SIMulation of new manufacturing PROcesses for Composite Structures (SIMPROCS)

A particular aspect of polymer matrix composites is that in most cases the material structure is defined in the final stages of manufacture. This provides both advantages and challenges. Existing composites technologies are reaching maturity (e.g. Airbus A350 and Boeing 787), and new material forms are being developed to take further advantage of the opportunities that composites can offer (e.g. spatially varying properties, multi- functionality, light weight). The detailed material microstructure (e.g. final fibre paths, local fibre volume fraction and imperfections) is determined by the various processes involved in their manufacture. These details ultimately control the integrity of composite structures, however this information is not available at the early stages of conceptual design and stress analysis. This lack of suitable predictive tools means that the design of composite structures is often based on costly iterations of design, prototyping, testing and redesign.

This Platform Grant will help replace some of this empiricism with fully predictive analysis capabilities. A suite of advanced composite manufacturing simulation tools will be developed, and a dedicated team of experienced researchers will be established to sustain knowledge on new simulation capabilities for new and emerging manufacturing methods.

In parts made by Automated Fibre Placement (AFP) much of the tow path optimisation to improve part quality and production rate is done at the manufacturing stage. The research will develop numerical models that can accurately predict the as-manufactured geometry and fibre paths, making virtual manufacturing data available at a much earlier stage of design, ensuring parts are manufactured right-first-time with a minimum of defects.

For liquid moulding technologies, it is necessary to control the deformable fibre preforms during handling, deposition, draping, infusion or high pressure injection using stabilisation techniques. However, some of these technologies are not yet widely used due to the lack of suitable modelling tools. The team will build on their extensive understanding of the compaction and consolidation processes in composite precursors, complex preforms and prepregs to devise process simulation tools that will unlock the full potential of new liquid moulding technologies.

To maximise the reach of this research, the team will ensure that the simulation tools are suitable for future industrialisation. The software generated will be fully documented, optimised and robust, so that it can serve as a focal point for collaborative research with academia and industry on advanced process simulation techniques for composites.

In the longer term, hybrid preforms and aligned discontinuous fibre composites will be explored. Hybrid preforms incorporate tailored metallic inserts or reinforcements (e.g. produced via additive layer manufacturing). Such technologies can only be optimised if appropriate numerical tools are available for suitable multi-material process simulation. Aligned discontinuous fibre composites based on novel manufacturing methods require new constitutive models and process simulation tools so that their complex forming characteristics, thermal distortion and final microstructure can be accurately predicted to facilitate their adoption by different industries.

Working at the forefront of composites technologies, this Platform Grant stands in a highly advantageous position to step ahead of the current manufacturing paradigm, where modelling and understanding are at best catching up with the technology development, and pave the way for the manufacturing of tomorrow.

The growing demand for composites in the aerospace and other industries places increased attention on performance and the rates and repeatability of manufacture. Highly competitive markets and stringent regulations push forward the need for new technologies. However, the adoption of emerging concepts is largely impeded by a lack of confidence and understanding of the potential, flexibility and fundamentals of the underlying processes. This Platform Grant will focus on the gaps that are not currently covered by any current composite manufacturing or materials research programmes or by any other UK programmes. A link needs to be forged between Materials Manipulation and Structural Mechanics so that advantage can be taken of the emerging materials and process capabilities in novel advanced products.

The grant will create a platform for a faster uptake of new manufacturing processes by industry and reliable certification of novel approaches. Growing awareness in industry that "understanding means predicting" makes numerical simulations a crucial element in the certification process, particularly when it concerns developing capabilities. It becomes clear that emerging advanced technologies for new composite material configurations cannot be dealt with in a conventional pyramid of testing and materials allowables approach. The manufacturing of tomorrow will need to deal with overwhelming complexity in the physical behaviour of composite constituents, diversity of internal architectures, large variety of process solutions, and complex material and process hybridisation. Even though this Programme Grant is not aiming to develop these certification processes, it will deliver the critical bridging step between the materials and processes and the design communities. Focusing efforts on the simulation of manufacturing processes, it will be in a good position to deliver the structurally critical information on material meso-structures into a mechanical performance analysis framework. It must be emphasised that this is currently a significant gap that is not being addressed in other programmes and that unless it is tackled many of the current investments will not be able to reach their full potential.

The work in this grant will thus make a considerable contribution to UK manufacturing capability as well as in the long term lead to more efficient and achievable design solutions. This will accelerate the insertion of new composite material technologies into the aerospace and automotive industries at lower cost, thus contributing to growth in the economy and reduction of carbon emissions. A community of industrial end users (with whom the investigators already have a wide network of contacts) will be engaged to contribute to and support the technical activities undertaken within the grant, with a view to identifying exploitation opportunities.

Another particular aspect of the grant's impact will be on the staff involved. As this is a key skills shortage area, it will help with staff retention and provide critical mass for the support of other grant activity. It will also have a strong training and staff development element, particularly in commercialisation of early stage research.

In an academic context, the work will advance the state-of-the-art in composites manufacturing simulation, providing new techniques and algorithms as a foundation for future research. A targeted academic and industrial audience will be reached through international conferences such as the International and European Conferences on Composite Materials (ICCM and ECCM), SAMPE Conferences and ICMAC. The strong track record of the investigators, as evidenced by their high citation rates, ensures that the results will be published in top international journals, which will maximise coverage.