Unmanned Systems Technology 018 | CES show report | ASV Global C-Cat 3 USV | Test centres | UUVs insight | Limbach L 275 EF | Lidar systems | Heliceo DroneBox | Composites

84 O ver the past several years, the world of unmanned vehicle manufacturers has come to see a dominance of composite materials designed into the structures of hulls, subsystems and components. Understanding why is easy: a material made from two or more constituents with markedly different mechanical or chemical properties can be designed to take advantage of the best qualities of each constituent material. This translates most commonly into materials with very high ratios of strength and stiffness to weight and density, at orders of magnitude far greater than for metals and other bulk materials. This has led to an enormous growth in the diversity of materials choices and combinations. Also, as unmanned vehicles become designed increasingly for more specialised applications, so composites are being produced with better and more precise properties to fulfil their intended applications on those vehicles. That may range from primary load- bearing structural components to lighter hull ‘films’ or heavier parts to withstand the heat from propulsion and exhaust systems. The more extreme the application – such as high-altitude ‘pseudo-satellite’ systems or jet-powered UAVs – the more innovative the designers must be when searching for unique composites to suit their needs. Unmanned vehicles for use in space, at sea, and even on land, gain major benefits when ‘multi- role’ composites are used in place of traditional metals or plastics. Materials options In essence, a composite will consist of a matrix substance, to enclose, protect, bind and support the other component; this ‘other’ will be a reinforcement material, selected to bestow specific properties onto the matrix material. The matrix also transfers loads to the reinforcement through shear loading at the interface. The reinforcement material will most Rory Jackson explains how composites are made and why they are particularly useful for unmanned vehicles Winning combinations February/March 2018 | Unmanned Systems Technology