The UK Net Zero Strategy published in October 2021 reflects the urgency of action needed to avoid climate catastrophe. The net zero journey outlined therein addresses economy and emissions reduction in all sectors, with the specific challenge in aviation a notable element. Global aviation is currently responsible for 2% of emissions with 90% currently from aircraft operations, and this will grow progressively as air transportation grows. In response to this technology and policy are changing rapidly offering both opportunity and challenge, but the standard design systems and processes in practice today are insufficiently agile to support the current need for novel designs that can adapt to these rapidly changing future needs. With current approaches solutions get locked in early based on the available technology level, and optimised around that technology, and consequently have limited opportunity for upgrade and enhancement through operational life, which in the case of aerospace is decades. But delivery of net zero demands radical change quickly. Agile and adaptable design systems are needed to help develop solutions that can be easily upgraded to use advanced technology as it emerges. The key here is that constraints are needed to to allow a baseline solution to be found, but in then optimising around this baseline the constraints become a barrier to future enhancements. To allow future variation without redesign needs new capability. In particular capability to map and measure a design space and to subsequently be able to dynamically change the constraints was found to be a core need for progress in this area. The mapping and measurement capability is needed to understand how constraints are influencing the design at this point in time, and the capability to deal with changing constraints to allow understanding of how the design could change with new technology advance or policy changes. The four research questions emerging from this are therefore: 1. Navigation of Dynamic Design Spaces: How can constraints be represented in a design model such that a changing design space can be navigated and the constraints driving or limiting the design can be identified, and their influence on the design quantified? 2. Evolving Constraints over time: How can constraints be allowed to evolve over time and their influence on the design solutions over time captured, including ability to prioritise requirements/constraints? 3. Measurement and Evaluation of Solution Paths: What metrics are appropriate for maintaining a set of time-history linked solutions open to further development? 4. Keeping Design Options Open: How can design options be kept open, and how can technology changes/policy changes or removal over a long time period be studied? In DECIDE for Net Zero constraints will be permitted to evolve just as every part of the design can. In doing this the design context itself will evolve, creating new fitness landscapes for product evolution. Contrary to standard practice today which is to optimise as far as possible, the aim here is to generate a diverse population of solutions that will have many individuals that survive major disruptions even if some may fail. This is moving significantly beyond current concepts of robust design. This variation of constraints requires a completely novel design system architecture using time history dependent genetics. Geometric analogies for design spaces will allow innovative design tools to support exploration of design spaces in a more meaningful way and the latest bio-inspired methodologies will allow exploration of how products evolve in the context of ever-changing constraints. With this capability robust baseline designs can be developed that will enable the fastest transition to net zero, for example a more modular airframe that can accept plug and play solutions for hydrogen or electric propulsion systems and energy supply which are easy to cost effective to maintain.

Composite materials have seen significant growth in structural applications across multiple sectors due to the high strength and low weight, enabling fuel savings. This is considered a vital component on the journey to achieving Net Zero targets set by industry and governments. To achieve this goal, development of new composite materials is required to see greater adoption of composites to structures. A key area that offers potential for significant weight saving is complex loaded structural joints such as lugs that are used to connect structural components and transfer loads. One of the primary weaknesses facing traditional laminated composites in their attempt to replace metallics in this area is the lack of through thickness reinforcement, leading to delamination and premature failure. 3D woven composites offer a desirable answer to these challenges through use of fibre in the primary xyz direction, with the "z" or binder fibre being able to carry load through the thickness and resist impact damage. Additional benefits for 3D weaving are the ability to create near net shape preforms and tailored properties. Despite the high potential benefits of 3D preforms, there are several challenges associated with it. The first is driven from the high bespoke nature of the material that creates several unknowns in how changes in the 3D architecture or weave parameters will affect the resulting composite properties. This has led to most 3D composites being manufactured in a uniform architecture and not utilising the full potential of the material. The second challenge is the absence of +/-45o or off-axis fibre that is necessary for complex loading conditions. This project aims to address this challenge through developing a new 3D+ material, by utilising the advantages of both technologies through the combination of 3D woven and 2D fibre preforming. The material will consist of a 3D woven core overlaid above and below with off-axis 2D fibre, creating a material that contains both through-thickness reinforcement and off-axis fibres necessary for complex loaded components. The 3D core will investigate the use of architecture transitions within the preform from an architecture tailored to maximise mechanical performance in the main lug body to an architecture tailored for high bearing response and delamination resistance around the lug hole. By utilising existing technologies, a high rate of production is possible with a reduced need for capital investment providing possible rapid and high impact solution for industry. This approach in material design goes against conventional methods of having a homogenised lay-up but generates a potential step change in composite design, a deeper understanding of 3D material, and potential application of composites to structures that have previously been inhibited by traditional lay-ups.

