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Research & Development Request

Aerospace composite companies sought for Eureka multilateral advanced materials call partner search for 4D x-ray visualisation of porosity within thermoplastic and thermoset composite materials in compression moulding.

Country of Origin: United Kingdom
Reference Number: RDUK20200430001
Publication Date: 30 April 2020

Summary

A Midlands based UK University is seeking partners to join their consortium for the Eureka Multilateral Advanced Materials call.  They are specifically interested in the utilisation of 4D x-ray visualisation to build an understanding of the sources of material inconsistency and failure. The are looking for aerospace composite companies that are interested in building aircraft structures from PEEK (Polyetheretherketone) and/or carbon fibre.

Description

The UK University is interested in the definition and recording of an approach/process by which CT (computed tomography) scanning and analysis can be used to evaluate the time-dependent, 4D, development of in-process porosity of a composite structure during compression moulding. 



Enhanced characterisation of the nucleation and evolution of defects is critical to predicting structural integrity of the composite. A resolution of 1µm has been demonstrated appropriate to capture both primary damage events and key local events enabling multi-scale characterisation of damage mechanisms.



This research is industrially relevant because the degree of porosity and associated crack propagation within a composite structure influences its mechanical properties, in particular its fatigue strength/performance. Composite materials, thermoplastics and thermosets) are used extensively within aircraft. By far the most significant advantage of composite materials is the potential for tailored anisotropic properties meaning a structure can be as strong and stiff as necessary whilst benefitting from improved structural weight and ultimately improved fuel efficiency. 



This is particularly relevant as the International Civil Aviation Organization (ICAO) has set the objective of maintaining global net CO2 emissions at 2020 levels through 'carbon neutral growth' and through compensation of emission growth above 2020 levels. 



The University's investigation will focus on Poly-Ether-Ether-Ketone (PEEK) and Poly-Aryl-Ether-Ketone (PAEK) in sheet form, reinforced with carbon fibres specifically for aerospace application. The emergence of automated layup procedures, notably within the aerospace sector combined with novel fibre-deposition configurations are enabling far greater design freedoms; however, the process of porosity depletion over time, associated morphology and distribution require further study. 



This inconsistency in the mechanical performance of composite structures results in unreliable and unpredictable performance in service. This is not acceptable for safety critical applications and limits the adoption of composite structures within aircraft applications despite the materials outperforming aluminium alloys in respect of: weight, corrosion resistance, fire retardation and ease of joining. 



While acknowledging that there may be a number of potential causes for the variation in mechanical performance of composite structures, this study is exclusively concerned with one factor: the degree of porosity present within the composite material during the compression moulding process; subcategorised to porosity morphology and distribution. 



It is widely accepted that the greater the porosity, the lower the fatigue strength, due to associated damage micro mechanisms. 



The development and optimisation of metrological approaches that enable non-destructive evaluation of composite structures during and post-process are seen as vital. The dependent variable in this study is defined as in-process porosity measured by volume. It is hypothesized that the degree of in-process porosity during compression moulding is influenced by at least four-parameters: process temperatures, temperature profile, pressure profile and material chemistry. 



These are the independent variables. Pressure is an important consideration but will be maintained constant in initial phases of the study pending development of effective research methods. 



Funding is sought to enable research into a process/approach that exploits this advance in technology for metrology purposes.



The university is looking for aerospace composite companies that can help build and test aircraft wing structures from PEEK (polyetheretherketone) and/or carbon fibre materials.



Expressions of Interest Deadline: 5th June 2020

Call Deadline: 30th June 2020

Advantages and Innovations

The use of CT scanning as a metrological approach to analysing the porosity of composite materials is established. 



The novelty provided by the proposed study relates to the live quantification (in-process evaluation) of the porosity of thermoplastic and thermoset materials during the compression moulding process. 



The capacity to perform this type of metrology has previously been limited because compact loading devices capable of being situated within x-ray CT scanners were not available. The development of these devices has enabled almost unobstructed imaging of the sample needed for rapid imagining. 



Furthermore, X-ray CT systems with fast acquisition detectors and data transfer have facilitated continuous streaming (up to 20 tomograms per second), so processes can be captured in real-time.

Expertise sought

Areas of expertise sought would ideally be from aerospace and advanced material companies that can help with:  



- Research into a process/approach that exploits this advance in technology for metrology purposes.



- Pressure testing.



- To build PEEK (Polyetheretherketone) structures - aircraft wings.



- Building Carbon Fibre structures - aircraft wings.



- Collections and gathering of data to show results.



And research in to the ongoing novel characterisation of composite manufacturing technique and they would like to have an industrial partner to be an end user for this Data.

Stage Of Development

Concept stage

Stage Of Development Comment

The research objectives are as follows:



1 - By July 2021, to have established CT Scanning and analysis methods for in-process evaluation on the effects of process temperature, temperature profile and material chemistry on the porosity within a composite structure (measured as a volume cubic millimetres) during compression moulding.



2 - By September 2022, to have defined and recorded the approach/process by which CT scanning and analysis can be used to evaluate the in-process development of porosity of a composite structure during compression moulding.



3 - By September 2023, to have gathered preliminary data relating to the effects of three independent variables: process temperature, temperature profile and material chemistry on the in-process quantification of porosity within a composite structure.



The University's current research has taken them to TRL 2 where the principles of in-process evaluation of porosity using CT scanning are demonstrated through experimentation. 



This feasibility study will move them towards TRL 3 where early proof of concept is demonstrated in the lab.

Requested partner

Types:

- Advanced Materials,

- Aerospace,

- Light Weight Composite Materials,

- Carbon Fibre and PEEK moulding companies, 



Role:

- Building aircraft wing structures,

- Testing,

- Recording data and results,

- Pressure testing,



Also research in to the ongoing novel characterisation of composite manufacturing technique so ideally they would also like to have an industrial partner to have the role as the end user for this data collection.