Transport is responsible for around a quarter of the UK's total greenhouse gas emissions. Light-weight recyclable materials, such as thermoplastic composites, are recognised as a sustainable solution to reducing transport emissions via "light-weighting". Thermoplastic composites have several advantages over their thermosetting polymer composite cousins, including faster processing, improved recyclability and increased toughness, though they are more challenging to process which partly explains their smaller market share (~1/3rd that of thermosets). Consequently, there is an urgent need to address the manufacturing issues to realise their full weight and fuel saving potential. However, forming advanced thermoplastic composites into complex geometries is not always straightforward and production defects such as wrinkling, bridging and tearing of the forming sheet are commonplace.The main idea of the project is to develop a novel sheet forming process for advanced thermoplastic composites designed to mitigate manufacturing defects when thermoforming multi-axial laminates into complex geometries. This will be achieved through the creation of wrinkle-resistant 'lubricated-blanks' using a combination of induction heating and a novel incremental forming process. Typically, to achieve optimum mechanical properties in composites structures, placement of fibres in multiple directions is required to accommodate complex loading conditions. However, despite the development of sheet forming processes for advanced composites dating back over 30 years, questions regarding production defects have yet to be satisfactorily answered, namely: 'How to form complex components from pre-consolidated multi-axial thermoplastic laminates without inducing wrinkles?' and 'How to form highly complex geometries involving multiple recesses, without bridging or tearing of the forming laminate?' The proposed research combines two distinct new ideas. The first is to create a 'lubricated blank', using induction heating and melting of metallic inter-layers placed within the forming composite sheet to facilitate ultra-low inter-ply sliding friction and consequently, wrinkle-free forming of multi-axial pre-consolidated advanced thermoplastic composites. The electromagnetic properties of certain metals coupled with their high surface tension and low viscosity when molten mean they can be used as a medium with which to both inductively heat and lubricate the forming composite blank, thereby preventing wrinkles. The second idea is to use a multi-step forming tool designed to create an automatic sequential and incremental forming process in a single press-forming down stroke, beginning at the centre and subsequently moving outwards towards the perimeter of the sheet. The multi-step forming tool serves to both mitigate bridging and tearing and crucially, squeezes the molten metal out of the composite layup (like squeezing toothpaste from a tube!) and into the surrounding rubber diaphragm during the thermoforming process, leaving the final consolidated composite part almost completely free of embedded metallic inclusions.

The rapid growth of computing power during the last 50 years has given rise to a whole simulation industry serving the needs of the manufacturers looking to design products in an optimal manner, without the time and costs associated with building a series of physical prototypes. Design and construction decisions are increasingly made by means of virtual prototyping as part of Computer Aided Engineering (CAE), and efficient simulation tools in all areas of engineering are sought after. Noise and vibration are particularly important performance aspects in the design of many mechanical systems. High noise and vibration levels can be damaging to structures and to their users (potentially causing hearing loss, for example). Developing computational techniques to improve our understanding of the vibration and acoustics of complex built-up structures can enhance performance, speed up the design cycle and ultimately result in safer and less noisy products. Methodologies have long been sought after for modelling large-scale complex structures such as aircraft, trains and cars. The sheer size of these structures makes building full-scale physical prototypes expensive, and often infeasible. It also poses problems for simulation methods and limits many CAE products to low frequencies, where computational run times are relatively low and uncertainties have little influence on the vibrational behaviour. Uncertainties arising during the manufacturing process (for example, in material properties or physical dimensions) can lead to large variations in the levels of noise and vibration of a structure at high frequencies, and so mechanical engineers have turned to statistical methods to instead predict averages of these noise and vibration levels. Unfortunately, these statistical methods are based on a set of assumptions that are hard to control and generally only fulfilled for more traditional structural designs. They are not fulfilled for the large curved and moulded components used today. Therefore the CAE tools available at present for simulating mid- and high- frequency noise and vibration do not meet the needs of engineers in the transport sector. As a result of the 2008 climate change act in the UK and similar initiatives around the globe, transport industries are undergoing a period of great change. Alternative fuel sources and lightweight materials are two of the major areas of development. An increasing number of hybrid and electric powered vehicles are appearing on the market and the use of lightweight and composite materials is increasing across the sector. Engineers were already in need of new and more versatile simulation methods at mid-to-high frequencies, but the increasing popularity of lightweight materials and electric power sources has compounded this situation for three main reasons: - only estimates of the material properties for newly manufactured lightweight and composite materials are available introducing considerable uncertainty into the model; - lightweight and composite materials typically emit noise at higher frequencies than more traditional steel or aluminium based structures; - sources of noise and vibration (eg. electric motors, air resistance etc.) will mostly be at high frequencies. In this proposal, random (or stochastic) transfer operator methods will be developed for modelling mid-to-high frequency structural vibrations in large complex structures. These methods will have the advantages of the current statistical approaches in terms of being able to model uncertainties in the structural design and materials, but crucially will be applicable to a far wider range of structures, including large moulded components and novel lightweight materials. The approach to be developed therefore has the potential to provide a black-box design tool for mechanical engineers looking to develop the next generation of green and lightweight transport structures.

