How can experienced professionals find research projects in their niche area?

Many experienced professionals can easily find research projects in their niche area, but young PDRAs and PhD students may not know how to find them. Research projects can offer opportunities for learning, networking, and career advancement. However, finding research projects that match one’s skills and interests can be challenging. For that reason, we will introduce some strategies and resources for finding research projects in your niche area.

  1. Identify your research interests and skills.

Identifying your research interests and skills involves introspection into your academic background, personal passions, and career objectives. Questions like, “What are the primary themes or issues that captivate me?” and “What gaps or challenges exist in my field of study?” can guide this reflection. Additionally, consider the skills or methods you enjoy using or learning, and ponder how you wish to contribute to the progress of knowledge or society.

To pinpoint your research interests and skills, explore diverse sources of information and inspiration. This may include perusing academic journals, books, or websites pertinent to your discipline. Seek input from current or past professors, colleagues, or peers who share your interests. Delve into online databases or platforms listing research opportunities or projects and explore professional associations or networks offering guidance for researchers.

To find meaningful projects, look for titles such as research assistant, research officer, or research specialist in relevant fields. Utilize keywords when searching on platforms like LinkedIn and ResearchGate to discover valuable opportunities.

  1. Explore existing research projects and opportunities.

One of the crucial skills for a researcher is the ability to investigate existing research projects and opportunities. This skill aids in discovering new collaborators, recognizing gaps in the literature, and identifying potential funding sources. Here are some suggestions on how to explore existing research projects and opportunities:

– Utilize online databases and platforms that aggregate research information, such as Google Scholar, ResearchGate, Scopus, and others. Conduct searches based on keywords, topics, authors, institutions, or citations to locate pertinent research papers, projects, and researchers.

– Attend conferences, workshops, seminars, and webinars aligned with your field of interest. Stay informed about the latest developments, trends, and challenges in your research area while networking with fellow researchers who share your interests. Additionally, consider presenting your own work to receive feedback from peers and experts.

– Join professional associations and societies that represent your research domain. Gain access to their publications, newsletters, events, and membership directories. Participate in committees, working groups, or special interest groups to contribute to their activities and initiatives.

– Initiate contact with potential mentors, advisors, or collaborators working on topics or methods that intrigue you. Reach out through email, social media connections, or request a meeting to inquire about their current or past projects, research goals and challenges, and seek advice.

– Explore your institution’s research resources and opportunities. Check your department’s website, bulletin board, newsletter, or email list for information on ongoing or upcoming research projects, events, grants, or awards. Engage with colleagues, supervisors, or administrators to learn more about their research interests and activities.

  1. Research out to potential collaborators and mentors

One of the key skills for a researcher involves reaching out to potential collaborators and mentors who can provide valuable feedback, guidance, and opportunities. However, many researchers face challenges in initiating and maintaining such professional relationships. Here are some effective tips for conducting research outreach:

– Clearly define your goals and interests before reaching out to anyone. Determine what you aim to achieve through collaboration or mentorship and what you can contribute in return. Whether it’s learning a new method, working on a specific project, or seeking career advice, consider how you can contribute to their research or objectives.

– Conduct thorough research on the individuals you intend to contact, including their background, publications, and current projects. Tailor your message to reflect your genuine interest and enthusiasm, and identify common connections, such as mutual colleagues, institutions, or interests, to establish rapport.

– Craft a concise and polite email for your initial contact. The first impression is crucial, so ensure your email is well-written, professional, and respectful. Briefly introduce yourself, explain the purpose of your contact, articulate what you hope to gain from the interaction, and inquire about their availability and preferred mode of communication. Be specific about your request yet remain flexible and considerate of their time and priorities. If relevant, attach your CV or portfolio, and provide a link to your website or profile.

