BEDR Accomplishment

November 11th, 2008

The Evaluation Board for ESA's Education “Fly your Thesis!” announced us that our project “Polymeric Composite Processing and Repair” was selected for the first phase of the Zero G program.

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Fly Your Thesis Workshop in Cologne, Germany - 2-3 Dec

After our acceptence to the first phase of the program, we will now attend a 2 day workshop at the European Astronaut Centre in Köln (Cologne), Germany. At this workshop the twenty selected teams from the first phase will present their scientific proposals, which will be evaluated by a committee and 3 or 4 projects will be accepted for the final phase, which is the zero gravity parabolic flight. More information concerning the project can be found on the European Space Agency website.

Micro-Nano-Macro(MNM) Cellular structures

The quest for lighter but stronger composites for use in aviation is a never ending one. With the increase in fuel prices, we can expect increased pressure for the development and use of lighter structural materials. One way of achieving this goal is to induce porosity into the system without sacrificing strength and stiffness. For many years, honeycomb construction has been a key to making lightweight efficient sandwich structures. Our work over the past four years has demonstrated that controlled induced porosity, especially at the nano-scale, where it is likely connected to the free volume of the polymer matrix, can potentially have a major impact. Furthermore, although several carbon fiber manufactures report limited success with inducing porosity within the fibers, primarily due to consistency and reproducibility, our work demonstrated that inducing porosity may offer a systemic approach for manufacturing light weight carbon fiber reinforced polymer (“CFRP”) matrix composites. Accordingly, because of their promise in these areas, we are trying to establish the fundamentals for creating the next generation of light weight structural composites by introducing porosity in a systemic and reproducible manner at the macro-micro and nano-scales.

Our focus is to create a unique framework for creating the next generation composite technology that is 40% lighter, while maintaining its load bearing structure characteristics such as stiffness and strength. Although the introduction of continuous fiber reinforced composites promised a nominal 40% reduction in weight over aluminium, its inherent anisotropy and heterogeneity reduced the effectiveness to less than 20%. However, the introduction of porosity in continues fiber reinforced composites promises similar game changing potential, even though the special location and structure of porosity and its transparency to the environment, such as open pores versus closed pores, promises similar challenges. Nonetheless, even if only a 20% further reduction in weight is achieved by controlling porosity at different scales (macro, micro, and nano), it may be viewed as the only way for CFRPs to achieve their full potential of producing the promised 40% weight reduction over traditional aluminium structures. At the moment, no one can refute that for the past 30+ years, we have been caught in a paradigm where design of load bearing structures in commercial and military aircraft has been that of “black aluminium,” that is, no order of magnitude changes over aluminium have been realized.

Carbon Fiber Recycling

The recycling of the polymeric composite materials that are used more and more to aerospace and other applications is a very critical issue. More than 60% of Boeing 787 material is carbon fiber reinforced composite and this material needs to be recycled when the aircraft bodies will be scrap in some years after the manufacturing. The degradation of the properties of the carbon fibers as they go through several generations of recycling and as a result their suitability for being used as primary material to new applications are some fields that need to be investigated.

Nanoengineered Carbon Fiber Composites Reinforced with In-situ Grown Carbon NanoTubes

This is an ongoing project we have in collaboration with professor Wardle and his team at MIT.

    Related Publications:
  1. Ishiguro, K., Sangari, S.S., Seferis, J.C. “Microcrack Initiation Mechanism of CFRP Under theThermal Cycle”, SAMPE Spring Tech. Conf. 2006 (2006).
  2. Timmerman, J.F., Hayes, B.S. and Seferis, J.C. “Cryogenic Microcracking of Carbon Fiber/Epoxy Composites: Influences of Fiber/Matrix Adhesion”, J. Composite Mat’ls, 3(21), 1939-1950 (2003).

More information and publication related to In situ grown CNTs in composites can be found to

Epoxy Foams

    Related Publications:
  1. Ishiguro, K., Sangari, S. S., Seferis, J. C. "The Influence on Mechanical Properties of Epoxy Foam Matrix Structural Differentiations", SAMPE Tech.l Conf. (2005).
    download [pdf, 248kB]
  2. Ishiguro, K. Karaki, T. Sangari, S.S. and Seferis, J.C., “Morphological and Mechanical Properties of Epoxy Foam Reinforced Composites”, SPE ANTEC (2005).
    download [pdf, 227kB]

Polynanomeric Composite Technology

    Related Publications:
  1. Lu, L. Sangari, S. S., Seferis, J. C. “Effects of Processing and Interface Morphology on Carbon Fiber Modified Interlayer Toughened Polynanomatrix Composites”, SAMPE Tech.Conf. (2005).
  2. Karaki, T., Killgore, J., Sangari, S. S., Seferis, J.C. “The Effect of Nano-Scale Particles Modification on Fatigue Behavior of Polynanomeric Matrix Composites”, Polymer Composites (2004) submitted.

Interlayer Toughened Hybrid Matrices

    Related Publications:
  1. V. M. Drakonakis, K Ishiguro, C.N. Velisaris, J. C. Seferis and G. C. Papanicolaou “Layered Hybrid Matrices for Carbon Fiber Reinforced Composites”, SAMPE Tech. Conf. (2008).
    download [pdf, 243kB]
  2. Gilbert, E.N., Hayes, B. S. and Seferis, J.C. “Interlayer Toughened Unidirectional Carbon Prepreg Systems: Effect of Preformed Particle Morphology”, Composites Part A: Applied Science and Manufacturing, 34 (3), 245-252 (2003).
  3. Zeng, S., Hoisington, M.A. and Seferis, J.C. "Particulate Interlayer Toughening of Dicyanate Matrix Composites", Polymer Composites, 14 (6), 458-466 (1993).

Carbon Carbon Composites

    Related Publications:
  1. V. M. Drakonakis and James C. Seferis,B. Wardle,J-D. Nam, G. C. Papanicolaou "Kinetic Viscoelasticity Modelling Applied to Degradation during Carbon Carbon Composite Processing", International Astronautical Conference (IAC) 2008
    download [pdf, 482kB]
  2. Nam, J.-D. and Seferis, J.C. “Initial Polymer Degradation as a Process in the Manufacture of Carbon/Carbon Composite”, Carbon, 30 (5), 751-761 (1992).