Mechanical metamaterials are materials that are specially designed to have unprecedented mechanical properties and multi-physics characteristics beyond those of classical natural materials. The properties of mechanical metamaterials are defined by their topology and geometrical architecture, and the characteristics of the materials which they are made from. Changing any of these directly affects the structural response and allows us to explore new areas in the material property space. Interesting properties that metamaterials exhibit include zero and negative Poisson's ratio leading to unexpected behaviour when subjected to mechanical stresses and strains, zero and negative stiffness, ability to absorb/dissipate energy and ability to isolate vibration. These properties give metamaterials high industrial value as illustrated by the global metamaterials market, valued at $1.5 billion in 2022 and forecast to grow to $22.9 billion by 2028. The focus of I5M is Mechanical Constant-Force MetaMaterials (CFMMs). These can deliver a quasi-constant output force over a range of input displacements (i.e., they can apply a constant pressure on a surface or object). This means they can act as passive force regulation and vibration isolation devices without any need for sensors and complex electromechanical control systems and have potential to be used in many applications such as robotic automation, overload protection, and precision manipulation. Despite recent advances in materials and manufacturing, CFMM development suffers drawbacks such as limited material selection and working range, unrealistic theoretical assumptions, high computational cost, need for assembly, material waste, and ignored fatigue performance. These drawbacks mean that a huge portion of the CFMM design space remains untouched. To address these challenges, a methodologic breakthrough is required that seamlessly integrates the four pillars of CFMM development: material, modelling, design, and manufacturing. Hyper-ThermoVisco-Pseudoelastic (HTVP) materials like Thermoplastic Polyurethane (TPU) have a nonlinear stress-strain behaviour and possess an inherent energy dissipation capability with excellent toughness and cyclic fatigue resistance. Employing the inherent energy dissipation feature of HTVP materials and unique behaviour of CFMMs along with advances in 3D printing can realise CFMMs with tailorable static and dynamic properties and open a vast design space meeting desired characteristics. This project aims to exploit inherent energy dissipation features of HTVP materials and develop an Integrated Material-Modelling-Manufacturing paradigm to create a new class of Mechanical metamaterials so-called Meta-regulators (i.e., I5M) with minimal computational cost, material usage and expert interference. I5M will break new ground by creating and exploiting breakthroughs in HTVP materials with variable soft-to-stiff properties, triaxial normal-shear constitutive modelling, physics-informed machine learning for evolutionary inverse design, and sustainable 3D printing. I5M technology will represent a fundamentally new field of sustainable metamaterials paradigm and create passive HTVP meta-regulators with built-in functionalities such as with programmable quasi-zero stiffness, quasi-constant force regulation, tuneable vibration isolation and fatigue resistance. I5M will minimise the expert interference, for example, I5M will simply receive constant force-displacement response and vibration transmissibility as input, determine optimum material and geometrical parameters, and then 3D print a meta-regulator meeting those requirements. I5M will validate HTVP meta-regulators functionality via 4 demonstrators for healthcare, automotive, aerospace and sport industries.