– Follow up and maintain communication. If you don’t receive a response within a reasonable time frame, consider sending a gentle reminder or follow-up email after a week or two. However, avoid being overly persistent or pushy to prevent annoyance or pressure. If they agree to a conversation, prepare questions or topics for discussion, and be punctual, courteous, and attentive during the conversation. Express gratitude for their time and insights and follow up with a thank-you email afterwards. If they suggest any action items or next steps, promptly follow through and keep them informed of your progress.


For more information, feel free to contact the BCI internal newsletter team at

Real-time Quality Control in Automated Fibre Placement using Artificial Intelligence 

by Gabriel Burke, Duc H. Nguyen, Iryna Tretiak.

The growing demand for ever more cost and labour effective production of large, lightweight, and geometrically complex composite structures has led to the replacement of traditional manufacturing processes, such as hand lay-up and vacuum bagging, with automated processes such and Automated Fibre Placement (AFP). The AFP method uses robotic arms to deposit layers of carbon fibre reinforced composites (CFRP) onto bespoke moulds. This process can create complex shapes at high speed. However, manufacturing-induced defects are inevitable during AFP. This degrades the strength of the final parts and creates a major waste problem, with defective parts discarded in some cases. While automation of composite manufacturing processes has been successfully industrialised, inspection is still largely a manual process.

As we move towards Industry 4.0, it is possible to optimise inspection during the AFP manufacturing process. One option of improving inspection is to implement artificial intelligence.

Our research team at the Bristol Composites Institute (BCI) has successfully designed and implemented a system that performs real-time defect detection and classification during the AFP process, providing information on the location and type of defects in the tape almost instantly after it has occurred.

The developed system is built upon a convolutional neural network (CNN), which uses deep learning techniques to detect defects based on input data images. These images were generated using data collected from a Micro-Epsilon profilometry sensor attached to the AFP gantry. This system can correctly identify and differentiate between three defects (fold, twist, and pucker) and does so in real-time using a three-stage algorithm:

1. Live data collection and pre-processing;

2. A sampling and image optimisation algorithm to produce a moving window of input images for the CNN;

3. Defect detection/classification using the CNN.

Due to this modular design, it is possible to modify each stage to fit the needs of other AFP applications. For example, the CNN can be retrained to ‘look’ for other defects, or the sampler could be modified to collect images at a different frequency based on the scale of the part being manufactured.

This novel inspection technique provides great potential to improve efficiency and reduce waste in composites manufacturing.


Following the success of the initial proof-of-concept phase, the team is looking to upscale the current prototype to meet the speed and robustness requirements of operational systems in industry. 

Industrial Doctorate Centre in Composites Manufacture: Showcase 2023

The Industrial Doctorate Centre welcomed over 40 guests to the annual Showcase event, on the 19th September 2023, held at the Watershed in Bristol. The event was followed by a gala dinner at Bristol Harbour Hotel.

The Industrial Doctorate Centre in Composites Manufacture has now reached its 10th year, and over this time, 31 students have graduated with an EngD in Composites Manufacture. The day before the event we welcomed five new students to the IDC, bringing the total number of students currently enrolled to 20. The new students were excited to attend the Showcase along with existing IDC students, alumni, academic and industrial supervisors, and joined by a group specially invited  VIP guests, with strong connections to the UK composites sector. It was a great opportunity for students to present their research work to a wider audience and network within the industry.

The day consisted of 3 oral presentations sessions and a quick-fire poster session all chaired by the IDC alumni. The presentations from our students ranged from topics in advanced manufacturing techniques, new approaches to testing wind turbine blades, process simulation and effect of cryogenic exposure on composites. A focus of the showcase was sustainability, this was brought in to context in a fantastic keynote speech from Dr Ffion Rodes. One of the ambitions for the IDC is for our students to create their own spinouts and companies. Dr Tomasz Garstka a PhD alumni from Bristol Composites Institute has done just that creating his company LMAT. Tomasz gave an excellent keynote presentation  on how he turned his academic research into a commercial tool for composite tooling.


