Artikelaktionen

    Aktuelle Projekte

    Einige ausgewählte Forschungsprojekte, an welchen unser Team derzeit arbeitet:

    Thin-Walled Composite Structures with Improved Damping Properties by using Natural Fibre Composites and Thin Ply Carbon Fibre Technology (TwiCDamp)

    Weight reduction is a substantial driver to achieve higher energy efficiency in launching space structures such as satellites or measurement probes/telescopes. Typically, lightweight structures are however, prone to vibrations, leading to unwanted instability, reduced efficiency or in severe cases, structural failure. 

    This project studies the novel combination of natural fibre composites and thin ply carbon fibre composites to create extremely lightweight structures with supreme damping performance.

    Gewebe.jpg     Schliff.jpg

    Keywords: Thin ply composite, natural fibre composite, damping, microstructural vibration suppression

    High Performance Pultrusion of Carbon Fibre Reinforced PEEK (HPP)

    Ziel des Projektes ist es, die Qualität von pultrudierten Hochleistungs-Verbundwerkstoffprofilen (kohlefaserverstärktes PEEK) auf eine neue Qualitätsstufe zu heben. Dazu wird basierend auf einer eingehenden Materialcharakterisierung eine neuartige Pultrusionsanlage entwickelt. Im Prozess werden dabei die Toleranzen im Vormaterial sowie die Schwindung während Kristallisation und Glasübergang berücksichtigt und kompensiert.

     HPP.png

    Kristallstruktur von teilkristallinem PEEK in der Nähe von Kohlefasern (SEM Aufnahme) (Quelle: F: N. Cogswell,  Thermoplastic aromatic polymer composites. Oxford: Butterworth-Heinemann, 1992).

    Verwandte Themen: Thermoplastische Verbundwerkstoffe, Pultrusion, Prozesssimulation

    HICOMPLAST

    High performance composites with increased plasticity made from discontinuous carbon fibre tapes with thermoplastic matrix.

    Carbon fibre reinforced plastics (CFRPs) have outstanding strength and stiffness at low weight; however their failure tends to be sudden and catastrophic, which limits their application in safety critical applications. The aim of this project is to develop composites made from discontinuous CFRP tapes, which undergo large plastic deformation before failure, thus providing greater safety and reliability in critical applications

    HICOMPLAST teaser.png

    Discontinuous CFRP tapes.

    EU FP7 CERFAC - Joint reinforcement

    Cost Effective Reinforcement of Fastener Areas in Composites (CERFAC)

    A B-stage curing method had been developed to reinforce fasterner areas in an aircraft floor beam. The developed cure kinetic models, and effect of co curing on the bearing strength is investigated.

    Floor beam to omega frame connection in a fuselage, including reinforcement patches.

     

    Related topics: B-Stage Co-curing, Vario-therm Compression Resin Transfer Moulding, genetic optimisation algorithms, cure kinetics modelling, rheological modelling

     

    Website of the project

     

    EU FP7 CLEAN SKY JTI - Recycling

    The mission of this European project is to develop breakthrough technologies to significantly increase the environmental performances of airplanes and air transport, resulting in less noisy and more fuel efficient aircraft, hence bringing a key contribution in achieving the Single European Sky environmental objectives.

    Our institute is part of the Eco-Design cluster.
    Eco-Design will focus on green design and production, withdrawal, and recycling of aircraft, by optimal use of raw materials and energies thus improving the environmental impact of the whole products life cycle and accelerating compliance with the REACH directive.

    1. Composite plate 2. Fragmented plate 3. SEM

    Left: Composite plate; middle: high-voltage fragmented plate; right: SEM image of a fragment (133x)

     

    Related topics: Thermoset and Thermoplastic CFRP Recycling

    Cleansky_logo

    Website of the project

      

    High performance thermoplastic composites based on natural fibres  (CTI  project HIPETCONF)

    Flax fibres are a natural renewable resouce than can replace glass fibres in lightweight composite materials. These fibres are ideal for use with recyclable, tough, thermoplastic matrices. However, fibre wetting, interface compatibility and processing of these materials is complex, hence has seen restricted implementation.

    The technological objective of HIPETCONF is to develop high performance flax based composites with thermoplastic matrices for applications in lightweight structures. The case study is related to the sports & leisure industry, since it represents an ideal platform to launch novel material solutions, before transferring the developed technology to other markets.

