25.4.1-R1 NEW APPROACH TO SURFACE PREPARATION FOR ADHESIVE BONDING OF AERONAUTICAL COMPOSITES: ATMOSPHERIC PRESSURE PLASMA. STUDIES ON THE PRE-TREATMENT LIFETIME AND DURABILITY OF THE BONDLINE

J.SÁNCHEZ (REY JUAN CARLOS UNIVERSITY), A.UREÑA, S.LAZCANO, T.BLANCO

The feasibility of Atmospheric Plasma as surface pre-treatment for aeronautical composites prior to structural adhesive bonding was studied. As a result, the combination of release compounds removal, chemical activation and new topographical features were correlated with excellent long-term adhesion properties.

25.4.1-R2 PREDICTING THE NOTCHED STRENGTH OF LARGE QUASI-ISOTROPIC COMPOSITE LAMINATES BASED ON SMALL SPECIMEN TESTS

X.XU (UNIVERSITY OF BRISTOL), MR.WISNOM, SR.HALLETT

Size effects are studied to understand the relation between the notched tensile strength of the large specimens and that of the small coupons. Two scaling laws for large quasi-isotropic composite laminates with sharp and blunt notches respectively are focused on.

25.4.1-R3 THERMOMECHANICAL AND DEGRADATION BEHAVIOR OF BIO-BASED MATRIX NANOCOMPOSITES

P.GEORGIOPOULOS, E.KONTOU-DROUGKA (NTUA), A.MERISTOUDI, S.PISPAS

The thermomechanical properties of Poly(lactic Acid) and its nanocomposites, based on silica are extensively studied. The degradation process at specific conditions, simulating the conditions into the human body has also been examined,by Size Exclusion Chromatography (SEC) and Thermogravimetric Analysis (TGA).

25.4.1-R5 BENDING CHARACTERISTICS OF 3D WOVEN CARBON COMPOSITES

P.TURNER (THE UNIVERSITY OF NOTTINGHAM), T.LIU, X.ZENG

Investigating the elastic behaviour and failure modes of 3D-orthogonal woven carbon composites via cantilever structural testing. Two differing binder densities are compared. No influence of binder density with long beam, whilst distinctive differences in energy absorption with short beam tests.

25.4.1-R6 ELECTRICAL RESISTANCE CHANGE OF INTERLAMINAR WOVEN-FABRIC CFRP IN MODE II FRACTURE

Y.NISHIO (TOKYO INSTITUTE OF TECHNOLOGY), A.TODOROKI, Y.MIZUTANI, Y.SUZUKI

Electrical resistance change under Mode II shear fracture was composed of three stages and explained using two mechanical models according to delamination crack propagation. Electrical resistance increase caused by fiber breakages at the crack tip remained as permanent change.

25.4.1-R7 COST EFFECTIVE ENCAPSULATION COMPOSITES FOR BUILDING INTEGRATED PHOTOVOLTAICS

MA.GONZÁLEZ (ECOLE POLYTECHNIQUE FEDERAL DE LAUSANNE), R.TEUSCHER, R.TWEEN, P.VELUT, Y.LETERRIER et al.

A multilayer polymer composite material system and process for encapsulation of thin film solar cells into profiled roofing elements were developed. The multilayer included texturized hybrid nanocomposites for enhanced light trapping and a glass fiber reinforced composite for structural integration.

25.4.2-R1 USE OF FULL-DEPTH POST-TENSIONED GFRP RODS FOR BOND PERFORMANCE UNDER MIXED MODE BENDING CONDITIONS

D.CHEN (UNIVERSITY OF CALGARY), R.EL-HACHA

Full-depth partially bonded post-tensioned GFRP rods for improved bond performance in full-scale hybrid structural members were studied. Substantially increased load resistance and maximum deflection were obtained through comparative MMB experimental testing. Non-prestressed post-tensioned GFRP rods are recommended for future use.

