Issue 41 Unmanned Systems Technology December/January 2022 PteroDynamics X-P4 l Sense & avoid l 4Front Robotics Cricket l Autonomous transport l NWFC-1500 fuel cell l DroneX report l OceanScout I Composites I DSEI 2021 report

82 I ncreasingly, unmanned vehicle manufacturers tend to specialise across disciplines in avionics, power management, AI or systems integration. As discussed in our cover article (page 22), composite materials tend not to fall within the focus of such companies’ r&d, and with good reason. The materials, which combine the latest matrix and reinforcement substances in varying permutations, represent the pinnacle of commercially available solutions for strength and lightness, not only for vehicle bodies and chassis but many other parts, including gimbal housings, structural supports and electronics enclosures. The advantages they give in weight- saving, durability and lifetime over standard metals and plastics are prized not only among aircraft and automotive groups but also in the space, marine and motorsport markets, among others. This widespread and persistent demand drives composite materials companies to continually experiment with their materials and processes to push the boundaries of what they are capable of producing. The result is that the past few years have seen major advances in key features of composites, which unmanned systems engineers should be aware of in order to push their vehicles’ endurances, carrying capacities and reliability levels beyond those of their competitors. Materials Many essential material inputs for composites are well-established and known among unmanned vehicle engineers. Briefly, the most common are typically fabric or glass, carbon or aramid fibres, distributed as rolls or sheets either pre-impregnated with resin (‘pre-preg’) but not yet cured, or stored dry to be wetted with resin (in a ‘wet layup’), typically by hand, also to be cured afterwards. The fibres themselves can be further categorised in terms of their orientation within the fabric. The most basic is unidirectional fabric, where the fibres are laid in a single direction of orientation (thus giving optimal mechanical properties in that single dimension but not the others). Where greater dimensional stability is needed, bidirectional materials are available, and some more advanced fabrics are described as quasi-isotropic – that is, having the same mechanical properties in all planar directions. If sufficient thickness is designed Rory Jackson explains how composites suppliers are improving their materials to meet the growing needs of unmanned systems developers Material gains December/January 2022 | Unmanned Systems Technology Designing for manufacture is a critical service provided by experienced composites suppliers to UAV developers (Courtesy of Norco Composites)