26.2.1-R1 SELF ASSEMBLING HEALING AGENTS FOR MENDABLE EPOXY NETWORKS

F.JONES (THE UNIVERSITY OF SHEFFIELD), R.VARLEY, B.DAO, C.PILLSBURY, S.KALISTA

Self assembly of healing agents through ionomer formation for thermal self healing of epoxy resins is described. A relatively low MW DGEBA epoxy molecule,end-capped with ionomer functionality, achieved similar healing efficiencies to linear Phenoxy and high MW DGEBA polymers.

26.2.1-R2 TEST AND SIMULATION OF COMPOSITE SANDWICH STRUCTURE WITH A NOTCH UP TO FAILURE

O.MONTAGNIER (CREA - LMA - CNRS), JP.CHARLES, G.EYER, F.MAZEROLLE, N.LAHELLEC

It is proposed a new test on a large sandwich notched specimen. This test is used to validate a model based on damage mechanics and a nonlocal criterion. Numerical results compared to DIC show the efficiency of the proposed approach.

26.2.1-R3 MATRIX-FREE ALL CELLULOSE COMPOSITES

M.FORTEA (UNIVERSITÄT WIEN), KY.LEE, A.BISMARCK

Matrix – free all cellulose composites are produced by combining different types of cellulosic materials with vastly different sizes to produce high performance hierarchical composites, without the need for cellulose regeneration and, therefore, no chemical waste is produced.

26.2.1-R4 HIGH FIDELITY MULTIAXIAL TESTING OF COMPOSITE SUBSTRUCTURES

S.LAUSTSEN, E.LUND, L.KÜHLMEIER, OT.THOMSEN (UNIVERSITY OF SOUTHAMPTON)

A general methodology for high-fidelity experimental characterization of composite substructures subjected to multiaxial loading was developed. The response and failure behaviour of ‘grid-scored’ sandwich panels used in wind turbine blades was investigated. Simple criteria for failure prediction were proposed.

26.2.1-R5 MICROMECHANICAL ANALYSIS OF WOVEN COMPOSITES USING VARIATIONAL ASYMPTOTIC METHOD

R.NAIR, B.SIVASUBRAMONIAN, PJ.GURUPRASAD (IIT BOMBAY)

The aim of this work is to develop an efficient micromechanical model to obtain the mechanical properties of woven textile composites. Variational asymptotic method (VAM) is used as the mathematical framework for the homogenization procedure.

26.2.1-R6 A MODEL FOR THE PREDICTION OF FIBRE-MATRIX DEBOND INITIATION UNDER MULTIAXIAL STATIC LOAD

PA.CARRARO (UNIVERSITY OF PADOVA), M.QUARESIMIN

The Finite Fracture Mechanics approach is adopted to develop a model for predicting the initiation of a fibre-matrix debond crack under multiaxial loading. The model is validated with experimental results showing a sound agreement.

26.2.1-R7 COMPRESSIVE CHARACTERISTICS OF NOVEL CONTOUR CORE

AK.HALDAR (UNIVERSITY OF LIVERPOOL), WJ.CANTWELL, Z.GUAAN

An experimental investigation is presented into the compression response and subsequent failure modes in novel all-composite core parts based on a glass fiber reinforced plastic (GFRP) and a carbon fiber reinforced plastic (CFRP).

26.2.2-R1 DAMAGE MANIPULATION & REPAIR IN COMPOSITE T-JOINTS

J.CULLINAN (UNIVERSITY OF BRISTOL), MR.WISNOM, IP.BOND

Intrinsic repair of sub critical damage in CRT-joints has been demonstrated. Static and fatigue damage was successfully mitigated and infiltrated using embedded interleaves and vasculature respectively. In-situ repair of complex geometry mitigates the need for invasive repair strategies.

26.2.2-R2 HYSTERETIC SHEAR BEHAVIOUR OF FIBRE-REINFORCED COMPOSITE LAMINATES

M.MATEOS (MONDRAGON UNIBERTSITATEA), L.GORNET, P.ROZYCKI, L.ARETXABALETA

This work deals with hysteretic shear behaviour modelling of woven carbon fibre reinforced composites by using fractional derivative models. These models deal with history-dependent phenomena with a very few number of parameters. The model is able to reproduce hysteretic behaviour.

