Additive manufactured sandwich structures: Mechanical characterization and usage potential in small aircraft

The developments in manufacturing technologies, in particular through the establishment of additive manufacturing (AM) processes, offer new possibilities in sandwich design. With the use of AM it is possible to build a full metallic sandwich plate without the need of adhesive connections. This results in a more reliable bond. In this paper, AM metallic sandwich structures with pyramidal cores and their application as load carrying members in small aircraft are investigated. For this, analytical and numerical models describing the sandwich properties are first derived and then experimentally validated. The tested specimens are produced from AlSi10Mg using Laser Powder Bed Fusion (LPBF). These models are then used to derive equations which are needed to implement a homogenized element for numerical calculations. Afterwards the element is used to analyze and optimize a small aircraft wing. At last, the resulting wing is compared to an equivalent wing using a conventional structure. It is shown that compared to conventional structures, high weight savings can be reached by using AM sandwich structures, but also that with AlSi10Mg no sufficient qualities can be reached to obtain the needed structural performance.