Currently the dominant approach for cooling and lubricating machining processes, such as drilling, milling and turning, is to use emulsion-based coolants (otherwise known as metalworking fluids) at high flow rates. There are many serious environmental, financial and health and safety reasons for reducing industry's reliance on emulsion coolants - an estimated 320,000 tonnes/year in the EU alone, up to 17% of total production costs, and over 1 million people are exposed regularly to the injurious effects of its additives which can cause skin irritation and even cancers. Serious environmental problems are also caused by the up to 30% of coolant that is lost in leaks and cleaning processes and which eventually ends up polluting rivers. These issues have motivated extensive research efforts to identify more sustainable machining processes. There is growing and compelling evidence from preliminary studies that cryogenic machining with supercritical CO2 (scCO2) with small amounts of lubricant (Minimum Quantity Lubrication, MQL, referred to as scCO2+MQL machining) can provide a high-performing and more sustainable alternative. Current knowledge gaps in the relationships between key input and output variables, the reasons for variations in performance and concerns over the release of CO2, are preventing a major uptake of this technology by UK manufacturers. This project aims to test the hypothesis that optimising combinations of CO2 with small amounts of the appropriate lubricant can provide reliable, step-change improvements in the performance and sustainability of machining operations. It will carry out a systematic investigation into the effect of scCO2+MQL on cutting forces, heat and tool wear mechanisms during machining of titanium, steels and composite stacks. It will develop: (a) advanced experimental methods in combination with full-scale machining trials to explore how lubrication and heat transfer affect machining performance; (b) lifecycle assessment and scavenging methods for sustainable re-use of CO2; (c) machine learning methods to predict the relationships between process inputs and outputs and (d) develop an effective and efficient optimisation methodology for balancing competing financial, performance and sustainability objectives in scCO2+MQL machining. These will deliver the knowledge, experimental and modelling methods and software tools that UK industry needs to exploit this enormous as-yet untapped potential. The project will involves staff and postdoctoral research assistants from the Universities of Leeds and Sheffield and the Advanced Manufacturing Research Centres in Sheffield, with advice and guidance from a Project Steering Group comprised of leading international academic and industrial experts. Collectively, the team has the expertise in (a) manufacturing systems and tribology; (b) energy systems and lifecycle assessment; (c) fluid mechanics and heat transfer, and (d) machine learning and optimisation, needed to provide the 'how' and 'why' UK industry needs to reliably achieve or exceed the performance improvements seen in preliminary studies, namely doubling of tool life. We will work with our industrial and business sector collaborators to drive transformations in machining rate, process cost and accompanying safety, environmental and quality metrics for the benefit of the UK's defence, civil nuclear and medical manufacturing industries through the 2020s and beyond.

