25.3.1-R1 DESIGN OF JOINTS OF COMPOSITE MEMBERS WITH CURVILINEAR REINFORCEMENT STRUCTURE

A.MALAKHOV (INSTITUTE OF MACHINES SCIENCE NAMED AFTER A.A.BLAGONRAVOV OF THE RUSSIAN ACADEMY OF SCIENCES), A.POLILOV

This paper describes a junction between a composite plate and a metal component as well as a method of modelling a heterogeneous composite structure with curvilinear reinforcement.

25.3.1-R2 MULTIAXIAL BEHAVIOR OF NOTCHED COMPOSITE STRUCTURES MANUFACTURED BY DIFFERENT PROCEDURES

JL.MARTINEZ VICENTE (UNIVERSIDAD DE CASTILLA-LA MANCHA), MC.SERNA, MA.CAMINERO, JJ.LÓPEZ

Composite structures materials have geometrical discontinuities due to different design reasons and develop multiaxial stress states under general loading conditions. In this work, experimental studies are performed in order to analyze the behavior of unnotched and notched composite laminates.

25.3.1-R3 CHARACTERIZATION OF UNIDIRECTIONAL DISCONTINUOUS BAMBOO FIBRE/EPOXY COMPOSITES

E.TRUJILLO (KATHOLIEKE UNIVERSITEIT LEUVEN), D.PERREMANS, L.OSORIO, AW.VAN VUURE, J.IVENS et al.

Unidirectional bamboo fiber epoxy composites with randomized bamboo fiber ends were produced and characterized throughout tensile tests. Strength and stiffness results demonstrated the influence of discontinuities in the final composite behavior.

25.3.1-R4 SHOCK PROPAGATION RESPONSE OF COMPOSITE LATTICE STRUCTURES

K.SHIMODE (UNIVERSITY OF TOKYO), T.YOKOZEKI, T.AOKI, K.TERASHIMA, T.KAMITA

Anisogrid composite lattice structure is a superior candidate as the lightweight aerospace structure, and it is also expected to have high wave attenuation properties owing to the nodal structure. Its shock propagation behavior is experimentally evaluated in this study.

25.3.1-R5 PULSE PHASE THERMOGRAPHY FOR KISSING DEFECT DETECTION

J.DULIEU-BARTON (UNIVERSITY OF SOUTHAMPTON), R.WAUGH, S.QUINN

An investigation into the application of pulse phase thermography (PPT) to identify kissing defects in adhesive bonds has been undertaken.

25.3.1-R6 PIEZO-RESISTIVITY OF TEXTILE COMPOSITES CONTAINING CARBON NANOTUBES AT LARGE DEFORMATION REGIME

WJ.NA (SEOUL NATIONAL UNIVERSITY), SY.JEON, WR.YU

Micro-damages of textile composites have been characterized using CNT networks and visualizing with X-ray CT, concluding that the sensitive observation of micro-cracks is accurate enough to identify the initiation and evolution of internal damages in textile composites.

25.3.1-R7 STRUCTURE-PROCESS-PROPERTY RELATIONSHIP OF CONDUCTIVE EXFOLIATED GRAPHITE NANOPLATELET / POLYLACTIC ACID FILMS

E.SULLIVAN (GEORGIA INSTITUTE OF TECHNOLOGY), YJ.OH, R.GERHARDT, B.WANG, K.KALAITZIDOU

Exfoliated graphite nanoplatelets/polylactic acid films were fabricated using melt compounding/compression molding and the effect of cooling rate was examined. Crystallinity and electrical conductivity increased with decreased cooling rate showing that properties can be tailored/engineered during processing for a materials system.

25.3.2-R1 COMPOSITE TO COMPOSITE JOINT WITH LIGHTWEIGHT METAL REINFORCEMENT FOR ENHANCED DAMAGE TOLERANCE

S.UCSNIK (LKR LEICHTMETALLKOMPETENZZENTRUM RANSHOFEN GMBH), S.STELZER, H.SEHRSCHÖN, G.SIEGLHUBER

This research presents two FRP joining concepts: “CMT pin” and “Sheet pin”. 3D reinforcement elements build up a fiber friendly form-fit with CFRPs. This work proves distinct increases of joint properties of “CMT pin” and “Sheet pin” joint CFRP components.

25.3.2-R2 A NEW METHODOLOGY FOR TESTING COMPOSITE MATERIALS IN MODE III OF FRACTURE

A.LOPEZ, J.VIÑA (UNIVERSITY OF OVIEDO), A.ARGÜELLES, J.BONHOMME, V.MOLLÓN et al.

This paper presents a new device for testing composite materials in mode III of fracture, which lets to test in mode III quasi-pure, because there is not practically mode II.

