23.3.1-R1 PREDICTION OF OUT-OF-PLANE FAILURE MODES IN CFRP

R.PINTO (INEGI), P.CAMANHO

A study on the behavior of CFRP laminates bolted joints under transverse loading was conducted experimentally and numerically. A finite element model was developed to examine joint stress and predict onset of damage. Numerical and experimental results are in agreement.

23.3.1-R2 INTER AND INTRA-PLY SHEARING OF UNCURED CARBON FIBRE LAMINATES

S.ERLAND (UNIVERSITY OF BATH), T.DODWELL, R.BUTLER

Shear tests for uncured AS4/8552 are compared to a one-dimensional elastic-plastic model combining intra-ply shear and inter-ply slip. A new parameter joint strength describes the contribution of resin. A methodology for determining optimal shear properties during manufacture is presented.

23.3.1-R3 THE EFFECT OF NICKEL COATING OF CARBON FIBRE ON THE INFILTRATION PRESSURE REQUIRED TO PRODUCE CARBON FIBRE REINFORCED ALUMINIUM

H.CONSTANTIN (UNIVERSITY OF NOTTINGHAM), A.KENNEDY, L.HARPER, M.JOHNSON, N.WARRIOR

To quantify the wetting behaviour of aluminium on nickel coated and uncoated carbon fibre, composite materials were fabricated by liquid metal infiltration. Results show that nickel coating significantly reduces the pressure required to fabricate these composites, due to improved wetting.

23.3.1-R4 COMPOUNDING AND SPINNING OF POLYPROPYLENE NANOCOMPOSITES WITH KAOLINITE

I.DABROWSKA (UNIVERSITY OF TRENTO), L.FAMBRI, M.BATISTELLA, JM.LOPEZ-CUESTA

Polypropylene fibers with different kaolinite amount were produced by melt-spinning and hot drawing process. The dispersion of nanoparticles enhanced the elastic modulus of PP and positively affected the stress at break. Moreover, kaolinite improved the crystallinity content and thermal stability.

23.3.1-R5 INVESTIGATING DAMAGE RESISTANCE OF HYBRID COMPOSITE-METALLIC STRUCTURES USING MULTI-SCALE COMPUTED TOMOGRAPHY

T.ALLEN (UNIVERSITY OF SOUTHAMPTON), A.SCOTT, W.HEPPLES, SM.SPEARING, P.REED et al.

Multi-scale computed tomography (CT) was used to investigate an industrial low-velocity impact protocol on hybrid composite-metallic structures. The results show the impact response to be a combination of fibre fracture, intra-laminar cracks, delamination and plastic deformation of the metallic component

23.3.1-R6 CHALLENGES IN DEVELOPING NYLON COMPOSITES COMMINGLED WITH DISCONTINUOUS RECYCLED CARBON FIBRE

K.WONG (THE UNIVERSITY OF NOTTINGHAM), T.TURNER, S.PICKERING

A composite material containing commingled nylon fibres and recycled carbon fibres was studied in this paper. A papermaking process was used to produce random non-woven and aligned commingled mats for compression moulding and their mechanical and interfacial properties were analysed.

23.3.1-R7 THERMOFORMING SIMULATION OF THERMOPLASTIC TEXTILE COMPOSITES

P.BOISSE (INSA LYON), P.WANG, N.HAMILA

Thermoforming CFRTP prepreg is a fast manufacturing process compared to LCM process or thermoset prepreg forming. In addition the composites with thermoplastic matrix are more easily recyclable than thermoset materials. A simulation approach for thermoforming of multilayer thermoplastic is presented.

23.3.2-R1 INFLUENCE OF AN OPTIMIZED 3D-REINFORCEMENT LAYOUT ON THE STRUCTURAL MECHANICS OF CO-BONDED CFRP JOINTS

M.JUERGENS (AIRBUS GROUP INNOVATIONS), AC.NOGUEIRA, H.LANG, E.HOMBERGSMEIER, K.DRECHSLER

Through-thickness reinforcement design for an efficient load transfer in structural CFRP/CFRP joints was advanced. Geometrical parameters of metallic 3D-reinforcements were varied and their impact on the mechanical joint properties was investigated through quasi static single-lap shear testing.

23.3.2-R2 NON-SYMMETRIC STACKING SEQUENCES TO AID MANUFACTURE

T.FLETCHER (UNIVERSITY OF BATH), R.BUTLER, T.DODWELL, S.ERLAND

An AFP laid C-section laminate with tapering thickness has been produced with a novel (non-symmetric) stacking sequence, alongside a baseline laminate with a symmetric stacking sequence. The novel laminate achieved better consolidation and reduced the level of warping during manufacture.

