A high-order finite element for dynamic analysis of soft-core sandwich plates

The dynamic behavior of soft-core sandwich plates is investigated. A high-order finite element concept that has been developed for the dynamic analysis of multi-layered plate structures with stiff and compliant layers is applied to the soft-core sandwich plate. The application to sandwich plates aims to validate the general model through comparison with experimental and analytical benchmarks and to throw light on the unique structural response of the sandwich plate. The model introduces the core's three-dimensional stress and deformation fields using a high-order kinematic assumption that is based on the closed-form solution of the static governing equations of the core. The first-order shear deformation laminated plate theory is used for the face sheets. The combination of the high-order theory with the finite element concept aims to extend the application of the theory to more general layouts, to reduce the computation effort needed for a three-dimensional analysis, and to address some of the obstacles due to differences in length scales and elastic properties. The validity and the capabilities of the formulation are examined through comparison with experimental and analytical results taken from the literature. In addition, the static, free vibration, and dynamic behaviors of an 'L' shaped sandwich plate subjected to localized loads and boundary conditions are numerically studied. The formulation, the comparison with experimental and analytical benchmarks, and the numerical study highlight the three-dimensional effects and reveal unique aspects of the dynamic response of soft-core sandwich plates.