Sound insulation properties of sandwich structure with hemispheric shell cores: Numerical and experimental studies

Sound insulation properties of sandwich structures have been extensively studied recent years. However, most of previous studies only focus on sandwich structures with cores of regular shapes. In this paper, a novel sandwich structure with complex curved shell cores, i.e. hemispheric shell cores (SSHSC), is first designed using a four-step strategy and fabricated via a 3D printer. Then, its sound transmission loss (STL) performance is investigated by utilizing the standing wave tube method. A 3D finite element model (FEM) with high fidelity is established to numerically investigate the STL of SSHSC based on the acoustic vibration coupling theory, which is verified by a serious of STL experiments. By using the validated FEM, we further investigate the influences of key geometric parameters of SSHSC on STL. Results demonstrate that the thickness of the panels significantly influences the STL and the thickness of the cores has relatively small effect on STL. The findings from this study can provide useful information for noise reduction applications of sandwich structures. (C) 2020 Elsevier Ltd. All rights reserved.