The Showcase ended with a very lively panel discussion, chaired by Professor Mike Hinton of the High Value Manufacturing Catapult. The panel comprised  Dr Anna Scott Magma Global; Dr Petar Zivkovic Airbus; Dr Peter Giddings NCC; Dr Faye Smith, Avalon Consultancy; Professor Paul Hogg, Royal Holloway University of London; Janet Mitchell, MC2Consultants.

The panel were asked to discuss how can industrially-based doctoral research help unlock the potential of composites in achieving a Net Zero? The topics discussed included: Understanding better how digital technologies can help accelerate our learning; start thinking of composites as an enabler to protect our way of life by integrating sustainability at the design stage, creating a template for LCA that can be used in all projects; extended in-service life of composites and life extension programmes; smarter testing to reduce waste and move to virtual tests for certification; take steps to eliminate trial and error approaches in manufacturing; move away from the driven by rate approach.

The event was a great success with engaging discussions throughout the day carrying on into the evening at the reception and the gala dinner.

Professor Janice Barton, Director of the IDC was delighted with the day and said “It was fantastic to see our students present their work with confidence and realising they are making a significant difference to their sponsoring companies and to wider society”.

Process Simulation For Reduced-defect Composites

by Siyuan Chen, Stephen Hallett and Jonathan Belnoue.


As the demand for carbon fibre-reinforced composites structures is rapidly growing, the industrial community continues to seek new manufacturing technologies that are low-defect, low-cost, highly efficient and environmental-friendly. Liquid molding is regarded as a cheaper alternative to the traditional prepreg/autoclave approach, however, the latter is often the favoured manufacturing route in the aerospace sector (where safety is paramount) as it allows for the production of better quality parts. One of the many challenges with infusion is the high deformability of the dry fibrous precursor materials that exposes the final structure to risks of defects and part to part variability. If the material and process (including their variabilities) are not controlled to a sufficient level, meeting design tolerances can prove challenging. These risks are traditionally mitigated through “over design” but this reduces a lot of the lightweighting advantages of using composites. 

At BCI, we explore the possibility of achieving reduced-defect forming processes in 3 different ways. Firstly, design tools accounting for manufacturing constraint that are faster than current methods available commercially are being developed [1, 2]. These tools can be used to run moderate numbers (i.e., up to a 100) of simulations and allow to explore the impact of different combination of process control parameters on final part quality. This provide the possibility of optimising the forming process. The robustness of the optimisation is then improved by building Gaussian process (GP) emulator using the dataset produced using our fast simulation tools [3]. These GP emulators can achieve a good accuracy (error < 10%) and model the impact of several input parameters by running only tens of simulations. By introducing dimension reduction and active learning algorithms, the emulators can be expended to much more complex processes with over 10 input parameters [4]. After being trained, the emulators can also provide immediate predictions for final part quality. This open the door for digital twinning where in-process sensing and real-time simulation are combined. Thus, although forming processes can be optimised using deterministic FE simulations, real-world cases are affected by lots of factors such as material and process variability. Some of these variabilities are difficult to avoid but can be measured. Quantifying them (e.g., fibre direction misalignment, tow waviness, etc), a feedback loop whereby real-time simulations are informed by live data of the process and used to adapt the manufacturing condition to improve the final part quality can be set. A forming test cell instrumented with a stereo imaging system is currently being built in our labs. This will be used to construct a prototype digital twin for forming process. 

To summarise, in our vision right first-time design and manufacture of composites can be achieved through a combination of (physics-based) digital design accounting for manufacturing constraints, fast process optimisation using data generated from process models and self-adapting manufacturing hardware controlled through emulators build from process models. 



[1] Composites: Made Faster – Rapid, physics-based simulation tools for composite manufacture ( 

[2] JPH Belnoue, SR Hallett A rapid multi-scale design tool for the prediction of wrinkle defect formation in composite components, Materials & Design, 2020. 

