Digital Engineering of Space Composites

The aim of this project is to create a method to estimate the degradation of materials in hostile environments. Hostile conditions such as space or the deep sea make it difficult to actively monitor how a material or structure is performing. More accurate estimation of a material's life cycle in such conditions lead to more efficient designs that are better suited to the intended application.
The primary method used in this project will be to create a digital twin model for a number of composite laminates that are to be sent to the International Space Station (ISS) and exposed to space. The composite laminates will be sent to the ISS in April 2021 and then be exposed on the Bartolomeo platform for 6 months as part of a project with the European Space Agency (ESA). Following exposure, the samples will be returned to Earth where they will be reanalysed to quantify the effects of LEO exposure on the material. This information can then be used to update the computer model.
The computer model will be created using data collected through analysing sample laminates using a variety of imaging, thermal, and mechanical techniques such as optical microscopy, CT scanning, and mechanical testing. The data analysis and model building will be done in cooperation with the Jean Golding Institute which is involved in data science and data-intensive research at the University of Bristol.
Conditions in low earth orbit (LEO) such as those present around the ISS are very hostile, particularly to polymer materials like those in the matrix of fibre-matrix laminates. The hazard that will be focused on in this project is the presence of atomic oxygen from the upper atmosphere. This oxygen oxidises the surface of the materials in LEO, leading to erosion and loss of material which could lead to a loss in material performance. Other significant hazards in LEO are high-energy radiation and impacts by micrometeoroids. It may be possible do some ballistic testing to simulate impact and build this into the digital twin as well.
The matrix material used for this project is a novel polybenzoxazine polymer mixed with polyhedral oligomeric silsesquioxane (POSS). The benzoxazine polymer provides improved mechanical and thermal performance compared to standard aerospace epoxies while the addition of POSS has been shown through previous research to increase resistance to atomic oxygen erosion in polymeric materials.
Ultimately, it is hoped that this model could be used to add functionality or develop new materials for use on structures in low earth orbit. Later in the PhD project, once the digital twin model is complete, self-healing functionality will be added to the benzoxazine-POSS material using the Diels-Alder self-healing system.

There are seven principal groups of beneficiaries for our new EPSRC Centre for Doctoral Training in Composites Science, Engineering, and Manufacturing.

1. Collaborating companies and organisations, who will gain privileged access to the unique concentration of research training and skills available within the CDT, through active participation in doctoral research projects. In the Centre we will explore innovative ideas, in conjunction with industrial partners, international partners, and other associated groups (CLF, Catapults). Showcase events, such as our annual conference, will offer opportunities to a much broader spectrum of potentially collaborating companies and other organisations. The supporting companies will benefit from cross-sector learning opportunities and

- specific innovations within their sponsored project that make a significant impact on the company;
- increased collaboration with academia;
- the development of blue-skies and long-term research at a lowered risk.

2. Early-stage investors, who will gain access to commercial opportunities that have been validated through proof-of-concept, through our NCC-led technology pull-through programme.

3. Academics within Bristol, across a diverse range of disciplines, and at other universities associated with Bristol through the Manufacturing Hub, will benefit from collaborative research and exploitation opportunities in our CDT. International visits made possible by the Centre will undoubtedly lead to a wider spectrum of research training and exploitation collaborations.

4. Research students will establish their reputations as part of the CDT. Training and experiences within the Centre will increase their awareness of wider and contextually important issues, such as IP identification, commercialisation opportunities, and engagement with the public.

5. Students at the partner universities (SFI - Limerick) and other institutions, who will benefit from the collaborative training environment through the technologically relevant feedback from commercial stakeholder organisations.

6. The University of Bristol will enhance their international profile in composites. In addition to the immediate gains such as high quality academic publications and conference presentations during the course of the Centre, the University gains from the collaboration with industry that will continue long after the participants graduate. This is shown by the

a) Follow-on research activities in related areas.
b) Willingness of past graduates to:

i) Act as advocates for the CDT through our alumni association;
ii) Participate in the Advisory Board of our proposed CDT;
iii) Act as mentors to current doctoral students.

7. Citizens of the UK. We have identified key fields in composites science, engineering and manufacturing technology which are of current strategic importance to the country and will demonstrate the route by which these fields will impact our lives. Our current CDTs have shown considerable impact on industry (e.g. Rolls Royce). Our proposed centre will continue to give this benefit. We have built activities into the CDT programme to develop wider competences of the students in:

a) Communication - presentations, videos, journal paper, workshops;
b) Exploitation - business plans and exploitation routes for research;
c) Public Understanding - science ambassador, schools events, website.