Flexible Skin Development for Morphing Aircraft Applications via Topology Optimization

This article describes the development of engineered composite skins for morphing aircraft applications. Some of these applications suggest that materials with low in-plane stiffness and relatively high out-of-plane stiffness may be required. To this end, a two-step design process has been developed in order to synthesize skins to meet these requirements. The first step in the process is to determine bulk material properties for the skin and the layout of attachments between the skin and underlying substructure. This results in a distribution of bulk properties across the skin. The second step utilizes these property values as constraints to match the found bulk property in a multi-phase material optimization in order to determine the layout of a set of microscopic multi-phase material unit cells. As a first attempt, a 2D engineered skin design using a proposed two-step process is demonstrated in this article, and material fabrication process using a rapid prototyping (RP) technique and test result are discussed.