[3] S. Chen, A.J. Thompson, T.J. Dodwell, S.R. Hallett, J.P.-H. Belnoue, Fast optimisation of the formability of dry fabric preforms: A Bayesian approach, Materials & Design, 230:111986, 2023. 

[4] S. Chen, A.J. Thompson, T. J. Dodwell, S.R. Hallett, J. P.-H. Belnoue. A Bayesian surrogate framework for the optimisation of high-dimensional composites forming process. In 5th International Conference on Uncertainty Quantification in Computational Science and Engineering, 2023. 

Moving cheese: energetically efficient shape shifting via embedded actuation

Compliant materials and slender structures are susceptible to a variety of different instabilities under external stimulus or loading. Traditionally, these instabilities are avoided and classified as failure modes. In recent years, researchers at the BCI have instead attempted to use complex nonlinear behaviour for novel functionality. Simply put, if nonlinearities are understood, then they can be exploited to create well-behaved nonlinear structures. In a recent publication in Physical Review B [1], we employed ‘active modal nudging’ as a novel actuation mechanism for soft robots. In essence, we programmed a soft metamaterial to shape-shift in a rapid and energetically efficient manner by employing embedded actuation to switch between different stable post-buckled modes. 

Our work focused on a latticed metamaterial consisting of an elastomeric matrix with a 3 by 3 square array of circular holes, as shown in Figure 1. We discovered that this metamaterial has three stable post-buckling modes under pure compression, i.e. two sheared modes (sheared left and sheared right) and one symmetric polarised mode. The metamaterial was programmed to favour one of the sheared modes under axial compression via modal nudging [2]. An actuator was then embedded within the central hole to trigger a mode switch between the favoured sheared mode and the polarised mode. We demonstrated that this combination of active and passive nudging is more energetically efficient and requires smaller actuation force than the more widely used global actuation method, as shown in Figure 1(a). By toggling the metamaterial between the sheared and polarised state, we were able to make the metamaterial crawl. The effective locomotion could be employed in soft robotics systems (Figure 2). 

While in this study, we consider a specific type of soft metamaterial and a specific application, the design paradigm introduced can be extended to other scenarios where energetically efficient shape shifting may be beneficial, such as lightweight adaptive wing structures or adaptive façade and ventilation systems for net-zero buildings. 

Figure 1 The actuation force–displacement curve of the lattice metamaterial to achieve a us/L = 0.20 shear displacement amplitude, using: (a) increasing compression from the pre-buckling state; and (b) active nudging from the symmetric deformation mode. 



Figure 2 (a) A typical actuation cycle for the robot. Yellow and red lines are the reference line indicating the initial and final positions of the right and left edges. The yellow arrows represent the motion of the fixture within the step. (b) The location of the crawling robot in the initial state, after four and eight iterations. A movie of the movement of the demo robot can be found in 




[1] Shen, J., Garrad, M., Zhang, Q., Leao, O., Pirrera, A., & R. M. J. (2023). Active reconfiguration of multistable metamaterials for linear locomotion. Physical Review B, 107(21), 214103. 

[2] Cox, B. S., Groh, R. M. J., Avitabile, D., & Pirrera, A. (2018). Modal nudging in nonlinear elasticity: tailoring the elastic post-buckling behaviour of engineering structures. Journal of the Mechanics and Physics of Solids, 116, 135-149. 

BCI’s contribution to NCC’s Technology Pull-Through (TPT) programme, 2023-24

The Bristol Composites Institute (BCI) was involved in both of the projects funded by the NCC in their 2023/24 Technology Pull-Through (TPT) programme, directly aligned with the NCC’s composites strategy. The TPT programme stimulates the transition of suitably mature technologies to industry and is aimed at technologies and methods that are ready to advance from a laboratory environment, typically at Technology Readiness Level (TRL) 3 to 4. One is based on Healable Interfaces, to demonstrate the viability of vitrimer composites for use in repair and end-of-life disassembly, whilst the other is focussed on the standardisation of cryogenic H2 permeability testing in composites, through the development of a test rig to provide testing guidance and data on variance in measurements in this type of testing of composite materials. The Healable Interface work is being conducted by Joe Soltan, working with NCC colleagues, Janice Barton, Dmitry Ivanov and James Kratz, and the Cryogenic Permeability Testing is being conducted by Lui Terry, with NCC colleagues and Valeska Ting. 