High value manufacturing is an essential component of the UK economy, contributing strongly to our economic prosperity and engineering status around the world. The growth in high value manufacturing to support aerospace, nuclear and other high integrity engineering components, has placed huge pressure on the rapid delivery of reliable and high quality Non-Destructive Evaluation (NDE) to inspect these parts. Currently, much inspection of safety critical components (sometimes requiring 100% part inspection) is performed manually, leading to significant bottlenecks associated with the NDE. Existing robots typically follow pre-programmed paths making them unsuitable to handle, inspect and disassemble parts with a significant tolerance or variability. A new end-to-end approach is needed, embracing manufacture, transport through factory, parts alignment, parts tracking, and inspection (both surface form metrology and NDE) with the associated high volume data management feeding into the quality and assurance compliance processes. Exactly the same process bottlenecks occur when we translate the problem to the regime of Remanufacturing, hence the integrated approach taken through this proposal. Remanufacturing has been identified as being central to the creation of economic growth in the UK and global markets. With supplies of resources and energy limited, the transition to a low carbon economy with strong emphasis on resource efficiency is key to the UK's Industrial Strategy. Remanufacturing can support this transition by achieving significant impact in all industrial sectors through preventing waste, improving resource management, generating sustainable economic growth, increasing productivity and enhancing competitiveness. AIMaReM (Autonomous Inspection in Manufacturing& Remanufacturing) provides a unique combination of data collection, processing and visualisation tools combined with efficient robot path planning and obstacle avoidance, with a focus on manufacturing inspection (NDE and surface form metrology). The project will deliver an automated, systems integrated solution, that will be of direct benefit to the manufacturing sector to allow faster integrated inspection and parts handling, thus saving time, and reducing costs whilst enhancing quality and throughput.

This CDT will train the next generation of manufacturing researchers with unique capabilities to combine predictive models and in-process data, with a systems perspective, to enable faster, more flexible, and more sustainable high value manufacturing. The UK's growth lags behind Europe and North America [1], and the chancellor, whilst celebrating our advanced manufacturing sector, also states [2] that 'poor productivity, skills gaps, low business investment and the over-concentration of wealth in the South-East have led to uneven and lower growth'. Although digital technologies are recognised [3] as a key productivity enabler, integrating these into an advanced manufacturing environment is a significant challenge. Our CDT will address this from a systems perspective by using sensors, communications, controls and informatics technologies that are coupled to the physics underpinning complex manufacturing processes. This vision aligns strongly with the EPSRC's priorities (especially AI Digitalisation and Data); the EPSRC Made Smarter programmes, and the UK Innovation Strategy's [4] digital and manufacturing priorities. However, embedding Digital Manufacturing into the UK economy will require people with new doctoral-level skill sets dedicated to the four productivity challenges in manufacturing: 1. sustainability - an emerging underpinning theme in our stakeholder discussions. 2. speed - reducing production lead time; 3. quality - eliminating rework whilst achieving functional performance; 4. flexibility - adaptive production systems that eliminate intrusive setup/measurement; The CDT will train cohorts that focus on cross-disciplinary research at the interface between these productivity challenges and key Digital Engineering themes identified by our industrial co-creators: (1) mechanics, modelling, and intelligent control / optimisation of processes; (2) sensor networks and monitoring; (3) manufacturing informatics, system integration, and data security. We will focus on key manufacturing processes that are essential to the UK landscape: subtractive manufacturing (machining) and product assembly. We are uniquely placed to enable this approach: we lead the machining capability on behalf of the High Value Manufacturing Catapult, collaborate on the Manufacturing Made Smarter Research Centre in Connected Factories, (with a focus on assembly automation), and through Factory 2050 we host the UK's first state of the art factory entirely dedicated to reconfigurable robotic, digitally assisted assembly and machining technologies. We will provide a unique opportunity for students to study alongside peers with a common application focus in machining, assembly, and digital engineering for manufacturing, leveraging the world leading environment provided by the Advanced Manufacturing Research Centre. This will enable the highest standards of subject-specific research training, underpinned by Sheffield's breadth of activity in engineering science. We will tailor the first year training to support their transition into the centre, and provide cohort experiences that reinforce system-level thinking and leadership skills, to ensure that our alumni's impact on society far exceeds that of a typical PhD student. Training will be undertaken individually, within a cohort, across the centre, and in combination with other centres and groups. Through this approach, we will achieve horizontal and vertical integration of the student experience within the centre and will support students in developing the specific skills required for their research. This will foster a collective culture in key training areas such as leadership, inclusion, innovation and communication, amply preparing students for their future careers. [1] IMF, World Economic Outlook Jan 2023 [2] Chancellor Jeremy Hunt's speech at Bloomberg, 27/1/2023 [3] RAEng/IET Connecting Data Report 2015 [4] UK Innovation Strategy: Leading the future by creating it