Bristol Composites Institute Blog

iCOMAT opens doors to CoSEM and BCI visitors

Posted on 11/12/202511/12/2025 by jo.rich

On Tuesday 11 November 2025 iCOMAT welcomed CoSEM and BCI students for a site visit to its facility in Gloucester.

The visit showcased iCOMAT’s patented Rapid Tow Shearing (RTS) process — a breakthrough technology that allows carbon fibre prepreg tapes to be steered without producing defects, resulting in lighter, stronger and more sustainable structures. iCOMAT was co-founded by Dr Evangelos Zympeloudis and Dr ByungChul (Eric) Kim, and was spun out from the Continuous Tow Shearing (CTS) technology first invented at the Bristol Composites Institute (BCI), at the University of Bristol.

Students on the guided tour of the iCOMAT factory

The day began with a welcome and opening presentation from Mike Peacock, Head of Operations. This was followed by a series of presentations from David Sutherland, Director of Engineering; Francisco De Sa Rodrigues, Forming Simulation Engineer; Vasileios Sigalas, Head of Growth; and Stefanos Petropoulos, Senior Mechanical Engineer.

Together, the speakers covered the history and evolution of RTS, iCOMATs engineering and simulation capabilities, and their rapid growth and career opportunities.

Following the presentations, attendees donned lab coats for a guided tour of the factory, where they observed RTS machines and viewed the company’s large autoclave. Throughout the tour, the team emphasised iCOMAT’s end-to-end capability.

CoSEM & BCI students in front of iCOMATs large autoclave

After the tour, attendees enjoyed a networking lunch, engaging with iCOMAT team to learn more and ask questions. The visit concluded with presentation from CEO and Co-founder Evangelos Zympeloudis.

Reflecting on the visit, Ronald Mwesigwa, CoSEM CDT23 student said: “Seeing how a research idea like Continuous Tow Shearing has evolved into the industrial Rapid Tow Shearing process was incredibly inspiring. It showed us how innovation in composites can have a real, tangible impact on sustainability and design.”

Image credit: Jenna Cantillion iCOMAT

Optimisation of multi-rotor wind turbines for reduced cost of energy and environmental impact

Posted on 09/12/2025 by jo.rich

Abdirahman Sheik Hassan, Neha Chandarana, Rainer Groh, Terence Macquart

The Big Picture

Multi-rotor wind turbines (MRWTs/MRs) are a promising solution to many of the problems facing the wind energy industry in its mission to scale up renewable capacity and address the ongoing climate crisis. MRWTs use an array of smaller rotors on one support structure, as shown in Figure 1, in place of the ever-growing single-rotor concept. The inherent scaling advantage of this architecture can offer significant mass and cost savings, while simultaneously alleviating challenges in transportation, manufacture and aeroelastic stability associated with large wind turbine blades. From the launch of the OceanX dual-rotor platform in China, to the planned construction of the Wind Catching demonstrator in Norway, the concept is moving up the technology readiness levels from theoretical economies of scale to practical solutions. While these demonstrators will shed light on the practical feasibility of the concept, little is known about the true extent of the benefit it can offer over the existing single-rotor paradigm.

Figure 1: Mingyang OceanX dual turbine platform [1] and Wind Catching System’s Wind Catching Demonstrator model [2].

Our Research Aim

Our work aims to provide further confidence in the feasibility of the multi-rotor concept through detailed modelling, analysis and by employing coupled aeroelastic optimisation to minimise the levelised cost of energy. We recently published a review on multi-rotor technology (tinyurl.com/4b4pnypm) and highlighted the need for comprehensive design studies to quantify the benefits of the multi-rotor concept in comparison to conventional designs.

An Open-Source Library to Support Research in the Multi-Rotor Concept

To address this gap, the ATOM aeroelastic software package from the University of Bristol has been expanded to model and design MRWTs, using blade element momentum theory coupled with multi-body dynamic finite element analysis. Enabling this process requires detailed virtual rotor models fit for the MR context. We tackled this problem with our recent work presented at the Multi-Rotor Seminar in Hamburg (tinyurl.com/4vpwbp64) on the generation of an open-source library of reference rotors for use in MRWT modelling. Optimised rotor models with ratings ranging from 100kW to 1MW are generated and shared in the OpenFAST format, allowing researchers to study and compare a large range of multi-rotor configurations.

