission loss into a new class of 2D finite elements, the adaptive finite elements. These elements, recently developed within Carrera’s Unified Formulation framework, allow 2D structures to be studied independently of expansion along the thickness, allowing for increased computational efficiency over traditional solid elements. In this paper, they are used to calculate the transmission loss on a panel of sandwich material. The aim is to demonstrate their efficiency within a future core geometry optimisation process. These elements make studying different thickness geometries accurate and fast, always based on the same 2D mesh. The article briefly presents the formulation of the adaptive finite elements and Rayleigh’s integral method. Then, the implementation is validated, and a series of geometries chosen as examples are studied by calculating their transmission loss.