26.2.2-R3 CHARACTERISATION OF THE MECHANICAL AND INTERFACIAL ADHESION PERFORMANCE OF NATURAL FIBRES IN POLYOLEFIN COMPOUNDS FOR LIGHTWEIGHT AUTOMOTIVE APPLICATIONS.

JL.RUDEIROS (UNIVERSITY OF STRATHCLYDE), JL.THOMASON, M.SOLIMAN, AK.TARAIYA

This paper presents a study on the measurements of the interfacial adhesion of coir fibre with various polypropylene (PP) matrices (including a variation of coupling agent content) along with the mechanical properties of their related injection moulded composites.

26.2.2-R4 TRIBOLOGICAL BEHAVIOUR OF GRAPHITE FILLED POLYIMIDE COMPOSITES IN HYDROGEN ENVIRONMENT

G.THEILER (FEDERAL INSTITUTE FOR MATERIALS RESEARCH AND TESTING), T.GRADT

The tribological behaviour of graphite filled polyimide composites was investigated in air, hydrogen and vacuum conditions. Test results are discussed along with surface analyses. A particular attention is drawn to the influence of hydrogen on graphite and polymer structure.

26.2.2-R5 NUMERICAL PREDICTIONS OF THE NONLINEAR BEHAVIOR FOR BI-AXIAL BRAIDINGS

H.PETTERMANN (VIENNA UNIVERSITY OF TECHNOLOGY), J.GAGER

Carbon fiber braidings are investigated with respect to their mechanical behavior including various modes of damage and plasticity. Nonlinear Finite Element predictions are carried out up to laminate failure while monitoring the evolution of the material nonlinearities including softening.

26.2.2-R6 INITIATION OF FINITE CRACKS IN NON-POSITIVE GEOMETRIES

P.WEIßGRAEBER (TU DARMSTADT), S.HELL, W.BECKER

Finite Fracture Mechanics is used to study crack initiation at stress concentrations. In this work the effect of non-monotonic energy release rates on the solution of coupled stress and energy criteria is studied.

26.2.2-R7 MONITORING THE RESIDUAL STRAIN FORMATION IN CFRP/PMI FOAM CORE SANDWICH STRUCTURES

M.JOHN (FRAUNHOFER IWM), T.SKALA, R.SCHÄUBLE

Using foam core sandwich structures in commercial aviation a lot of advantages could provide. A disadvantage is the residual strain that is caused by the different properties of the sandwich components. The formation of residual strains was observed experimentally.

26.2.3-R1 TOUGHENING COMPOSITES WITH SELF-AMELIORATING CAPABILITY USING INKJET PRINTING TECHNIQUE

A.HODZIC (THE UNIVERSITY OF SHEFFIELD), Y.ZHANG, J.STRINGER, P.SMITH, R.GRAINGER

Poly(methyl methacrylate) ink was accurately deposited in a pre-defined microscopic hexagonal pattern onto carbon fibre prepreg substrate using an inkjet printing method before curing cycle, leading to a significant increase in damage tolerance and self-ameliorating capability of the composite system.

26.2.3-R2 FAILURE PREDICTION CAPABILITIES OF COMPOSITE FAILURE CRITERIA UNDER OUT-OF-PLANE LOADS

M.KOC, FO.SONMEZ (BOGAZICI UNIVERSITY), N.ERSOY, K.CINAR

In this study, failure behavior of fiber-reinforced composites under out-of-plane loads is investigated by means of four - point bending tests. Four – point bending tests are modeled analytically using the classical lamination theory (CLT) and numerically using FEM.

26.2.3-R3 BANANA AND ABACA REINFORCED POLYETHYLENE COMPOSITES MICROTENSILE VIDEO TESTS

Z.ORTEGA (UNIVERSIDAD DE LAS PALMAS DE GRAN CANARIA), M.MONZÓN, AN.BENÍTEZ, A.TCHARKHTCHI, S.FARZANEH

Microtensile video tests of banana and abaca reinforced composites obtained by rotomoulding. Differences between both types of fiber have been observed in the failure because of different compatibility of them with the PE matrix.