Healable Interfaces 

The major challenge in composite repair is that it is costly, a specialist activity, limited by geometry and largely requires cutting of reinforcing fibres, resulting in structural discontinuities. Additionally, in-field repair is typically only possible on a small number of small damage events, and current composite solutions do not offer a viable circular economy approach. The project aims to demonstrate the viability of vitrimer composites for use in repair and end-of-life disassembly. The potential benefits are: 

  • to enable in-field repair, and therefore the extension of service life and the sustainability of composite solutions 
  • to offer the possibility of disassembly through a simple breakdown method at end-of-life, enabling a better circular future for composites 
  • to de-risk composite processing through modular infusion methods 

The project focus is on skin and stiffener interfaces within wind turbine blade structures, although this technology would be relevant to a whole host of other composite applications. Work to date has included a down-selection candidate vitrimer systems, laboratory trials encompassing processability, thermal characterisation and initial mechanical testing to identify an ideal healable interface vitrimer. Future work will develop recommended manufacturing processes and cycles for healable interfaces, and prove the technology for skin/stiffener wind turbine blade structures. Sustainability impacts will provide the projected trade-off point between additional embodied energy and service life extension. At completion, it is envisaged that the application of emerging vitrimer materials in a circular composites industry will have been demonstrated. For further information, please contact Joe Soltan ( 

Cryogenic Permeability Testing 

The decarbonisation of the aviation industry is contingent on composite materials for cryogenic LH₂ storage. A key issue holding back the technology is that hydrogen permeability through composite materials at cryogenic temperatures is relatively unknown as a result of the scarcity of testing facilities able to reach the cryogenic temperatures (20 K) and a high degree of variability between existing datasets. The barrier is therefore due to a gap in the measurement infrastructure, and a lack of validated measurement standards or guidance on testing cryogenic H₂ permeability in composite materials. This project aims to develop a cryogenic H2 permeability test rig and to provide guidance for cryogenic H₂ permeability testing of composite materials, to help quantify the variance in measurement data that can be expected. The anticipated benefits are: 

  • a reliable and validated cryogenic H₂ permeability method for composite materials 
  • an experimental rig that can be extended in the future to examine interface design between composite and metallic materials 

To date, a cryogenic hydrogen permeation rig (CHyPr) has been designed and built at BCI. The first generation of CHyPr will measure permeability in any solid material between 0 to 80 bar, and from 77 to 293 K. The design and materials selection process for CHyPr however, has accounted for the expansion of the rig to encompass 20-475 K and 0-200 bar in future generations. A reusable permeation cell has been designed and manufactured, capable of measuring both through and lateral permeation of cryogenic hydrogen and now has passed the relevant pressurised equipment safety certification for use. Currently, CHyPr is undergoing calibration and validation of its seals before initial sample testing can begin. This project also involves two other partners, the National Physical Laboratory (NPL) and the University of Southampton, to complete a round-robin benchmarking study of cryogenic hydrogen permeation testing. This aims to determine the current data variance levels between test houses and to isolate the determinant factors in methodology that cause that variance. It is intended to develop guidance in this nascent field on how to better control these variables to ultimately contribute towards a standardised method for cryogenic permeability testing in composite materials. For further information on CHyPr, please contact Dr Lui Terry (

BCI’s Research Associate awarded Young Researcher Award at International Conference

Bristol Composites Institute’s (BCI) Research Associate, Yi Wang attended the 12th Asian-Australasian Conference on Composite Materials (ACCM12) in Hangzhou, China from the 25th to the 28th of April. Yi won the Young Researcher Award for his talk entitled “An automated workflow for composites part manufacturability prediction and tooling optimisation”. Yi was presented the award by BCI’s founder and former director Professor Michael Wisnom who also attended the conference.

