Composites: Ready for take-off

A new partnership has been formed to develop revolutionary all-composite helicopter wheels in the UK.

Carbon ThreeSixty, the advanced composite structure specialist, is leading a new project co-funded by Innovate UK, the UK’s innovation agency, to develop a revolutionary all composite helicopter wheel.

The project started on the 1st of January and will run for the next 18 months. The National Aerospace Technology and Exploitation Programme (NATEP) project is being delivered in partnership with the National Composites Centre, collaborating with Leonardo and ultimately aims to improve performance, safety & full ownership cost.

NATEP assists companies in the aerospace supply chain to work collaboratively in the development of innovative technologies through a unique combination of match funding, mentoring and end user support. Participation in the programme equips project partners to win new business with existing customers and to diversify their customer base. Since 2013 the programme has brought together technology collaborations of more than 350 aerospace supply chain micro, small and medium sized companies.

The technologies developed within the NATEP Programme will be used on current and new aircraft programmes, increasing productivity, creating jobs and injecting new R&D capabilities into the supply chain. NATEP companies are supported to be better able to win work with existing customers and new customers, particularly in export markets, as well as in cross sectors markets such as the automotive, energy or rail sectors.

The aim is to leverage the consortium’s combined expertise to design, develop and manufacture an ultra-low mass, robust, proof-of-concept carbon fibre reinforced plastic (CFRP) wheel for rotary wing aircraft.

The current global market for helicopter wheels uses metallic light-alloy materials, usually aluminium or magnesium. These offer sufficient strength and stiffness from a relatively low density.

A wheel made of CFRP will offer significantly enhanced mechanical properties at approximately half the density of metallic wheels. Compared to aluminium alloys, a CFRP wheel will be lighter, with higher performance with an extended working life.

Existing light metal alloy helicopter wheels can suffer from undesirable fatigue failures and have to endure relatively harsh environments. This requires regular preventative and corrective maintenance throughout the life of the aircraft.

The fibrous microstructure and resin stability of advanced composites mean that fatigue life and corrosion resistance can be much improved when optimally designed. They also offer weight savings of around 30-40% over forged aluminium and improved NVH (noise, vibration and harshness) performance.

Weight reductions enable airframers to deliver efficiency, range and payload improvements and provide an option for lower power density propulsion systems, such as battery-electric. Composite wheels will also be interchangeable with existing wheels, making them suitable for retrofit applications.

Carbon ThreeSixty provide light-weighting solutions using advanced composite materials and manufacturing processes. They specialise in resin transfer moulding (RTM) and novel preforming techniques such as tailored fibre placement (TFP) to produce highly optimised and cost-effective structures.

The business has delivered several innovative light-weighting products into automotive and defence sectors including Heavy Duty Vehicle run-flat structures, next-gen tracked vehicle road wheels, and all-composite wheels for land defence vehicles.

Ed Allnutt, Managing Director of Carbon ThreeSixty said: “The application of advanced composite materials and processes specifically to aerospace wheels is a highly innovative step.

“Our experience with other composite wheel applications has shown that weight savings of 30 to 40% are achievable over forged aluminium solutions.We believe the key selling point, however, will be the improvements in fatigue life and failure mode which will extend life and improve safety.

The project will use cutting edge composite manufacturing technology such as tailored fibre placement (TFP), braiding and out of autoclave processes to ensure repeatability and scalability while utilising novel product and process design to enable the partners to protect IP required to successfully manufacture the products.

One of the partners is the National Composites Centre is a world-class research centre, where companies of any size and across industry sectors, can access cutting-edge technology and specialist engineers, to drive innovation in the design and manufacture of composites.

Alex Doyle, Technology Project Lead of National Composites Centre said: “Composite wheels have only become viable in the last 10 years due to improvements in resin system toughness, lower carbon fibre prices and improvements in process automation. We can see this in the automotive wheel market, where they are now proven.

“However, aerospace applications are more challenging. The shift in cost, combined with the technical improvements are the reason why now is the time composite wheels are feasible for aerospace rotorcraft applications.”

The scope of the project covers the specification, design, development, manufacture, inspection and testing of a proof of concept helicopter wheel, considering full aerospace requirements in line with the specification provided by Leonardo for an undisclosed platform.