Dynamic behaviour of composite materials for next generation aeroengines

Project Information

DYNACOMP

Grant agreement ID: 722096

DOI

10.3030/722096

Project closed

EC signature date 6 July 2016

Start date 1 September 2016

End date 31 August 2020

Funded under

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Total cost

€ 495 745,92

EU contribution

€ 495 745,92

Coordinated by

FUNDACION IMDEA MATERIALES
Spain

Periodic Reporting for period 2 - DYNACOMP (Dynamic behaviour of composite materials for next generation aeroengines)

Reporting period: 2018-09-01 to 2020-08-31

Summary of the context and overall objectives of the project

Composite materials are widely used nowadays in aeronautical structures because their good specific properties contribute to substantial weight savings and reduced fuel consumption. However, they are rarely used in components subjected to dynamic loads because our understanding of their structural behavior at high strain rates is still limited. DYNACOMP’s main scientific objective was to advance in this field, with the final technological objective of providing the means of developing novel and lighter materials with superior dynamic behavior for applications such as turbo-engines. This will require the use of a new generation of carbon fabrics and more specifically, new polymer resins. However, the current approach to introduce new composite materials in the aeronautical sector uses an extensive and costly experimental campaign based on a trial and error approach. A new design paradigm was thus needed, to reduce cost and lead time in design. DYNACOMP aimed at closing this gap by the development of a consistent, physically based, and multiscale simulation strategy for the analysis of the dynamic and impact behavior of the next generation of composite materials. The proposed simulation strategy describes systematically the material behavior at different length scales from ply/tow to laminate and to component level accounting for strain rate effects. One additional advantage of this bottom-up multiscale approach is that changes in the properties of the constituents (fiber, matrices), the fiber architecture or laminate lay-up can be easily incorporated to provide new predictions of the macroscopic behavior of the composite under impact. As a result of this action, a wide range of mechanical testing techniques capable of interrogating the mechanical behavior of composites at different length scales, from micrometers to millimeters, and at different strain rates, from quasi-static to dynamic conditions, has been developed. These tests have used to determine the mechanical properties of composite constituents (fiber, matrix and interfaces) as a function of strain rate, and these properties fed into multiscale simulations to predict the mechanical behavior of composite coupons under dynamic conditions. These novel experimental and simulation tools, developed in the context of an International Training Network with extensive participation of non-academic partners, will contribute to a new knowledge-based design paradigm that can speed up the introduction of better composite materials tailored for dynamic applications by the European composite industry.

To find out more, check this video: https://www.youtube.com/watch?v=9OgGmHvqWAM&feature=youtu.be.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

For the establishment of the new design paradigm, an intense experimental and numerical campaign was designed based on three composite materials: IM7/8552, IM7/M91, and WB1010/RTM250. The first two are carbon fiber prepreg systems with a second-generation (8552) and third-generation (M91) epoxy resin, the second containing toughening thermoplastic particles. The third one is a carbon fabric system suitable for RTM processing with a new generation epoxy-based low viscosity resin. DYNACOMP has fulfilled the following objectives:

- The development of novel experimental micro-mechanical characterization techniques, non-existent up to now, for the measurement of the constituent properties, fiber, matrix, and fiber/matrix interface, at high strain rates
- The incorporation of the constitutive behavior determined by the novel micromechanical testing techniques as inputs in advanced multiscale models
- The development of computational multiscale models to predict the strain rate dependent behavior of composite coupons under different loading modes. The outcomes of these simulations have been correlated with the outputs of a vast experimental campaign performed in the three composite systems under study.

The activities carried out have been widely disseminated through:

- The Project webpage: http://dynacomp-project.eu.
- 3 scientific papers in the best academic journals in the field. All publications are open access and copies are available in public repositories (Zenodo, Arxive). 3 more papers are under preparation
- Participation in 7 international scientific conferences
- Organization of 1 Summer School and a final online workshop with >100 attendees
- Several wide dissemination activities to general audiences, including news in social media, in mass media, participation in School visits, Science Fair’s and European’s Research night.
- A project video with the major outcomes and implications of DYNACOMP: https://www.youtube.com/watch?v=9OgGmHvqWAM&feature=youtu.be.

Finally, a number of exploitable results have been identified and the partners are actively looking for paths to bring some of them to market:

- New micromechanical testing methodologies at impact velocities
- New material models for high strain rates
- New matrix formulations for carbon fiber reinforced composites optimized for impact applications
- New certification procedures based on virtual testing
- New mechanical testing methodologies for testing composite coupons at high strain rates
- New methods for damage quantification in composite coupons by X-Ray tomography

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The main socio-economic impact of the DYNACOMP project is the establishment of a new design paradigm, based on physically based multiscale simulation strategies to reduce cost and lead time in the introduction of the next generation of composite materials in applications where the dynamic and impact behavior is important, such as fan blade manufacturing. The use of composite materials in aircrafts has the potential of contributing towards reducing the environmental footprint of the aeronautical sector. New, eco-efficient aircrafts are challenged by a demand to significantly reduce CO2 and NOx emissions, and one way to reduce environmental footprint is by the reduction of structural weight. As a result, Fibre-Reinforced Polymers (FRP) are nowadays extensively used in applications where outstanding mechanical properties are necessary in combination with weight savings. Good examples can be found in the A350 or the B787 Dreamliner, containing up to 50% in weight of composite materials used for wings, fuselage sections, and tail surfaces. However, the use of composite materials in other parts of the aircraft, such as turbo engines, is still very limited, even though the increase in efficiency that could be potentially accomplished by the replacement of traditional metallic alloys by means of lighter composite materials is tremendous.

On top of the socio-economic and societal implications, the DYNACOMP project has set up the grounds for a European Industrial Doctorate (EID) program between IMDEA Materials Institute, the Polytechnic University of Madrid, and Hexcel Composites Ltd. In the framework of this EID, early-stage researchers have received multidisciplinary and intersectorial training in the area of structural composite materials, including not only technical training, but also training on transferable skills, such as communication, innovation, and management. The PhD program will survive beyond the lifetime of the project, as new PhD students have already enrolled in areas related to Dynacomp and with the participation of the industrial partners.

The program has organized a Summer School on the topic and an industrial workshop to disseminate the outcomes.

Design paradigm proposed in DYNACOMP based on experimentally informed multiscale simulation strategy