Structural health monitoring of sandwich structures with cellulare core materials

The dissertation project is aimed to a Lamb wave based structural health monitoring of sandwich structures with a cellular core layer. Such structures are frequently used as lightweight structures in many applications due to their high strength and stiffness behavior. Because of their complex build-up the understanding of Lamb wave generation and propagation is much more difficult than in the case of conventional composite structures. In the project the finite element method is applied to analyze the Lamb wave propagation at different frequency ranges and in sandwich panels with different build-ups to better understand the details of wave propagation. Different modeling approaches are applied, compared and evaluated, such as the application of a homogenized core layer in connection with a 3D finite element model of the cover layers, or the application of a discrete modeling of the core layer (honeycomb, foam) with shell type finite elements, where the cover layers are again modeled with 3D finite elements, etc. The objective of the project is to develop an effective modeling approach which can be used to design SHM systems for sandwich types of structure with different core materials.