25.3.2-R3 A “MORPHOLOGICAL APPROACH” FOR MODELLING THE ELASTIC AND VISCOELASTIC PROPERTIES OF STRAND-BASED WOOD COMPOSITES: COMPARISON WITH OTHER RECENT ANALYTICAL AND NUMERICAL MODELS

S.MALEKMOHAMMADI, B.TRESSOU, C.NADOT-MARTIN (INSTITUT P', CNRS - UNIVERSITÉ DE POITIERS - ENSMA - UPR 3346, POITIERS, FRANCE), R.VAZIRI

Effective properties of a parallel strand lumber (PSL) unit cell are estimated thanks to a specific scale transition approach, called “Morphological approach” (MA). Results are successfully compared to finite element reference solutions, and are better than other estimates recently proposed.

25.3.2-R4 DESIGN OPTIMIZATION OF AN UNCONVENTIONAL CFRP AIRCRAFT PANEL STIFFENER BASED ON MANUFACTURABILITY CRITERIA OF INTEGRATED FIBER PLACEMENT PROCESS ANALYSIS

O.DENIZ (TECHNISCHE UNIVERSITÄT BRAUNSCHWEIG), P.HORST, P.WEBER, C.SCHMIDT, B.DENKENA

A multidisciplinary design optimization that automatically comprises structural analysis in conjunction with the manufacturability of unconventional aircraft panel components and restriction of imperfections such as tow gaps based on a newly developed AFP system is introduced.

25.3.2-R5 VISUALIZATION AND NDT EVALUATION OF LIGHTNING DAMAGE BEHAVIOR OF CFRP LAMINATE

Y.HIRANO (JAPAN AEROSPACE EXPLORATION AGENCY), H.KUSANO, T.SONEHARA

This paper examines the effect of shock wave associated with lightning on damage behavior of CFRP laminate with schliren photography technique. The influence of different discharge proves and surface LSP mesh on damage behavior is focused on.

25.3.2-R6 STRAIN MEASUREMENTS AND DAMAGE DETECTION IN LARGE COMPOSITE STRUCTURES BY FIBER OPTICS SENSORS

J.SIERRA (UNIVERSIDAD PONTIFICIA BOLIVARIANA), A.GÜEMES, M.GOMEZ

By means of a novel technique based in strain field pattern recognition, a study of detectability of defects was performed for a 14m wind turbine blade. Results showed that damages could be detected by using strains gathered from FBGs and distributed sensing.

25.3.2-R7 MEASUREMENT OF NANOPARTICLE DISTRIBUTION IN COMPOSITE LAMINATES PRODUCED BY RESIN TRANSFER MOLDING

B.LOUIS (ETH ZURICH), J.MALDONADO, F.KLUNKER, P.ERMANNI

In this study, composite laminates with a nanoparticle loaded matrix were produced by RTM and their particle distribution was measured, allowing the effect of process parameters to be evaluated. In general, a non-homogenous particle distribution was observed.

25.3.3-R1 EXPERIMENTS AND MODELLING OF CLAMPING EFFECTS ON THE BEARING STRENGTH OF MECHANICALLY FASTENED JOINT IN CFRP LAMINATES

FX.IRISARRI (ONERA), T.VANDELLOS, P.PAULMIER, F.LAURIN

An experimental investigation is performed on 16-ply carbon/epoxy laminates. Three stacking sequences are tested in pin-bearing and bolt-bearing conditions. Combined effect of the washer size and clamping load on the bearing strength are investigated. Numerical study will follow.

25.3.3-R2 SELECTION OF TEST METHODS TO EXAMINE THE FRACTURE MECHANICS OF CARBON FIBRE COMPOSITE FLYWHEELS

J.LENZ (IMPERIAL COLLEGE LONDON), B.BLACKMAN, A.TAYLOR, R.MORGAN, C.CRUA

This paper outlines a study that aims to induce failure in CFRP flywheels such that the consequences of failure can be assessed and the implications for flywheel containment can be better understood and presents the planned test program associated.

25.3.3-R3 FORMING ANALYSIS OF CHOPPED FLAX FIBRE REINFORCED POLYPROPYLENE COMPOSITES

W.WANG (AUSTRALIAN NATIONAL UNIVERSITY), A.LOWE, S.KALYANASUNDARAM

This work presents fundamental results on the research carried out by stamp forming of a chopped flax fibre reinforced polypropylene composite. The results obtained in this study provide insight into challenges facing stamp forming of this class of material systems.

25.3.3-R4 MICROMECHANICS OF COMPOSITE ANISOGRID STRUCTURES

G.TOTARO (CIRA - ITALIAN AEROSPACE RESEARCH CENTER), F.DE NICOLA, A.GRILLI, A.FERRIGNO, P.CARAMUTA

The possibility to modify the typical low fiber volumetric fraction in interlaced anisogrid structures is here preliminarily explored using a flat panel in which possible deviations from the baseline manufacturing process (dry tows, rubber tooling, and resin infusion) are tested.