    The approach in this project is to address challenges on three disciplinary levels of materials, processing and engineering, which are of course dependent on each other. In particular, our research focuses on:

    • Thermoplastic matrix selection according to flax fibres properties
    • Aid to fibre wetting and impregnation behaviour
    • Enhancing the matrix-to-fibre adhesion
    • Design engineering for high-performance composite parts
    • Industrial fast processing methods

     

    Related topics: natural fibres, flax, thermoplastic polymer, fast-processing, high-performance, sports & leisure industry, fibre-to-matrix adhesion, wetting behaviour

     

    Hybride Flachseile aus Carbon Composites (CTI project HyFaCC)

    Die Studie überprüft die Machbarkeit von flexiblen Flachseilen aus neuartigen Verbundwerkstoffen zur Kraftübertragung. Verschiedene Faser- und Matrixwerkstoffe werden untersucht. Berechnung, Herstellung und Spezifikation werden erarbeitet und durch Herstellung von Mustern anhand mechanischer Tests (statisch und dynamisch) verifiziert, um eine klare Aussage über die technische und ökonomische Machbarkeit zu treffen.

     hyfacc_01_flachseil.jpg

    Hybridisiertes Prepreg aus Kohle- und Dyneemafasern als mögliches Ausgangsmaterial zur Herstellung von Flachseilen (Quelle: North Sails 3Di)

     

    Related topics: carbon composites, hybridisation, fatigue

      

    Ortho Evolution 2015 - Innovation in Schuhkonzept und Stabilisierungssystem

    Die Firma Künzli SwissSchuh AG aus Windisch produziert und vermarktet seit Jahren erfolgreich orthopädische Stabilschuhe, die Künzli Ortho® Linie. Die Stabilschuhe werden zur Rehabilitation von Bänder-, Sehnen- und Knochenverletzungen am Fuss eingesetzt. Mittels einem Ortho® Stabilschuh wird die Mobilität erhalten und die Heilung der Verletzung aktiv durch kleine zugelassene Bewegungen unterstützt. Dem Patienten wird somit ein früherer Wiedereinstieg in den Berufsalltag ermöglicht.

    Der Künzli Stabilschuh ist ein etabliertes Hilfsmittel für die Heilung von Verletzungen im Fussbereich. Um dem zunehmenden Wettbewerb durch Hartplastikverbände und Orthesen zu begegnen, soll durch Kunststoff-Leichtbauprinzipien in Kombination mit modernsten Materialien und Design im Schuhbau eine Produktinnovation mit erweiterter Funktionalität realisiert werden, welche einen klaren Mehrwert in der Therapie generiert und sich langfristig am Markt etablieren wird.

     Ortho System.jpgOrtho Standard.jpg
     

    Das Ortho-System (links) und Ortho Standard Schuh (rechts) (Quelle: Künzli)

     

    Verwandte Themen: Orthopädie, Biomechanik

      

    Technical and economic assessment of Thin Ply Technology (CTI  project TECA), in high performance composites

    Thin Ply Technology offers unit plies four to six times thinner than conventional composites; by reducing ply thickness, one can gain improvements in the mechanical properties by reducing ply coupling, and having greater flexibility in ply angle and lay up. This opens a new range of high-end applications in aviation, space and sport.

    TECA_Bild1_small.jpgTECA_Bild2_small.jpg

    Optical cross sections of two carbon fibre epoxy thin ply laminate with aerial weight of 150 gsm (left) and 29 gsm (right), which is the minimum fibre areal weight of the tapes produced by Createx AG

    It is essential to scientifically characterise the benefits of the TPT to enable their application in high performance composite applications.

    Our research is

    • Developing of experimental validation of cure kinetics models and rheological models for the resins used in the material.
    • Optimising the out-of-autoclave production process ; determining the appropriate resin fraction in the pre-preg, optimised consumables and de-bulk pressure, time and temperature in order to achieve a excellent consolidation  in industrial production conditions.

     

    Related topics: Thin Ply Technology, prepreg development, vacuum processing of high performance materials, cure kinetics modelling, rheological modelling

     

    Multi Scale Composites

    The failure of a state of the art CFRP laminate is almost always governed by compressive failure in fibre direction (driven by the comparatively low matrix stiffness, resulting in buckling of single fibres at the microscopic level) or transverse strength (driven by the matrix strength at the fibre to matrix interface). Therefore, there has always been a high interest to enhance the properties of the fibre to matrix interface. One novel approach addressing those issues, referred to as multi scale composites (MSC), is to attach carbon nanotubes perpendicular to the surface of the carbon fibres and thereby reinforce the composite material both on the nano- and micro scale.

    The aim of this project is to understand the structure property relationship of these materials and to maximize the mechanical performance when used in CFRPs. This will be addressed in a first stage by improving the interfacial strength at a single fibre level. By upscaling to the lamina level, the CNTs from neighbouring fibres will interfere, leading to additional synergistic effects in increasing the mechanical properties of the MSC. However, additional challenges in impregnation have to be addressed within this second stage. The outcome of this project will help to substantiate the benefits of these materials for lightweight structures. Further it contributes to the understanding of the associated processing and impregnation issues for composite materials.

     

    Related topics: Multi Scale Composites, Carbon nanotubes

     

    Navigation
    Informationen für:
    Suchportlet