25.4.2-R2 SIZE EFFECT ON DAMAGE EVOLUTION IN OPEN-HOLE COMPOSITE LAMINATES

MM.MOURE, SK.GARCÍA-CASTILLO, S.SANCHEZ-SAEZ, E.BARBERO (UNIVERSITY CARLOS III OF MADRID), EJ.BARBERO

In this work, a DDM model is employed to study damage evolution in open-hole laminates subjected to in-plane tensile loads. The influence of the stacking sequence on the evolution of crack density and notched strength of the laminate are analyzed.

25.4.2-R3 IMPROVEMENT OF THE INTERPHASE STRENGTH AND THE MOISTURE SENSITIVITY OF FLAX FIBRE REINFORCED BIO-EPOXIES: EFFECT OF VARIOUS FIBRE TREATMENTS

D.PERREMANS (KU LEUVEN), Y.GUO, J.BAETS, AW.VAN VUURE, I.VERPOEST

In this paper the joined effect of water, alkalization and silane treatment on the durability of flax bio-epoxies at ambient and increased humidity. It is shown that the tensile stress-strain curve remains tri-linear irrespective of the humidity or fibre pre-treatment.

25.4.2-R5 AVALANCHE FAILURE OF YARNS IN A 3D WOVEN COMPOSITE: FINITE ELEMENT MULTI-SCALE MODELLING BASED ON TOMOGRAPHY INSPECTION

L.LAIARINANDRASANA (MINES PARISTECH), W.TRABELSI, A.THIONNET

Finite element modelling based on tomographic inspections was perfomed. The results showed that according to the kind of applied load, the numerical simulations of warp yarn breakage led to either avalanche or progressive failure.

25.4.2-R6 MONITORING HYGROTHERMAL DAMAGE IN GRAPHITE-EPOXY LAMINATE USING FIBER BRAGG GRATING

CS.SHIN (NATIONAL TAIWAN UNIVERSITY), PK.TSAI, SK.LIAW

Embedded FBGs can detect internal swelling under simulated hygrothermal treatment and during subsequent low-energy impact followed by cyclic loading, the easier spread of the damage in the weakened matrix was revealed by a pre-matured disappearance of the FBG reflection peak.

25.4.2-R7 MECHANICAL PROPERTIES OF CNT-GRAFTED CARBON FIBER COMPOSITES

G.LEE (SEOUL NATIONAL UNIVERSITY), JH.YOUK, J.LEE, WR.YU

We prepared hierarchical CNT-grafted CFs without their mechanical degradation by Ni-Fe bimetallic catalyst CVD. Various CNT-grafted CF composites were manufactured and their mechanical properties were evaluated, focusing on the effects of CNT-grafted CF on the mechanical properties of the composites.

25.4.3-R1 EVALUATION OF CRITICAL FRACTURE ENERGY OF ADHESIVELY BONDED JOINTS FOR CARBON COMPOSITES UNDER COMBINED-MODE HIGH-STRAIN RATE LOADINGS

T.FURUSAWA (HONDA R&D CO.,LTD.), T.SHIMAMIYA, E.YOKOI, K.SATO, H.HATTORI et al.

Fundamental technology research center, Honda R&D Co.,Ltd.

25.4.3-R2 MODELLING OF MECHANICAL BEHAVIOUR OF POLYMERIC COMPOSITES WITH NONLINEAR CONSTITUENTS

L.PUPURE (LULEÅ UNIVERSITY OF TEHCNOLOGY), J.VARNA, R.JOFFE

Applicability of Schapery models in form of stress/strain is explored by analysing experimental data from creep and relaxation tests. Relaxation curves are modelled by incremental simulation procedure. Comparison of viscoelastic parameters obtained from simulated and experimental relaxation curves is performed.

25.4.3-R3 THE EFFECT OF ALKALIZATION ON THE MECHANICAL AND WATER ABSORPTION PROPERTIES OF NON-WOVEN KENAF FIBER/UNSATURATED-POLYESTER COMPOSITES PRODUCED BY RESIN-TRANSFER MOLDING (RTM)

ZA.MOHD ISHAK (UNIVERSITI SAINS MALAYSIA), D.ARIAWAN, MS.SALIM, R.MAT TAIB, MZ.AHMAD THIRMIZIR et al.