Holistic Concept Design

Aiming to achieve a “globally optimised” MRWT, the individual rotor-level optimisation enables the assessment of optimal rotor number for a given overall rated power. Figure 2 demonstrates the use-case of these models – the ability to assess the optimal number of rotors by rapidly exploring a large number of different configurations with detailed rotor and support structure models.

Figure 2: Multi-rotor models constructed using rotor designs from the rotor design library. These include three 1 MW rotors, fifteen 200 kW rotors and seven interpolated 428.6 kW rotors.

An Opportunity for Greener Wind Energy

Working in collaboration with the National Composites Centre we are exploring the potential of MRWTs as an enabling technology for the use of sustainable materials in wind turbine blades, due to their smaller rotor size and reduced structural requirements. Ongoing work investigates the dual-objective optimisation of the rotor models in the rotor design library for the minimisation of both cost of energy and environmental impact.

[1] Mingyang Smart Energy. Retrieved October 2nd, 2025, from https://en.myse.com.cn/

[2] Wind Catching Systems. (n.d.). Retrieved September 23, 2025, from https://www.windcatching.com/

BCI Alumni Q&A: James Lightfoot

Posted on 08/12/202508/12/2025 by jo.rich

James Lightfoot shares his progression from completing a PhD to driving innovation in renewable energy at SSE Renewables…

Why did you choose the Bristol Composites Institute for your studies?
Coming to the of end my undergraduate degree in biochemistry I was very keen to explore a career change. After a long discussion with Paul Weaver in Queens Building, I was enthused by the high-impact nature of the R&D, the industrial links within the department and the commitment to invest in skills and training from EPSRC. BCI gave me the opportunity to retrain with a cohort, which gave me the chance to learn and develop with a group of like-minded PhD students.

What research area did you specialise in whilst you were here?
I was in the inaugural year of what was called the “ACCIS DTC” in 2009. I specialised in composite manufacturing and did a PhD on defects formed during the manufacturing process of propeller blades, under the supervision of Kevin Potter and Michael Wisnom and GE Aviation. My PhD included elements of manufacturing process modelling and lots of hands-on manufacturing. I also learned to layup a Dowty propeller blade which was a fantastic experience.

After leaving the BCI where did you go?
I spent three years at Frazer-Nash Consultancy where I spent much of my time carrying out finite element modelling of metallics in aerospace gas turbines and composites for the automotive industry. I then spent almost seven years at the National Composites Centre (NCC) as a Technical Programme Manager. At the NCC I was lucky enough to lead the renewable energy team and portfolio, meaning I worked alongside the likes of Europe’s biggest turbine manufacturers to help them make better turbine blades. This included 3D printing of continuous fibre composites, digital twins of blade curing and developing composite turbine towers for floating offshore wind.

What are you currently working on and what do your future plans look like?
I’ve since moved to SSE Renewables and have led on sustainable innovation for over two years, covering onshore and offshore wind, hydroelectric power and battery storage. I still work with composites, though I spend most of my time trying to recycle our blades, which can be over 100m in length and over 50 tonnes in mass which isn’t particularly easy. With the diversity of our business I’ve had to learn a lot, from making our onshore wind foundations more sustainable, through to decarbonising offshore wind with zero emissions vessels. Working in renewable energy is fantastic and I’ll likely stay in the industry for some time.

How did the BCI prepare you for work outside of academia?
As I retrained to composites in the first year of the doctoral training centre my time at BCI helped me to rapidly understand new concepts, tools and techniques. This was critical to picking up the broad range of projects whilst working at Frazer-Nash. The massive range of composites work, from process modelling to making and breaking 3m wingboxes, gave me a huge breadth of knowledge of experience for me to lean on whilst at the NCC. My PhD also helped me develop transferable skills, the most important being talking to a range of stakeholders about very technical ideas, which is essential in my professional life.