Four people pictured with their awards

Yi has been a member of our process simulation team for a number of years working originally as a PhD student within the EPSRC SIMPROCS platform grant before becoming a Research Associate working on the same project. He now works on our latest EPSRC grant: Composites: Made Faster. Yi’s talk presented the outputs from our work on the research program DETI led by the National Composites Centre (NCC) and funded by the West of England Authority. This research developed, at an industrial scale, an automated workflow for the prediction of manufacturing-induced defects in autoclave-moulded thick composite parts. It builds on the robust consolidation model and homogenisation approach developed at  BCI in the last 10 years.

The work also laid the foundation to conduct data-driven optimisation of caul plate geometries for reduced geometrical deviation from part design. Wide adoption of these tools could allow saving industry a considerable amount of time and money by removing a large number of the many physical trials that are currently an integral part of any composite part manufacturing process development.

Yi’s supervisors Dr Jonathan Belnoue and Professor Stephen Hallett said: “Congratulations to Yi for this achievement. Yi is a very important member of the team who brings great enthusiasm to anything he puts his hand to. A very well-deserved award! This is also great recognition of the quality of BCI process simulation work that has advanced considerably over the last 10 years”.

Developing high-value lignin and cellulosic materials from animal dung

Fabrizio Scarpa and Adam Willis Perriman


A recent review work carried out at the BCI in collaboration with the Scotland’s Rural University College and the University of Edinburgh has identified several routes to obtain crude biobased materials, composites, and purified derivatives from manure. The paper is open access and can be found here:

Manure can be considered as an unlikely source of biomass. It is rich in lignocellulose components like cellulose, hemicellulose, and lignin. Renewable biomasses provide a global yield of 200 billion metric tons per year of lignocellulose, yet the separation of the biobased components requires a combination of energy-intensive physical and chemical processes.
Herbivores (and ruminants, in particular) have however highly developed digestive organs able to break down the lignocellulose. Lignin reinforcements obtained from cattle dung have shown a very promising performance in terms of matrix adhesion to phenolic resins. The digestion process of ruminants like cows contributes to an enhanced surface structure of the biobased fibres, which favours bonding with different matrices.

A similar enhancement of bonding between phenolics and reinforcement obtained from elephant dung is not however present. Elephants are monogastric and lack the foregut fermentation that cows provide. The diversity of the bio chemo-physical origins of animal manure therefore constitutes a challenge to manufacture composite materials with unique production processes. Nevertheless, composites made from animal manure components are mixable with a wide variety of thermosets and thermoplastics, making them appealing for secondary load-bearing applications across the industries.

Quite significantly, manure could be used to extract nanocellulose, which it has a huge potential for use in a wide variety of applications, from structural to antibacterial agents, fuel cells, and biomedical applications. Current production methods of nanocellulose are energy intensive, while the use of enzymes in biomass has been hailed as a low-cost methodology for production. Animal ruminants and in particular cattle can provide an alternative way to produce at larger scales nanocellulose and other lignocellulose-based components, because we can make use of the existing large-scale supply chain in the agricultural and livestock business existing in the UK and beyond. Never has the old saying: “Where there’s muck, there’s brass” sounded truer.”

Smart tooling for Energy Efficient Composite Manufacturing

Radhakrishnan, A., Maes, V.K., and Kratz, J.

