In an insightful interview, composites expert Dr David Hughes discusses the latest trends and how these could translate from academic research to real-world applications
Dr David Hughes is a well-known figure in the world of composites. A Senior Lecturer in Materials Engineering and Enterprise Fellow in Teesside University’s School of Computing, Engineering & Digital Technologies, Hughes has spent many years working in composite design – particularly in digital manufacture for optimised performance and waste reduction.
His passion for the sector arises from the vast potential he sees for composites in industrial applications. “One of the main strengths of composite materials is the huge material and design flexibility,” he begins. “However, this adds huge complexity to design and optimisation. Commonly in industry composite parts are passed between stress analysists, part designers and manufacturing engineers iteratively improving designs based on expertise. These skills are in short supply, which restricts growth in the composites sector.” But Hughes is already looking for solutions to this issue, explaining that, “Digital tools can help bridge those expertise gaps and, because we have joined the Siemens Connected Curriculum, specifically as users of Fibersim for composite design, we can now support training by delivering digital skills across all our engineering degrees.”
These degrees are becoming increasingly popular, reflecting the wider industry trend towards all-things composites. “The application of composite materials into all areas of engineering has grown rapidly since 2008,” Hughes reflects. “The initial focus was on high-value applications such as aerospace and motorsport, due to high material and processing costs. More recently, the opportunity that composite materials present, namely enhanced mechanical properties and flexibility in design compared to other materials, has seen use and interest grow across all sectors.”
Hughes says that a key limiting factor to further growth and adoption has been the high material waste percentages associated with composite manufacturing. “Material waste can commonly range between 5% and 60% depending on the material, part design and process. Material waste percentages are a particular barrier to adoption of mass-produced composite parts,” he states. “A number of key drivers exist for composite waste reduction: currently largely non-renewable material sources; similar embodied energy to metals; difficulty in recycling; barriers to disposal (EU Directive on Landfill of Waste (Directive 99/31/EC)); comparatively high material production costs (carbon fibre reinforced plastic estimated at up to 60% higher than production costs of steel and about 25% higher than aluminium); and material cost often the single largest component in total product cost.”
How to reduce composite parts waste
What can be done to improve the waste situation, then? “As with most industries, digitalisation is playing a significant part in the development of composite design and manufacturing. Lay-up waste is linked to inefficient planning and orientation of composite materials during manufacture,” says Hughes. “To directly address this, manufacture planning must be integrated into the design process. A key design factor is not just function and manufacturability but when considering waste, is the ability to nest (fit the cut-out shapes onto a sheet) efficiently. Through our work at Teesside University we have shown 50% improvements in material use through redesign to optimise sheet use through nesting but we are changing the cut-out shape to achieve that.”
Composites industry trends
Discussing the current industry trends, Hughes says that one hot topic is that of recycling and reuse. “The fibres used in the manufacture of composites contain most of the value and so lots of work is going on not only to divert high value material from landfill but also to recover the fibres in a way they can be reused. Automation in composite manufacture is also growing and displacing more traditional hand lay-up in many sectors. The capital costs have come down on the equipment and the material performance/production efficiency benefits are very high.
“Effective simulation is also a growing field in composites. This is at every scale: molecular to understand bonding, micro to understand fracture mechanics, and macro to understand multi-part, multi-material systems.
“Lightweighting is one of the most interesting areas. It has always been the core use of composites, but a composite is simply a blending of materials and therefore a blending of properties. I am increasingly interested in not just lightweight but the blending of wider properties, for example high temperature or electromagnetic performance that composites can offer. Composite materials are infinitely designable and I am really interested in applications that harness the best from different material properties.”
Composites in the real world
When prompted for examples of how his work is being adopted in real-world applications, Hughes says: “A good example is Stratobooster, whom I have worked with to develop lightweight rocket bodies for the launch of femto (small) satellites. Another example is a project with Core6 supporting the development and testing of composites for the construction sector.” He adds; “There are a number of other projects I am working on but cannot name currently (defence applications, etc.), though I can say generally include high temperature (>800°C) composites for aerospace, geo-polymer composites (that are again high temperature), composite insulation materials and composites for use in rotational moulding.”
Composites end product examples
Hughes can also offer several nice instances of his work being translated into commercial products. “Two really good examples are our Innovate UK-funded Knowledge Transfer Partnerships with Peel Jones Copper Products and Scott Bros. For Peel Jones, we have effectively moved the company from traditional 2D drawings to a fully digitised design and manufacturing processes. Through the project we also captured the customer voice, which showed there is great interest in instrumentation and improving the reliability of tuyeres. This has also opened doors for new business opportunities and commercial exposure for the company. And for Scott Bros, a haulage and plant hire business, we found a practical solution for utilising their own particular brand of unwanted ‘filter cake’ by creating a new geopolymerisation process to apply mineral and soil wastes into cement production, impacting on the circular economy.”
When asked what he’ll be researching next, Hughes says, “I am very interested in improving the sustainability of the composites we are developing. Developing circular business models to support advanced materials is key to their future viability. That is why we are now focusing on geopolymers that are waste derived and chemical methods for recovering and reusing composite plastics.” He adds: “This is supported by my role as Chair of the IOM3 Polymer Group and co-ordinator for our Circular Economy and Recycling Innovation Centre.”
When it comes to the ultimate potential for composites in real-world applications, Hughes is pragmatic; seeing huge (and viable) potential, so long as challenges can be overcome. “I think composites, in the broadest sense, hold the greatest potential for future materials development and optimisation as we can blend and design materials and their properties for specific solutions so effectively. We must overcome the hurdle of mixed material recycling and recovery though to ensure this is a sustainable future.”