BCI Alumni Q&A: Vishnu Muraleedharan

Posted on 08/12/202508/12/2025 by jo.rich

Now working for Rocket Lab, Vishnu Muraleedharan shares his journey from MSc to Composite Engineer…

Why did you choose the Bristol Composites Institute for your studies?
I was already working as a composite engineer at Verdant, an aerospace company based in India, loved it and was considering doing a Master’s in Composites, abroad. I did my research – everything related to studying abroad, benefits and challenges. I wanted to get into a University which is reputed, has strong research and industrial ties, in a vibrant city and proximity to aerospace companies. I figured all of these would help me in my career and life moving forward. I short listed a few universities- but University of Bristol stood out. Filton being an aerospace hub and close to University, and knowing the University already have research collaboration with many – I considered that as a good opportunity to grow my network and possibly leverage that for a career in composites in UK. Beyond that it was the history, heritage and beauty of the University and the city that attracted me. Although I was not able to utilize the opportunity to the best due to Covid, life had a different plan for me.

What research area did you specialise in whilst you were here?
I was in a taught Master’s programme, therefore there wasn’t a lot of research except my thesis. But during the course works, I enjoyed topics related to materials, and processing of composite material, specifically carbon prepreg composites. I still remember one particular course work, where I was reviewing applications of carbon composites in bicycles and how leading bicycle manufacturers use carbon for their sporting bikes and their patented processes. For my final thesis, I manage to collaborate with then Rimac Automobili, current Bugatti Rimac and I focused my research on methods to improve Noise, vibration and Harshness (NVH) properties of carbon composites. I was drawn to the use of visco-elastic materials to dampen vibrations. The thesis itself was quite heavily dependent on FEA and working with viscoelastic materials was challenging. Although, the thesis was quite interesting, it made me realise FEA is not for me. I’m someone who wants to work hands-on. Maybe it was hard because I wasn’t enjoying it much, but it was an important learning for me. I found out something I would not want to take up as a career.

After leaving the BCI where did you go?
I often find networking as key factor of working in an industry. Although big, the composite industry is quite tight-knit. Everyone knows someone, or someone who knows someone. It was through contacts I made from my previous job that I managed to collaborate with Rimac for my thesis. This later led to a job interview and I was offered the role of Composite Manufacturing Engineer, which moved me to the exciting world of Hyper cars, in the beautiful country of Croatia.

What are you currently working on and what do your future plans look like?
I joined Bugatti – Rimac in the beginning of 2022. I was predominantly involved in the productionizing of Rimac Nevera and the Development of the Bugatti Tourbillon – which will always remain as the highlight of my career. After three great years at Bugatti-Rimac, I got offered a role in Rocket lab in New Zealand. Since early 2025, I’ve been working as a Composite Engineer for Rocketlab, for their launch vehicles – Electron and Neutron. I say to my friends “I went from building rockets on the road to actual rockets”. My future plans are not solid yet, but it’s safe to say my future remains in composites and playing it by ear. I’m open to where my career takes me and remaining positive it’s all for good.

How did the BCI prepare you for work outside of academia?
Bristol being a Research University and BCI being very close with industry – there is a culture that you are provided with the support and knowledge, but it is up to each individual to use those opportunity to make something valuable out of it. People around me were intelligent, driven, hardworking and passionate – that kept me humbled, grounded and motivated at the same time. I learned how to approach complex problems independently and at the same time learned when to seek help – which I think is a must have quality in an industry work environment.

BCI Alumni Q&A: Rafael Iglesias

Posted on 08/12/202508/12/2025 by jo.rich

Rafael Iglesias shares his journey from PhD to lecturer in Biomedical Engineering at Universidad Francisco de Vitoria in Madrid…

Why did you choose the Bristol Composites Institute for your studies?
My decision to pursue my PhD studies at the Bristol Composites Institute was largely influenced by the CERTEST project, which brought together more than twenty researchers from different fields such as computational mechanics and experimental mechanics. In addition, the BCI is internationally recognised as a leading centre in the field of composite materials — an area in which I had already decided to specialise in some time ago.

What research area did you specialise in whilst you were here?
I specialised in thermal imaging and digital image correlation applied to composite laminates. Under the supervision of Professor Janice Barton and with the support of my colleagues, I focused on thermoelastic stress analysis of CFRP laminated materials and studied their behaviour under non-adiabatic conditions.

After leaving the BCI where did you go?
I am currently a Lecturer in Biomedical Engineering at Universidad Francisco de Vitoria in Madrid. I decided to return to my home country because I wanted to build my career and personal life closer to my family.