Conventional oven-based curing of thermoset composites is an energy-intensive process. This arises from the inefficient heating of a large volume of air combined with tooling that is typically 10-40 times heavier than the composite part manufactured on the tool. This large thermal mass potentially leads to a larger cure gradient, i.e., spatial change in temperature within the composite parts, and manifests as distortion or residual stresses both causing part failure, higher scrappage, and increase cost. Cure gradients can further be made worse by the exothermic reaction causing thick regions to become local hot spots as the part cures. To avoid cure gradients, manufacturers generally apply slow heating rates to allow heating to even out and reduce exothermic peaks. These slow heating rates in turn increase cycle times and energy consumption. Thus, the manufacturer is caught between the two competing priorities of quality and production rate. To push production rates while maintaining part quality, smart tooling solutions are required.

Researchers at the Bristol Composites Institute (BCI) typical features such as corners and ramps to evaluate two innovative approaches improving part quality while reducing cycle times and energy consumption: 1) direct zonally heated tools and 2) additively manufactured (AM) metal tools (Figure 2).

Graphic illustration showing test results









Figure 1. Benefits of out-of-autoclave curing of a complex part using zonally heated tooling with direct heating compared to using an oven.


Graphic showing the benefits of using AM Tool instead of a solid tool for curing complex part





Figure 2. Benefits of using AM Tool instead of a solid tool for curing complex part

Heated tooling introduces heat directly to the tool surfaces or volume through heated fluid circulation or heating elements. While this process reduces energy consumption by 45% compared to traditional oven or autoclaves curing process, as illustrated in Figure 1, the cost of heated tooling can be high. However, the true potential lies beyond energy efficiency, but rather in the ability to tailor the temperature profile applied to different regions. By introducing zonal heating, 17% faster cure cycles can be achieved while reliably ensuring high quality by reaching moulding temperatures quicker and more spatially uniform by the cure profile at the thick and thin regions (Figure 1). This allows for greater throughput, which ultimately results in cost savings and increased production capacity using a smaller factory footprint. Therefore, while the initial investment may be higher, the long-term benefits of zonally heated tooling make it a promising option for industrial applications.

In the feasibility study funded by the University of Bristol EPSRC Impact Acceleration Award, we explored the application of cure-kinetic coupled numerical simulations to design cure cycles for single and dual-zone heated tooling. The numerical predictions of the thermal profile were successfully validated experimentally using embedded thermocouples in the manufacturing of complex parts. The independent zonal thermal control approach reduced the spatial gradients in temperature and degree of cure without worsening the exotherm. Further developments are underway in applying machine learning, in-situ sensors, and advanced thermal management for adaptive cure control to manage heating as well as cooling to reduce overall cycle time and energy.

Additive manufacturing is one such enabling route that was explored in our feasibility study with the University of Bath funded by CIMComp Future Composite Manufacturing Research Hub. The use of AM removes design restrictions placed on monolithic tooling manufactured via subtractive processes like machining and milling. In the study, we explored lattice-based metal tooling manufactured via powder bed fusion for efficient composite curing. Lattice structures have repeating unit cells, and selecting the appropriate unit cell can improve thermal and structural properties like heat transfer and stiffness. Our work investigated a series of flat tools with a range of parameters including lattice geometry, density, and face sheet thickness to assess AM capabilities in meeting tooling requirements such as dimensional tolerances, stiffness and heating rate and found gyroid lattices performed exceptionally well. This lattice architecture was then translated to produce a tool for manufacturing a complex geometry

Direct zonal heated tooling reduced cycle time by 17% and energy by 45% while improving part quality with a reduced cure gradient. Combining this approach with AM tooling resulted in an additional 20% reduction in cure cycle time and a 45% reduction in energy use. Compared to conventional solid tooling using oven curing, the direct heating and AM design saved around 35% in cure cycle time and 70% in energy use. Future work on these innovative tooling concepts can have a considerable impact, particularly in designing cost-effective and energy-efficient tooling for manufacturing high-quality composite parts.

For further reference:

Zonally Heated Tooling for Moulding Complex and Highly Tapered Composite Parts|Frontiers|2023

A Feasibility Study of Additively Manufactured Composite Tooling| IAM2022 Proceedings| 2023





A Digital Twin for Composites Feedstock Characterisation

Koptelov A., Belnoue J.P-H., Georgilas I., Hallett S. R., Ivanov D.S.

