How are innovations in composites contributing to the sustainability efforts of academia and industry?
Composite materials have become more and more integrated into various application industries, from aerospace and transport to architecture and renewable energy. Today, composites offer engineers a solution for a broad range of applications. With new bonding techniques enabling the combination of metals and composite materials, new opportunities have emerged for engineers to choose exactly the right material for the right use. Composites are often praised for their exceptional lightness in comparison with other materials like metals, and can also offer better performance in terms of strength-to-weight ratio.
All of these factors paint a pretty picture when it comes to sustainability, believes Sadik Omairey, Senior Research Fellow and Project Manager at Brunel Composites Centre. Speaking at Advanced Engineering in November, he said: “Net Zero is our destination. Composites, with their high strength-to-weight ratio, prove very useful when it comes to lightweighting applications, particularly in aerospace and automotive. They also have good corrosion resistance, and you can alter their properties to suit what you want to achieve with a particular application. I mention industries like automotive, aerospace, energy and construction as they heavily contribute to greenhouse gas emissions. The more we use composites to produce lighter, more efficient parts for these industries, the closer we get to Net Zero sustainability.”
In addition to lightweighting, composites can also contribute to more sustainable parts and manufacturing processes in several other ways. “Composites can help to reduce manufacturing footprint, they have far less of an environmental impact than metallics, for example, and with lighter parts your final product is going to be less intensive and impactful on the environment,” Omairey continued. “When we’re talking about aerospace and automotive, structures must be durable. Metals can corrode, whereas due to their composition, composites last far longer and can be used across different projects and applications. In terms of applications, they enable structures that wouldn’t have been possible before, such as the size of blades used in renewable energy applications. Finally, they can be recycled and dealt with in a sustainable manner at end of life.”
Based in Uxbridge, the Brunel Composites Centre sits between the knowledge base of academia and industry. The centre aims to transfer academic research in novel composites processing and joining technologies into real-world, industrial applications. To this end, it is currently involved in several innovative projects in the aerospace and maritime sectors.
THE SEER PROJECT
The SEER project focuses on the development of a ‘smart’ self-monitoring tool for aerospace composite manufacturing using silicon photonic multi-sensors embedded using through-thickness reinforcement techniques. The composite tooling will be capable of measuring temperature, pressure and refractive index – directly correlated with the state of the material – to provide a real-time process control with unprecedented reliability.
The performance advantages offered by composites over traditional materials, in particular lightweight, high strength and high stiffness, makes them ideal materials for applications requiring highly advanced technologies, such as aircraft and automotive parts. To meet this increased demand, the team is focusing on two aspects: efficient and controlled curing cycles to reduce costs and speed up production, and the adoption of composite tools for their ease of movement, ease of construction, and lower price, compared to standard metal tools.
THE TAPACO PROJECT
Intake acoustic liners encase large turbofan aircraft engines and attenuate their noise, helping to abate concerns of noise pollution from air traffic. However, lightweighting acoustic liners is a major challenge. The liners are made up of a sandwich structure with a perforated facing sheet and specially designed cell structure that determines acoustic behaviour. State-of-the-art liners are mainly made of thermoset composites with the perforation completed by orbital drilling or robotic laser heads, however this involves cutting the load-bearing fibres which reduces composite efficiency and forces the designer to add more material to the design.
The TAPACO project will address this challenge by using Brunel’s self-developed Thermally Assisted Piercing (TAP) technique to perforate the acoustic liners on the jet engine without the need for drilling. In this technique, the thermoplastic composite material is heated which allows the movement of fibres in the molten mix. The TAP rig can then be pressed onto the composite material in order to displace the load-bearing fibres and create a hole pattern according to acoustic design specifications. The technology is expected to eliminate the main disadvantage of current perforation methods while delivering a cost reduction of between 15-20% due to removing the need for shaping or drilling.
THE COPROPEL PROJECT
Marine propellers have traditionally been manufactured from expensive nickel-aluminium-bronze (NAB) or manganese-aluminium-bronze (MAB) alloys in order to operate under high cyclic loading underwater. However, these propellers require precision machining, long production times and are very heavy to transport. Brunel’s CoPropel project puts forth a holistic approach by introducing a composite marine propeller offering corrosion resistance, lightweight, tailoring of material properties, low electric signature and acoustic properties.
The project is expected to deliver technical achievements and business opportunities for maritime stakeholders which will result in a myriad of social-economic impacts, including: overcoming the limitations of composite materials in maritime, generating a new EU regulatory framework to build complex marine propulsion components in composite materials, enabling advances in composite-based vessel design and production, and enhancing the competitiveness of the European shipbuilding industry.