What are you currently working on and what do your future plans look like?
Within the Biomedical Engineering degree at UFV, I teach and conduct research related to the manufacturing and mechanical testing of biostructures such as splints, prostheses, and scaffolds. In the upcoming semester, I plan to supervise some final-year projects and gradually re-engage with research activities.

How did the BCI prepare you for work outside of academia?
One of the most valuable skills I developed at the BCI was the ability to communicate, present, and defend ideas effectively in front of an audience. This came from attending numerous international conferences thanks to the support of Professor Janice Barton, Professor Ole Thomsen, and the funding provided by CERTEST. I feel very proud of the professional I have become after completing my PhD at the BCI.

BCI develops composites manufacture simulation software: SimTex

Posted on 08/12/202508/12/2025 by jo.rich

SimTex is a fast simulation software developed at the BCI for composites manufacture. It contains modules for simulating 2D/3D weaving, braiding, filament winding and forming. SimTex can predict the as-manufactured component geometry and identify the onset of defects, thereby helping to enable right first time manufacture in prototyping of composites parts. It is currently deployed across a number of industry projects to support composites design for manufacture.

If you are interested to learn more about the SimTex software, please reach out directly to Stephen.Hallett@bristol.ac.uk.

InVIsion Carbon, an NCC Technology Pull-Through Project: In-process NDT for Higher Quality and Rate Automated Composites Manufacturing

Posted on 08/12/202508/12/2025 by jo.rich

Ege Arabul (BCI, University of Bristol), Per Saunders (Metrology, NCC), Robert Hughes (UNDT, University of Bristol)

As industries like aerospace, automotive, and renewable energy increasingly rely on high-performance carbon fibre composites, ensuring these materials are made perfectly – without defects – is more important than ever.

Current inspection methods mostly rely on visual checks or tests carried out after manufacturing is complete, when fixing problems is too late.

Our team at the Bristol Composites Institute (BCI), working with the National Composites Centre (NCC) and the Ultrasonics and NDT (UNDT) research group, has developed a new type of sensor that can spot issues during manufacturing, before the part is finished when remanufacture is more easily performed.

This Bi-directional Differential Eddy-Current Testing (ECT) Sensor uses the natural conductivity of carbon fibres to detect changes in how the fibres are laid down, revealing tiny gaps, overlaps, wrinkles, and other defects in real time.

We’ve successfully tested the sensor within the Hydrogen Tank and Automated Tape Laying manufacturing cells at the NCC, where it was able to identify and help correct defects as they appeared – saving time, reducing waste, and improving production quality.

This innovation marks a major step toward real-time, in-process inspection in composite manufacturing, cutting out costly post-production testing.

The work now continues within the FENDER project, where we’re inviting industry partners and researchers to join us in shaping the future of smart, automated composite manufacturing.

BCI speaker agenda – ICCM24

Posted on 04/08/202508/08/2025 by jo.rich

Bristol Composites Institute are attending this year’s ICCM24 in Baltimore, Maryland between 4-8 August.

Five people standing in a exhibition booth smiling at the camera — Members of BCI and NCC at ICCM24.

In partnership with NCC – Innovating for Industry, BCI will be on booth 208 in the Main Hall.

You can also watch the below technical presentations from BCI speakers across the week:

Monday 4^th August

4:30pm EDT, Room 309: Testing and Progressive Failure Modelling of a Wind Turbine Blade Spar Capweb Joint Substructure Dr Tobias Laux – University of Bristol.

Tuesday 5^th August

9:35am EDT, Exhibit Hall C: Welcome Remarks and Introductions to CerTest special session: Certification for Analysis Workshop, Prof Ole Thomsen – University of Bristol

9:55am EDT, Room 309: Effect of Clamping Force and Environmental Conditioning on the Mechanical Performance of Bolted Composite Laminates Dr Neha Chandarana – University of Bristol

10:10am EDT, Exhibit Hall C: Imaging Based Sub-Structure Testing and Data Fusion Methodologies for Integration of Virtual and Physical Data Prof Janice Barton, Prof Ole Thomsen – University of Bristol

4:10pm EDT, Exhibit Hall C: Wrap Up/Closing Comments Prof Ole Thomsen – University of Bristol