26.2.3-R4 IMPACT OF FIBERS DISTRIBUTION ON WATER ABSORPTION IN COMPOSITE MATERIALS: A MICROSCOPIC SCALE STUDY

T.PERET (IRT JULES VERNE), F.JACQUEMIN, S.FREOUR, A.CLEMENT

Two water diffusion models are studied. Fick and Langmuir models are compared through a numerical transient uncoupled hygro-elastic analysis. Effects of random fibers distribution on both water diffusion and mechanical states are discussed.

26.2.3-R5 STRENGTH ANALYSIS OF WOVEN INTERLOCK COMPOSITES SUBJECTED TO COMPRESSIVE LOADING: EXPERIMENTS AND SIMULATIONS

A.HURMANE (ONERA - UTC - MBD(SAFRAN)), FX.IRISARRI, F.LAURIN, S.LECLERCQ, M.BENZEGGAGH

This work aims at observing and modelling the behaviour, damage and failure of an interlock woven composite with polymer matrix under quasi-static tensile and compressive loads. The modelling is based on the Onera Damage Model for polymer matrix composites.

26.2.3-R6 CRACK ONSET AND PROPAGATION ALONG FIBRE-MATRIX ELASTIC-INTERFACES UNDER BIAXIAL LOADING USING FINITE FRACTURE MECHANICS

M.MUÑOZ-REJA (UNIVERSIDAD DE SEVILLA), L.TAVARA, V.MANTIČ, P.CORNETTI

Debond onset and propagation is analysed at a fibre-matrix interface subjected to remote biaxial transverse tension by a method based on the Linear Elastic-Brittle Interface Model and a coupled stress and energy criterion of the Finite Fracture Mechanics.

26.2.3-R7 FLEXURAL BEHAVIOUR OF GLASS FIBER REINFORCED ALUMINIUM HONEYCOMB SANDWICHES IN FLATWISE AND EDGEWISE POSITIONS

E.KARA (HITIT UNIVERSITY), V.CRUPI, G.EPASTO, E.GUGLIELMINO, H.AYKUL

The goal of this research was the analysis of edgewise bending response of sandwiches, which consists of aluminium honeycomb sandwich reinforced by outer skins made of glass fiber reinforced epoxy matrix.

26.2.4-R1 CLICK CHEMISTRY: TOWARDS SELF-HEALING POLYMER COMPOSITE

H.YUE (IMDEA MATERIALS INSTITUTE), JP.FERNÁNDEZ-BLÁZQUEZ, J.VILATELA

Click chemistry of thiol-alkyne photopolymerization as an effective self-healing agent system towards achieving self-healing ability in polymer composite was developed and showed a fast mechanical modulus increase as well as successful bleeding phenomenon confirmed by X-ray tomography.

26.2.4-R2 DETERMINATION OF THE TRUE STATISTICAL FLAW STRENGTH PARAMETERS FOR CERAMIC FIBRES FROM TESTS ON TOWS

J.LAMON (CNRS), M.R'MILI

26.2.4-R3 THERMAL STABILITY AND KINETIC STUDY OF THERMAL DEGRADATION OF A WOOD FLOUR-REINFORCED PHENOLIC FOAM

B.DEL SAZ-OROZCO, JC.DOMÍNGUEZ (COMPLUTENSE UNIVERSITY OF MADRID), M.OLIET, V.ALONSO, F.RODRÍGUEZ

Thermal stability of phenolic and wood flour-reinforced phenolic foams, and the wood flour employed as reinforcement were studied in this work by TGA and FTIR techniques. Kinetics of thermal degradation of both foams was studied by model-free kinetic methods

26.2.4-R4 INFLUENCE OF WATER ABSORPTION ON TEMPERATURE DEPENDENT STATIC STRENGTH OF UNIDIRECTIONAL CFRP

Y.YAMAKITA (KANAZAWA INSTITUTE OF TECHNOLOGY), M.NAKADA, Y.MIYANO

Two kinds of unidirectional CFRP (T300/epoxy and T700/vinylester) were treated under Dry and Wet conditions. The static strengths for typical four directions of these CFRP measured under various temperatures are discussed based on the viscoelasticity of matrix resin.