25.3.3-R5 THERMOGRAPHIC NON-DESTRUCTIVE INSPECTIONS OF WIND TURBINE BLADES USING UNMANNED AERIAL SYSTEMS

C.GALLEGUILLOS, A.ZORRILLA, A.JIMÉNEZ, L.DIAZ, F.LASAGNI (CATEC) et al.

This work presents a feasibility study for defect detection in wind blades using Unmanned Aerial Systems (UASs). IRT inspections are performed first in a specimen located at ground level, and later during flight operation by UAS rotorcraft.

25.3.3-R6 OPTIMAL SELECTION OF PARAMETERS FOR IMPACT DAMAGE DETECTION IN COMPOSITES BASED ON NONLINEAR VIBRO-ACOUSTICS MODULATIONS

A.KLEPKA (AGH UNIVERSITY OF SCIENCE AND TECHNOLOGY), L.PIECZONKA, M.ADAMCZYK, W.STASZEWSKI, F.AYMERICH et al.

This paper demonstrates how to select frequencies of high-frequency ultrasonic excitation for vibro-acoustic modulatiom test. The results show that optimal selection of these parameters can enhance sensitivity of the method when used for damage detection.

25.3.3-R7 HIERARCHICAL AND HYBRID POLYMER NANOCOMPOSITES BASED ON CARBON NANOTUBES AND INORGANIC FULLERENE TYPE NANOPARTICLES

M.GÓMEZ-FATOU (CSIC), AM.DIEZ-PASCUAL, M.NAFFAKH, G.ELLIS, C.MARCO et al.

The influence of SWCNTs and inorganic fullerene-like nanoparticles on the morphology and thermal, mechanical and electrical performance of multifunctional fiber-reinforced polymer composites will be presented. Covalent and non-covalent strategies to efficiently incorporate SWCNTs in polymer matrices have been developed.

25.3.4-R1 ON THE EFFECT OF PRE-BOND MOISTURE IN THE ADHERENTS ON THE FRACTURE TOUGHNESS OF BONDED JOINTS FOR REPAIR PURPOSES

A.RODRÍGUEZ-BELLIDO (AIRBUS OPERATIONS, S.L.), S.BUDHE, J.RENART, J.COSTA

The sensitivity to pre-bond moisture of two adhesive films has been evaluated in co-bonded joints for composite repairs. Pre-bond moisture produced a dramatic effect on the fracture toughness values and on the failure mode

25.3.4-R2 PROGRESSIVE DAMAGE ANALYSIS OF NCF COMPOSITES UNDER COMPRESSIVE LOADING

LM.FERREIRA (ESCUELA TÉCNICA SUPERIOR DE INGENIEROS, UNIVERSIDADE DE SEVILLA), E.GRACIANI, F.PARÍS

A mesoscale FE model of a NCF laminate with fibre crimped tows is used to study the progressive damage under compressive loading. The maximum strain criterion has been employed to determine the onset of the material damage under the loading.

25.3.4-R3 ALIGNED HEMP YARN REINFORCED BIOCOMPOSITES: POROSITY, WATER ABSORPTION, THERMAL AND MECHANICAL PROPERTIES

B.BAGHAEI (UNIVERSITY OF BORÅS), M.SKRIFVARS, M.SALEHI

Thermal and mechanical behaviour of aligned hemp composites using hemp/PLA wrap spun yarns in terms of hemp fibre orientation (aligned and random), off-axis angle and alkali treatment were investigated. The aligned alkali hemp/PLA yarn composite possessed the best mechanical properties.

25.3.4-R4 APPLICABILITY OF LATTICE REINFORCED CFRP PANELS IN AIRCRAFT FUSELAGE DESIGN

JP.FLÜH (TU BRAUNSCHWEIG), P.HORST

Nonlinear FEM calculations are used to analyze the applicability of lattice reinforced CFRP panels in comparison with a conventional reference panel. The comparison of the performance of those panels is made by applying global buckling-, maximum strain- and stress-criteria.

25.3.4-R5 ULTRASONIC POLAR SCAN IMAGING OF FATIGUED FIBER REINFORCED COMPOSITES

J.DEGRIECK (GHENT UNIVERSITY), I.DE BAERE, K.VAN DEN ABEELE, L.PYL, F.ZASTAVNIK et al.

Both tensile and shear-dominated fatigued carbon fabric reinforced PPS samples have been non-destructively characterized by the ultrasonic polar scan. Extreme fiber distortions and a directional reduction of the stiffness have been quantified.

25.3.4-R7 PRODUCTION AND PROPERTIES OF COMPOSITES BASED OF CARBON NANOTUBE FIBRES

B.MAS (IMDEA MATERIALS INSTITUTE), JJ.VILATELA

In this work, carbon nanotube fibres were produced and their electrical properties and structure were analized. These fibres were integrated in polymer matrices, and the properties of these composites were analized and related with the fibre structure.