4:10pm EDT Poster Session: Development and Characterisation of Bamboo and Natural-Fibre Composite-Wrapped Tow-Reinforced Trusses
Poster Presenter: Matthew Lillywhite – Bristol Composites Institute. Authors: Benjamin Woods – University of Bristol, Byung Chul Kim – University of Bristol, Terence Macquart – University of Bristol

Wednesday 6^th August

9:35am EDT, Room 317: Is There a Hybrid Effect in Tensile and Compressive Failure of Carbon Fibre Composites Prof Michael Wisnom – University of Bristol

9:55am EDT, Room 318: Incorporation of High-Fidelity Experimental Data into Finite Element Models for Enhanced Comparison and Analysis Dr Meng Yi Song – University of Bristol

11:30am EDT, Room 319: Combined In-Situ Microscopy and Acoustic Emission Monitoring of Transverse Cracking in CFRP Cross-ply Laminates Mr Spyridon Spyridonidis – University of Bristol

2:45pm EDT, Room 319: Application of Infrared Imaging to Reveal Hidden Defects in CFRP Laminates Prof Janice Barton – University of Bristol

3:05pm EDT, Room 310: Characterisation of Embedded Channel Networks in CFRPs for Active Cooling Mr Toby Wilcox – University of Bristol

Thursday 7^th August

10:15am EDT, Room 317: Integration of Fuzzy Carbon Overbraids into Structural Members for Improved Compressive Performance Dr Laura Rhian Pickard – University of Bristol

11:00am EDT, Room 310: Programmable Shape Transformation in Multilayer Fiber Composites Through 4D Printing Mr Erdem Yildiz – University of Bristol

11:20am EDT, Room 319: The Effect of Optical Fibre CrossSectional Shape and Microstructure on Out of Plane Strain Sensitivity in Flexible Photonic Sensors Dr Robin Hartley – University of Bristol

3:05pm EDT, Room 317: he Experimental Investigation of the Compressive Performance of Pultruded Rod Composite Struts Dr Bohao Zhang – University of Bristol

Friday 8^th August

9:45am EDT, Room 317: Laminate Hybridization using High Modulus Carbon Thin Plies for Enhanced Compressive Performance Mr Yousef Rifai – University of Bristol

11:0am, Room 307: Differential Eddy Current Sensing Probe and It’s Implementation in Automated Composite Manufacturing Applications Mr Ege Arabul – University of Bristol

Freezing Failure: Understanding failure of composites at cryogenic temperatures

Posted on 28/07/2025 by jo.rich

by David Brearley

The advancements of magnets used in magnetic resonance imaging (MRI) have led to the incorporation of glass fibre reinforced polymer (GFRP) rings being adhesively bonded between epoxy-infused coils of superconducting wire. The two components respond differently to various loading conditions, potentially leading to structural failure. The magnet’s structure is integral to its’ performance as large electromagnetic forces (EMF) are induced due to the strong magnetic field present, under cryogenic temperatures. Unintentional quenches can be triggered by localised heat generated by friction or crack propagation. This results in Ohmic heating, boiling the surrounding liquid helium and potentially causing permanent, catastrophic damage to the magnet.

At the Bristol Composite Institute, the deformation and failure modes of an MRI magnet during operation were investigated by developing an experimental methodology for applying thermomechanical loads to test coupons, effectively mimicking MRI magnets in use. A simple finite element (FE) model of the magnet was constructed to assess the operational stress state and showed that high bi-axial stress concentrations were predicted around the adhesive bond between the coils and GFRP spaces.

To investigate how this could lead to structural failure, a Modified Arcan Fixture (MAF) as shown in Figure 1 was implemented. Several loading hole pairs were used to induce various compression-shear stress states in specimens that contained the adhesive joint cut from a full magnet. In the development of the experimental methodology, a more predictable bonded structure was manufactured using the coil infusion resin as an adhesive to simultaneously evaluate the epoxy’s isolated load response and refine the experiment. Tests were carried out at room and cryogenic temperatures so the thermomechanical load carrying capability of the bond could be evaluated.

Constant cryogenic cooling during quasi-static loading was achieved with the development of a novel modular cryostat that isolates the region around the adhesive bond from the rest of the fixture. The implementation of this cryostat facilitated the use of digital image correlation (DIC) to continually record the specimens’ full field response to the load at cryogenic temperatures, using just boiled pressurized nitrogen as the coolant. Based on a concept from NCC, a rapid prototyping approach was used to iteratively improve the design of the 3D printed cryostat, and in doing so, achieved test temperatures down to -150^oC while maintaining the necessary optical clarity.