26.2.4-R5 DAMAGE MODELLING OF WOVEN COMPOSITES ON THE MICROSCALE AND MESOSCALE

E.OBERT (ENS-CACHAN), F.DAGHIA, P.LADEVÈZE, A.BERGEROT

This work extends the micro-meso bridge, previously developed for unidirectional laminates, to woven composites. The cracks kinetics is simulated at the microscale and homogenization relations are introduced to develop a mesoscale model.

26.2.4-R6 APPLICATION OF FINITE FRACTURE MECHANICS TO COMPOSITES: CRACK ONSET IN A STRETCHED OPEN HOLE POLYMER PLATE WITH NONLINEAR BEHAVIOUR

A.LEITE (UNIVERSITY OF SEVILLE / ISEL-IPL), V.MANTIČ, F.PARÍS

Fracture of stretched open-hole polymer plates is addressed by the coupled stress-energy criterion of Finite Fracture Mechanics using FEM simulations for linear/non linear elastic material models. Predictions of the size-effect on the critical load obtained are compared with experimental results.

26.2.4-R7 DETERMINATION OF THE CHARACTERISTICS OF A SANDWICH STRUCTURE WITH COMPLEX 3D SHAPE

B.BUFFEL (UNIVERSITY OF LEUVEN), F.DESPLENTERE, K.BRACKE, I.VERPOEST

Skin thickness, stiffness and foam core stiffness of a new type of in-situ formed sandwich structure were determined through different experimental set-ups including CT-based image processing. A tool was developed to predict the bending stiffness of the sandwich structure.

26.2.5-R1 SELF-HEALING OF FIBRE REINFORCED THERMOSET COMPOSITES BASED ON COMPARTMENTED FIBRES CONTAINING LIQUID HEALING AGENTS

W.POST (TU DELFT), S.GARCÍA, S.VAN DER ZWAAG

Self-healing in fibre reinforced thermoset composites is realised by incorporating fibres with discrete vacuoles filled with healing agent. Results show the partial recovery of mechanical properties and the presence of multiple local healing events in the same specimen.

26.2.5-R2 DAMAGE-PROPERTY CORRELATION AFTER LASER CUTTING OF CFRP

W.VON BESTENBOSTEL (AIRBUS GROUP INNOVATIONS), M.KOLB, A.FÜRST, A.WETZIG

Laser cutting realises high cutting rates of CFRP. The paper presents parameter studies influencing cutting quality determined by analytics of degradation morphologies. Optimised parameters were proved by mechanical testing. The results reveal the correlation between degradation and mechanical properties.

26.2.5-R3 INVESTIGATION OF HUMIDITY AGEING MECHANISM OF HEMP FIBER REINFORCED POLYPROPYLENE COMPOSITES

H.HAN (UNIVERSITY OF TECHNOLOGY OF TROYES), XL.GONG

Humidity ageing of hemp fiber reinforced polypropylene composites shows that the absorbed water causes fiber/matrix interface degradation. Stronger interfacial adhesion effectively retard the decrease of composites mechanical properties and improve the dimension stability by inhibiting water absorption behaviour of composites.

26.2.5-R7 EFFECT OF BLANK HOLDER FORCE ON DRAW FORMING OF STEEL/SRPP FIBRE METAL LAMINATE

J.NAM (AUSTRALIAN NATIONL UNIVERSITY), WJ.CANTWELL, R.DAS, A.LOWE, S.KALYANASUNDARAM

This paper presents findings on stamp forming and subsequent wrinkling behaviours of fibre metal laminate system based on steel and self-reinforced polypropylene. Blank holder force is varied at room temperature and forming limit diagrams are constructed from surface strain measurements.