The complexity of composites manufacturing stems from the nature of composite precursors—the combination of loosely-joined fibre network and liquid viscous resin—often heterogenous and enhanced with tougheners or functional additives. is compliant, deforms irreversibly, exhibits almost negligible resistance to axial compressive stresses and has a multitude of flow/deformation mechanisms (i.e., the internal or percolation flow of resin, flow of fibrous suspensions, densification of reinforcement, relative movement of plies, and others) – Figure 1. This makes precursors prone to defects at all stages of the composites manufacturing process.

One of the fundamental processes, universal almost for the entire range of composites manufacturing methods, is consolidation, where a composite precursor undergoes compression to engage plies in contact, squeeze out volatiles, control fibre volume fraction and thickness, obtain near-net component shapes, etc. This is a quality-critical process – deformability of composite precursors defines their susceptibility to defects, their compliance with dimensional tolerances, and the occurrence of shape distortions.

Example of flow mechanisms in the same prepreg at different processing conditions

Different forms of deformation mechanisms take place at different structural scales and often occur in parallel. It is essential to have a comprehensive understanding of all these processes to predict the evolution of precursors throughout all stages of composite processing and assess the final architecture/ properties of the composite structure. Each of these mechanisms can be described by material models with various formulations involving large number of material parameters that cannot be determined from direct experiments.

A potentially dangerous trap is that available experimental data are often limited as material testing is both complicated and time consuming. The information obtained in these tests may appear to be deficient and may not reveal all the underlying processes. In this case, property identification may provide a seemingly good fit irrespective of which mechanisms is presumed to happen. However, it does not mean that such model represents the physical reality, and it can often fail to adequately represent a wider set of experimental data. This sets a fundamental dilemma, as the material behaviour (i.e., the model selected) needs to be decided prior to conducting the tests, which introduces a strong subjective element. There is, therefore, a need for a new testing methodology that is capable to identify the deformation mechanisms as well as the relevant material properties. This methodology should be able to check different hypotheses on the deformation mechanisms and autonomously design a testing program based on the measured behaviour of the material.

We have recently developed such adaptive framework [1,2]. It presents a system for autonomous characterisation of materials subjected to an application of pressure and temperature. The system comprises conventional testing machine with heat plates and an integrated “digital brain”, which allows to make decisions on loading path in real time in a “conversation” with material and without human intervention – Figure 2.

Figure of Autonomous testing setup

Figure 2. Autonomous testing setup

The framework automatically identifies the characteristic flow processes and the properties associated with the correspondent deformation mode, such as viscosity. As a result of the process, the framework creates a reliable digital twin of the material representative over large range of processing parameters. The fully functioning prototype has been successfully tested for various material systems including toughened prepregs and dry fabrics. These curves are rather different from conventional loading programmes and show the complexity of testing needed to identify the underlying deformation mechanisms.

Figure 3. Real time characterisation (A) IMA/M21 prepreg, (B) IM7/8552 prepreg: purple - chosen trajectories, black - thickness samples response.

The digitally-driven framework does not just test the material, it defines which flow mode is happening within it and is capable of sensing fine characteristics of material state. The material properties come as a by-product of such examination. This methodology leads to reduced number of experiments while making sure that the obtained data is representative and sufficiently captures all the main features of the material behaviour.


  1. Koptelov A., Belnoue J.P-H., Georgilas I., Hallett S. R., Ivanov, D.S. Revising testing of composite precursors – a new framework for data capture in complex multi-material systems, Composites Part A, 152 (2022) 106697.
  2. Koptelov A., Belnoue J.P-H, Georgilas I., Hallett S.R., Ivanov D.S. Adaptive real-time characterisation of composite precursors in manufacturing, Frontiers in Materials, 214.