23.3.2-R3 PRODUCTION OF ALUMINUM-ALUMINUM NITRIDE NANO-COMPOSITES BY A GAS-LIQUID REACTION

M.MAKHLOUF (WPI), C.BORGONOVO

A method is developed for synthesizing aluminum-aluminum nitride nano-composite materials wherein nano-sized aluminum nitride particles are formed in-situ in a molten aluminum alloy. The method involves causing a reaction between a nitrogen-bearing gas and a specially designed molten aluminum alloy.

23.3.2-R4 MODELLING INTERACTION EFFECT OF NANOSILICA PARTICLES ON NANOSILICA/EPOXY COMPOSITE STIFFNESS

M.MULYADI (THE UNIVERSITY OF SHEFFIELD), I.GITMAN, C.PINNA, C.SOUTIS

Micromechanics-based analytical and numerical model were performed to predict elastic modulus of Nanopox F400/Epikote 828 composite. Results from the simulations are compared to measured data; a good correlation is achieved provided that the properties of the interphase are accurately represented.

23.3.2-R5 STRUCTURAL EFFICIENCY VIA MINIMISATION OF ELASTIC ENERGY IN DAMAGE TOLERANT LAMINATES

A.RHEAD (UNIVERSITY OF BATH), M.NIELSEN, R.BUTLER

An analytical method for selecting fibre orientations to minimise elastic energy, maximising structural efficiency, of damage tolerant laminates is presented. Optimised designs balance the demands of aligning fibres with applied loads and minimizing surface ply energy available for delamination propagation.

23.3.2-R6 A STEP CHANGE IN THE RECYCLING OF COMPOSITE MATERIALS

G.OLIVEUX (UNIVERSITY OF BIRMINGHAM), L.DANDY, GA.LEEKE

Our objective is to research and develop novel engineering technologies along with robust proven technologies to recycle composite materials. The aim is to establish green and cost effective strategies for the deconstruction, re-cycle and re-manufacture of composite material.

23.3.2-R7 MESO-SCALE MODELING OF DAMAGE IN TEXTILE COMPOSITES WITH COMPACTED AND NESTED REINFORCEMENTS

M.HIRSEKORN (ONERA), C.FAGIANO, A.DOITRAND, P.LAPEYRONNIE, V.CHIARUTTINI

Textile composites are modeled mechanically at the meso-scale, taking into account fabric preforming, layer shifts, and damage. Good agreement with experimental observations is found if the real specimens' layer shifts and micro-decohesions around transverse yarn crack tips are included.

23.3.3-R1 EXPERIMENTAL AND FINITE ELEMENT ANALYSIS OF BONDLINE FLAW CRITICALITY IN COMPOSITE SCARF JOINTS

J.KOSMANN (GERMAN AEROSPACE CENTRE (DLR) /AND/ COOPERATIVE RESEARCH CENTRE FOR ADVANCED COMPOSITE STRUCTURES), D.HOLZHÜTER, AJ.GUNNION, C.HÜHNE

The criticality of bondline flaws in scarf joints is analysed using finite element analysis. Experimental data is presented for various initial flaw sizes. The strength of a scarf joint is considerably and adversely affected by the presence of a flaw.

23.3.3-R2 A STUDY OF THE PRESSURE DISTRIBUTION IN THE HAND LAYUP AND VACUUM BAGGING PROCESSES

D.BLOOM (UNIVERSITY OF BRISTOL), MA.NAPPER, C.WARD, KD.POTTER

The bagging process, designed to remove air and aid consolidation is a further opportunity for introducing variability in manufacture. Using a pressure mapping system, common bagging defects like bridging are examined in the context of their effect on part quality.

23.3.3-R3 ANALYSIS OF STRENGTHENING MECHANISMS OF THE ALCU5MGTI ALLOY REINFORCED WITH TIB2 PARTICULATES

P.EGIZABAL (TECNALIA RESEARCH & INNOVATION), M.GARCIA DE CORTAZAR, A.TORREGARAY, JF.SILVAIN

The present study was devised to analyse the strengthening mechanisms of an AlCu5MgTi alloy reinforced with TiB2 particulates . The main strengthening mechanisms involved are related to the lower grain sizes of the reinforced alloys and lower degree of defects.

23.3.3-R4 PROCESSING BEHAVIOUR OF A NANOCOMPOSITE MATRIX FOR MULTISCALE COMPOSITES

Y.LIU (THE UNIVERSITY OF MANCHESTER), A.WILKINSON

The processability and dispersion of a multiwall carbon nanotubes (MWCNTs)/tri-functional epoxy resin nanocomposite matrix suitable for the preparation of carbon fibre composites was developed and investigated in terms of the curing behaviour, rheology and thermal mechanical properties.

23.3.3-R5 DIAMETRAL COMPRESSION TESTS OF A PULTRUDED PA6 REINFORCED GLASS FIBRE COMPOSITE: A MACRO AND MICRO TRANSVERSE DAMAGE KINETIC INVESTIGATION

H.CAYZAC, S.JOANNÈS (MINES-PARISTECH), L.LAIARINANDRASANA

The transverse behavior of a pultruded rod is characterized by diametral compression tests (triaxial loading within the material) and the damage kinetic is observed by tomography. A multi-mechanisms model is implemented to simulate this microstructural behavior.