Figure 1 – Schematic of the Modified Arcan Fixture (left) and the author conducting multi-axial tests with it (right).

This research has improved the understanding of how adhesive bonds, of a similar geometry to those found within an MRI magnet, respond to various bi-axial stress states at room and cryogenic temperatures, see Figure 2. The design process for the developed cryostat opens the door to countless potential possibilities for mechanical testing under cryogenic conditions, where complex thermomechanical stress states require advanced measurement techniques to evaluate the material’s load response.

Figure 2 – Load carrying capability of specimens containing the adhesive bond found within an MRI magnet (circles) and that of adhesively bonded steel plates (crosses, with yield profiles as dotted lines) at ambient (red) and cryogenic (blue) temperatures for various Modified Arcan Fixture load configurations: shear (α=90 ̊), compression-shear at a ratio of 1:2 (α=120 ̊), and of 2:1 (α=150 ̊ )

Composite Process Modelling to Fast-Track the Adoption of New Materials

Posted on 28/07/2025 by jo.rich

Fibre-reinforced composite manufacturing is highly sensitive to input variability (e.g., fluctuations in areal weight, tow misalignment, or inconsistent binder distribution) [1] which can lead to defects during preforming and subsequent steps. This sensitivity has long hindered the industrial deployment of process models, due to concerns over their predictive accuracy. However, recent work at BCI addresses this challenge by focusing on preforming process modelling, specifically how variations in the architecture and properties of dry textile reinforcements affect fabric deformation during forming. By embedding stochastic material descriptions into finite element forming models, we have demonstrated that it is possible to design robust forming processes that consistently deliver high-quality outcomes even when upstream variability is present [2]. This enables the definition of forming windows that are insensitive to material noise, thereby reducing defect rates and increasing confidence in preform quality. Crucially, one key conclusion from this work is that process models do not need to be perfectly accurate to support optimisation and that capturing the right trends is often enough.

This modelling philosophy becomes even more important when considering sustainable composite systems. In a recently completed PhD project focused on the processing of environmentally friendly materials (i.e., recycled carbon fibres and low-impact resins [3]) we demonstrated that upfront digital design accounting for manufacturing constraints, can significantly accelerate the development of viable processing conditions for new materials (see Figure 1). The same study also confirmed that recycled feedstocks tend to exhibit inherently higher variability. While this challenge remains unresolved for now, it is clear that the modelling strategies developed in the aforementioned study will be valuable here too.

The concept of using physics-based modelling not only to predict outcomes but to enable variability-aware process design will be advanced further in one of the workstreams of a recently announced EPSRC Prosperity Partnership. We strongly believe that wider industrial adoption of new composite systems (which is critical to deliver the net-zero agenda) will not be possible without a much greater reliance on process simulation. This, however, requires a paradigm shift whereby we stop chasing perfect models and start embrace “good enough” models [4].

References:

[1] Chen S., Talokder T., Mahadik Y., Thompson A. J., Hallett S. R. and Belnoue J. P.-H. (2025). Preform variability propagation in non-crimp fabric (NCF) forming, Composites Part B: Engineering, 299:112418, https://doi.org/10.1016/j.compositesb.2025.112418.

[2] Chen S., Thompson A. J., Dodwell T. J., Hallett S. R. and Belnoue J. P.-H. (2025). A comparison between robust design and digital twin approaches for Non-Crimp fabric (NCF) forming, Composites Part A: Applied Science and Manufacturing, 193:108864, https://doi.org/10.1016/j.compositesa.2025.108864.

[3] Yavuz B.O., Hamerton I., Longana M.L. and Belnoue J. P.-H. (2025). Modelling the tensile behaviour of aligned discontinuous carbon fibre thermoplastic matrix composites under processing conditions, Composites Science and Technology, 269:111252, https://doi.org/10.1016/j.compscitech.2025.111252.

[4] Belnoue J. P.-H. and Hallett S. R. (2024). Process models: A cornerstone to composites 4.0, Composites Part B: Engineering, 283:111621, https://doi.org/10.1016/j.compositesb.2024.111621.