Optimal design of triaxial weave fabric composites for specific strength and stiffness under tension

Triaxial weave fabric (TWF) composites are increasingly used in ultralight flexible structures, such as deployable antenna on spacecraft and wing skins of unmanned aerial vehicles (UAVs). High specific strength to stiffness ratios are important to avoid damage under large deflections and during folding and unfolding, whilst ensuring that they remain light weight. Genetic Algorithms (GAs) are widely used in the composite optimisation literature to find weaves that give optimal properties. Previously MLSGANSGAII and NSGA-II were shown to have the best performance in finding optimal schema for triaxial weave fabric composites and are used to generate Pareto Fronts of stiffness and strength. In this study the density of the material is also considered. 500 Pareto front points are achieved with 15 designs that are potentially capable of being designed for ultralight structures. A potential increase of 228.05% in the strength to stiffness ratio with increase of 149.49% in the strength is made with the same surface density as a current example. These allow selection of designs with high specific strength to stiffness ratios, ensuring practical designs that can be used for ultra-lightweight applications.