23.3.3-R6 DEVELOPMENT OF HIGH-STRENGTH/LIGHTWEIGHT HEATING COMPOSITE BOARD MADE OF CARBON FIBER WASTE

K.HONJO, T.KIMURA (KYOTO INSTITUTE OF TECHNOLOGY), H.INO, K.SHIBATA, K.OSAKO

In concerning of superior mechanical properties and good electrical conductivity of carbon fiber, we try to mold the high-strength/lightweight heating composite board by extruding molding method. From the results, reinforcement effect of carbon fiber and heat generation function were confirmed.

23.3.3-R7 CONTINIOUS PRODUCTION OF BRAIDED PARTS WITH THERMOPLASTIC MATRICES

J.SCHÄFER (INSTITUT FÜR TEXTILTECHNIK (ITA) OF RWTH-AACHEN UNIVERSITY), N.HAWELKA, T.GRIES

Using thermoplastic matrices for the production of composites has several advantages e.g. shorter process time and the possibility to recycle the material. By combining the braiding with the hybrid yarn technology a pultrusion process for thermoplastic composite profiles is possible.

23.3.4-R1 DAMAGE-COUPLED MODELING FOR THE JOINING PROCESSES ANALYSIS OF COMPOSITE-TO-METAL JOINTS

J.MAO, S.NASSAR (OAKLAND UNIVERSITY)

Experimental and FEA techniques are used for investigating the load transfer capacity and associated failure modes for lightweight composite joints. The effect of three joining methods is demonstrated; namely, bonding-only, bolting-only, and hybrid bonding-and-bolting.

23.3.4-R2 ON THE INVESTIGATION OF RESIDUAL STRESS AND SHAPE DEVIATION DEVELOPMENT IN MANUFACTURING OF GLARE

M.ABOUHAMZEH (TECHNICAL UNIVERSITY OF DELFT), J.SINKE, R.BENEDICTUS

The Methodology is presented to predict the shape deviations and residual stresses after cure and post-cure of a fuselage panel made of Fibre metal laminates (FMLs). Results are presented from primary modelling and experiments and the needed improvements are described.

23.3.4-R3 INVESTIGATION ON THE STRENGTH DISTRIBUTION OF UNIDIRECTIONAL CERAMIC MATRIX MINI-COMPOSITES WITH POROUS MATRIX PHASE

R.HENNING (GERMAN AEROSPACE CENTER), M.BARTSCH, B.KANKA

The size-dependent strength properties of unidirectional oxide/oxide ceramic matrix minicomposites with porous matrix phase were investigated by performing tensile tests on specimens with different gauge lengths. Results were evaluated taking into account varying fibre volume content and defect population.

23.3.4-R4 EFFECT OF PROCESSING CONDITIONS ON MECHANICAL AND BARRIER PROPERTIES OF PLA/CLAY NANOCOMPOSITES

Y.NAKADE (DOSHISHA UNIVERSITY), Y.ARAO, T.TANAKA

Elongation, toughness and gas barrier can be improved by adding nanoclay in the PLA. The processing conditions of the twin-screw extruder determine the dispersions state of nanoclay in the matrix: hence affect the mechanical and barrier properties of PLA/clay nanocomposites.

23.3.4-R5 DAMAGE TOLERANCE OF COMPOSITE T-SECTIONS MADE OF COST-EFFECTIVE CARBON FIBRE PREFORM

M.KADLEC (VZLU), R.HRON, T.GRIESER

This work presents the structural response of cost-effective laminated T-sections when subjected to various types of loads and impacts. Pull-off, flange tension, and flange bending were tested for specimens extracted from an I-beam to assess the failure processes.

23.3.4-R6 THE DETERMINATION OF CARBON FIBRE BUNDLE SIZES BY ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY

L.DANDY (UNIVERSITY OF BIRMINGHAM), G.OLIVEUX, J.WOOD, MJ.JENKINS, GA.LEEKE

The determination of the number of Carbon Fibres in a bundle facilitating the tensile testing of fibre bundles, and thereby potentially alleviating the requirement for extensive single fibre testing.

23.3.4-R7 SIMULATION OF DAMAGE EVOLUTION IN A TEXTILE COMPOSITE DOUBLE-CANTILEVER BEAM

D.MOLLENHAUER (U.S. AIR FORCE RESEARCH LABORATORY), E.IARVE, E.ZHOU, T.BREITZMAN, K.HOOS et al.

Damage evolution in polymer matrix, textile composite, double-cantilever beam (DCB) specimens was simulated. The focus of the study was to examine the effects of tow nesting on the performance of DCB specimens with a single textile layer per adherend.