Effects of Pre-Stressed Conditions on the Dynamic and Acoustic Behavior of Composite Sandwich Panels

Lightweight sandwich panels are widely used in aeronautical engineering for their high specific strength, stiffness, and multifunctional performance. Their applications have expanded from interior components to secondary and even primary load-bearing structures, as they offer excellent acoustic insulation and cabin noise and vibration reduction. Recent research focuses on enhancing acoustic performance through modified core materials, geometries, or absorptive layers. The present work is devoted to the development of high-fidelity multilayered plate models within the Carrera Unified Formulation (CUF) methodology, including the description of the physical nonlinearities of soft cores using a hyperelastic constitutive law. Within this framework, the linearized modal and frequency response analyses of lightweight sandwich structures with soft cores are proposed, examining the influence of prestress on natural frequencies, transmission ratios, and overall dynamical properties.