There is an increasing demand across engineering sectors for advanced materials, many of which are incompatible with current manufacturing processes due to their sensitivity with heat, impact and abrasion (e.g. composites, metallic glass and intermetallics). The economic machining of these materials is essential to exploit their enhanced properties and overcome some of the 21st century's challenges, including the development of efficient zero-emissions transportation. Transportation is the largest contributor of greenhouse gas (GHG) emissions in the UK, accounting for 28% of the total. The UK Government's Transport Decarbonisation Plan aims to achieve net-zero GHG emissions by 2050, with a staged introduction from 2030. Comprehensive use of advanced composites in the structure and propulsion systems of aerospace and automotive vehicles will result in significant GHG emissions reduction. Currently, however, the lack of cost-effective and reliable manufacturing processes is limiting the pace of adoption in the aerospace and automotive industry. This fellowship aims to develop and demonstrate next-generation laser-based manufacturing technology that will enable advanced composites to become effective solutions for application and adoption across multiple sectors. The goal will be achieved by transforming two emerging laser-based technologies into fully-fledged industrial solutions, underpinning the large scale industrialisation of advanced composite solutions. The first of these technologies is the water-jet guided laser (WJGL); initial work performed at the MTC has proven its capability on composite cutting. However, the current generation of WJGL technology, developed for low power nanosecond lasers, is not suitable for the mass production industrial environment. To overcome this issue, this fellowship will develop a novel high-power WJGL system with a 2kW microsecond laser for cutting and drilling of composite materials, offering a 10x increase in productivity whilst maintaining component quality. Ultra-short pulse laser (USPL) can ablate any material by cold ablation. While this extraordinary capability has been proven using low power USPL for a limited number of niche applications, its low material removal rate and its drawback of edge wall taper are currently limiting its viability in the wider manufacturing sector. To address the power limitations, the MTC together with its partners, are developing high-energy USPL with an average power of 2kW. The challenge now is to exploit the kilowatt range USPL without losing its cold ablation capability. This fellowship will develop a novel beam scanner that will facilitate stable filament-based USPL beam propagation and ultra-high-speed beam manipulation which will enable the exploitation of kilowatt range USPL for cold ablation-based machining of composites with enhanced processing rate capabilities and without edge wall taper. Working closely with strategically vital high-value manufacturing industries, universities and the HVM Catapult centre, my fellowship aims to transform the laser-based manufacturing, manufacturability of composites, and accelerate their economic exploitation in industries, through the following: 1. Technical development: Development of novel laser-based technologies for high-volume throughput and high-quality manufacturing of composites. 2. Scientific investigation: Science-based investigations to develop the underpinning knowledge and understanding of laser-based manufacturing. 3. Industrial exploitation: Facilitate the exploitation of the laser-based composite manufacturing within the automotive and aerospace industries (both facing increased financial and environmental challenges) in the near-term and the wider manufacturing sector in the long-term. 4. Resource development: Enriching the skills base, leadership, and infrastructure for a long-term sustainable R&D competency in the UK on next-generation laser-based manufacturing.

The fundamental goal of this proposal is to Re-Imagine Design Engineering so that new ideas and concepts are generated rapidly, and where both the product and its associated manufacturing system (including its supply chain and people) are designed concurrently and fully tailored to each other. By doing this the >70% of lifecycle and supply chain costs that are "locked in" at the concept design stage can be understood, minimised and verified. This programme will target the transformation of Design Engineering via Interoperable Cyber-Physical-Social (CPS) Services in which: (i) engineering competences and multiscale physics are integrated by innovative digital capabilities, (ii) advanced analytics support capture of knowledge, enhance resilience and predict compliance by interoperable 'smart testing' and fully simulated lifecycle analyses to validate model-centric designs, (iii) novel business/supply chain models provide a transparent value stream from digital design through to manufacturing and pathways to ensure the UK develops the next generation of digital engineering talent. Our vision of the future where manufacturing systems are self-organising, self-aware and distributed, brings a radically different manufacturing industry than exists today. This leads naturally to identifying four major research challenges to this programme: 1. Interoperability - CPS Design Theory: How can we generate ideas and concepts rapidly such that artefacts are designed concurrently with manufacturing systems to create resilient extended enterprises with open communication throughout the whole system? 2. The Cyber World - CPS Modelling Design & Manufacture: How can we represent concepts virtually such that key design characteristics driving intended behaviour are understood, coded and realised via robust, intelligently manufactured product variants? 3. The Physical World - CPS Concept to Reality: What verification and validation concepts are needed to find the shortest and most beneficial pathway to physical realisation aided by a cyber-physical-socio manufacturing ecosystem? 4. The Socio World - CPS The Extended Manufacturing Enterprise: How can we translate and exploit concepts in new organisational structures within a cyber-physical-socio ecosystem to accelerate evolution of design solutions across extended enterprises? The four technical challenges are integrated and pose interdependent challenges. They form the four threads which are to be woven together in this programme. A range of approaches for modelling, evaluation and prediction are needed for the whole programme, and dealing with such diverse system entities from simulation models to individual human and business organisations necessitates a diversity of technical approaches. The concept of 'cyber-genes' and 'cyber-seeds' that can be used in an evolutionary approach form the core thread to provide a new CPS design theory but requires significant interlinkage with the other aspects. For example, CAD models in the cyber world are sufficient for some products, but in general systems are multi-functional and multi-disciplinary and will require a range of modelling methods to provide the necessary design evaluation data, such as with whole life costing. Similarly, although possible to communicate with manufacturing (e.g. CNC machines), feedback of intelligent data directly into a live design is not yet done, and new methods are needed in both design systems and the organisation to allow this capability. Overlaying evolutionary algorithms to these will necessarily require all elements to be adapted and changed, as both the system and underlying methods evolve. Therefore, these nature analogous processes and a range of alternative approaches (e.g. fractals, agent-based systems, response surface methodologies etc.) will be explored.