Virtual folding core characterisation for the design of complex sandwich structures

Sandwich composite structures are used in a wide range of applications due to their excellent lightweight construction potential and are the subject of research at the Institute of Aircraft Design. The institute primarily develops and researches novel folded core structures that represent a high-performance alternative to commercial sandwich core materials. These folded cores are created from a flat semi-finished product using a folding process and allow for a wide range of materials and cell geometries. The cores also form an open structure that can be used for functional integration. For example, it is possible to integrate cables or sensors, but also to transport media directly for active temperature control of the sandwich structure. In addition to the choice of material, the mechanical properties of folded core sandwich composites depend on the folding geometry. This can be varied almost at will and allows a wide range of designs to be created, adapted to mechanical and functional requirements.

Structural mechanical analyses of the folding cores are performed to map the complex processes under load. This allows for rapid analysis of the mechanical properties and investigation of a large number of different geometries. A model-based optimisation environment facilitates the rapid evaluation of geometries with regard to specific application scenarios. The folding core geometries are now virtually designed, tested and optimised in an automated numerical process chain.