This paper focuses on kenaf fibre/polyester composites manufactured by RTM. The influence of fiber treatment was investigated with dynamic contact angle,tensile, flexural, ILSS, fracture toughness, DMA and SEM measurements. Overall, alkalized composites gave superior mechanical properties compared with untreated composites.

25.4.3-R5 DETERMINATION OF MANUFACTURE INDUCED VARIABILITY AND PREDICTION OF THE RESULTING MECHANICAL PROPERTIES OF A COMPOSITE

F.GOMMER (UNIVERSITY OF NOTTINGHAM), R.BROOKS

The effect of yarn path variability on resulting mechanical properties in a fibre reinforced composite is analysed. An automated image analysis method was developed to obtain statistical reinforcement data during lay-up and models of critical zones were created.

25.4.3-R6 PIEZOELECTRIC MULTIFUNCTIONAL COMPOSITES DAMAGE DETECTION USING THEIR MODAL EFFECTIVE ELECTROMECHANICAL COUPLING

A.BENJEDDOU (SUPMECA, PARIS, FRANCE), M.HAMDI

The modal effective electromechanical coupling coefficient is investigated as a damage indicator in smart composites. Hence, 3D piezoelectric finite element analyses are first conducted for healthy state; then, this parameter’s change factor is assessed for fixed and varied damage characteristics.

25.4.3-R7 NANOPARTICLES-EFFECT ON THE MECHANICAL AND ELECTRICAL PROPERTIES OF PET-BASED HYBRID COMPOSITES

CN.VEIGA BARBOSA (IPC/I3N – INSTITUTE FOR POLYMERS AND COMPOSITES), P.PEREIRA, F.GONÇALVES, JC.VIANA

The effect of hosting different weight percentages of nanoclays or carbon nanofibers into the unreinforced and glass fiber reinforced poly(ethylene terephthalate) matrices has been evaluated in terms of the mechanical and electrical performance of the final composites.

25.4.4-R1 WORK OF ADHESION BETWEEN METALS AND POLYMERS ON A MACRO- AND MICROSCOPIC SCALE

M.FÜLLBRANDT (TECHNICAL UNIVERSITY BERLIN), D.KESAL, R.VON KLITZING

Polymer/metal hybrids are of interest e.g. in lightweight constructions used in the automotive industry. The joining of these dissimilar materials without using additional material is a central challenge. The adhesion is studied by atomic force microscopy and contact angle measurements.

25.4.4-R3 DAMPING PERFORMANCE OF FLAX FIBRE COMPOSITES

F.DUC (ECOLE POLYTECHNIQUE FÉDÉRALE DE LAUSANNE (EPFL)), PE.BOURBAN, JA.MANSON

Dynamic mechanical analysis and vibration beam testing have been used to assess the damping properties of unidirectional, laminated and woven flax fibre/epoxy composites. Friction mechanisms at fabric, yarn and fibre level were identified and quantified.

25.4.4-R5 THE OUT-OF-PLANE BEHAVIOUR OF SPREAD-TOW FABRICS

M.SZPIEG, M.WYSOCKI (SWEREA SICOMP), P.HELLSTRÖM, F.OHLSSON

In this paper the compressive behaviour of spread-tow textile reinforcement is studied. The striking result of our analysis is that the spread-tow type of reinforcement obey linear relation between force and deformation, which is in contrast to standard reinforcements.

25.4.4-R7 OPTIMAL MANUFACTURING PROCESS OF SELF-HEALING MICROCAPSULES FOR DAMAGE REPAIR TECHNIQUES IN POLYMERIC COMPOSITES

SH.YOON (KUMOH NATIONAL INSTITUTE OF TECHNOLOGY), MS.KIM, JO.OH, SY.JANG, MR.KESSLER

Optimal manufacturing process for self healing microcapsules was investigated. Morphology was observed by optical microscope and FE-SEM. Size distribution and weight changes were measured by PSA and TGA. Suggested methodology enables microcapsules with acceptable thermal stability and improved storage capability.