24.1.1-R8 COMPARISON OF ALGORITHMS FOR 2D ANISOTROPIC PERMEABILITY CALCULATION IN TERMS OF UNCERTAINTY PROPAGATION

E.FAUSTER (MONTANUNIVERSITÄT LEOBEN), H.GRÖSSING, S.SCHLEDJEWSKI

Two well-known mathematical algorithms for computing two-dimensional permeability values are compared by studying the influence of stochastic material and test parameters on the permeability values. The analyses are based on Monte-Carlo experiments.

24.1.1-R9 X-RAY CHARACTERIZATION OF GLASS FIBRE REINFORCED THERMOPLASTIC ORIENTATION AND FATIGUE DAMAGE EVOLUTION FOR AUTOMOTIVE TECHNICAL PART

H.NOURI (ECOLE DES MINES DE DOUAI), A.AYADI, F.ROGER, H.MAITOURNAM, S.GUESSASMA et al.

The aim of this work is to implement the glass fibre orientation in the thickness, obtained by X-ray tomography, in order to simulate the fatigue damage evolution of GFRP automotive parts.

24.1.1-R10 AFOSR.1/3

24.1.1-R11 INFLUENCE OF NOTCH TIP RADIUS AND FIBRE ORIENTATION ON THE FATIGUE STRENGTH OF A SHORT GLASS FIBRE REINFORCED POLYAMIDE 6

A.BERNASCONI (POLITECNICO DI MILANO), E.CONRADO, P.HINE

The combined effect of notch tip radius and fiber orientation on the fatigue strength of a short fiber reinforced polyamide was investigated using plates having two symmetric V-shaped notches, with various fillet radii, injected longitudinally and laterally.

24.1.1-R12 A TOP-DOWN ANALYSIS FOR DETERMINING EDGE STRESSES IN COMPOSITE LAMINATES

F.MUJIKA (UNIVERSITY OF THE BASQUE COUNTRY), I.ADARRAGA, MA.CANTERA, JM.ROMERA

A top-down analytic approach is proposed to analyze the stresses that result of the constrained deformations in a symmetric laminate. In-plane and out-of-plane stresses in each ply prevent the coupling deformations and ensure the compatibility of displacements.

24.1.1-R13 A NUMERICAL STUDY ON ADHESIVE THICKNESS EFFECT ON BONDED JOINTS USING A MODIFIED FINITE-THICKNESS COHESIVE ELEMENT

C.SARRADO (UNIVERSITAT DE GIRONA), FA.LEONE, A.TURON, CG.DÁVILA

A cohesive formulation is proposed for modeling the elastic response, softening and failure of finite-thickness adhesives. By decoupling the penalty stiffness and the adhesive modulus, proper dissipation of fracture energy is ensured with any combination of elastic and fracture properties.

24.1.1-R14 INFRARED THERMOGRAPHY TO EVALUATE IMPACT DAMAGING OF COMPOSITES

C.MEOLA (UNIVERSITY OF NAPLES FEDERICO II), S.BOCCARDI, ND.BOFFA, F.RICCI, GM.CARLOMAGNO

The impact damaging of either thermoset, or thermoplastic, fiber (carbon, or glass) reinforced composites is investigated with infrared thermography, which is used for both monitoring of the composite surface being impacted and for non destructive evaluation before and after impact.

24.1.2-R8 ON THE USE OF DIC-3D TO DETERMINE THE PERMEABILITY TENSOR AND COMPACTION LAWOF FABRIC BY VARTM

J.VILA (IMDEA MATERIALS INSTITUTE), C.GONZÁLEZ, J.LLORCA

This contribution investigates the VaRTM manufacturing process from the viewpoint of the compaction phenomena. The panel thickness evolution during the infiltration was measured using a three dimensional digital image correlation technique and modeled by Darcy’s equation and level set approach.

24.1.2-R9 FATIGUE DELAMINATION INITIATION IN L-BEND CFRP COUPONS

J.BLANCHFIELD (UNIVERSITY OF BRISTOL), G.ALLEGRI

Issues arising from the use of a test method for obtaining SN curves for the initiation of delamination due to pure interlaminar tension in a CFRP are presented. The results are then used in an analytical damage evolution model.

24.1.2-R11 RESEARCH INTO THE DIRECT ADHESION OF PA66 TO STEEL USING STRUCTURED METAL SURFACE

K.KOSE (INPRO INNOVATIONSGESELLSHAFT FÜR FORTGESCHRITTENE PRODUKTIONSSYSTEME IN DER FAHRZEUGINDUSTRIE MBH), I.CLAUSNER, F.EGGERS, B.FAISST

By structuring the metal surface a direct adhesion of PA66 to steel/ aluminum without the use of primers or adhesives can be achieved. Experiments show that this gives a stable bond even for high stresses due to different thermal expansions.

24.1.2-R12 ESTIMATION OF THE REINFORCEMENT FACTOR Xi FOR CALCULATING E2 WITH THE HALPIN-TSAI EQUATIONS USING THE FINITE ELEMENT METHOD

E.GINER (UNIVERSIDAD POLITECNICA VALENCIA), V.FRANCO, A.VERCHER

An estimation of the reinforcement factor xi of the Halpin-Tsai equations used to calculate the transverse stiffness E2 is provided. Using FE analyses, it is concluded that xi=1.5 is a better estimation than the original value of xi=2.

24.1.2-R13 FINITE ELEMENT MAPPING FOR A STRUCTURAL ANALYSIS OF COMPOSITES

N.MAYER, R.HINTERHÖLZL (INSTITUTE FOR CARBON COMPOSITES, TECHNISCHE UNIVERSITÄT MÜNCHEN, FACULTY OF MECHANICAL ENGINEERIN), J.PROWE

An improvement of a structural simulation is realized with data sets from process simulations. A main challenge is to provide a mesh-independent interface for FE data conversion. In this work, an approach for mapping based on FE data is presented.

24.1.2-R14 INFLUENCE OF THERMAL CYCLING ON THE LOW VELOCITY IMPACT RESPONSE OF CFRP LAMINATES

D.GHELLI (UNIVERSITY OF BOLOGNA), V.CANTARINI, E.TROIANI

Results of low velocity impact tests on unidirectional CFRP laminates, previously aged with up to 80 thermal cycles between -16 °C/+80 °C, are presented, in order to assess the effect of repeated temperature changes on the impact behavior of material.

24.1.3-R8 FAST AND EFFICIENT PERMEABILITY AND COMPACTION CHARACTERISATION OF DRY TEXTILES: CONSIDERATIONS FOR A PROPOSED TECHNIQUE

A.WALBRAN (INSTITUTE FOR CARBON COMPOSITES, TECHNICAL UNIVERSITY OF MUNICH), H.KÖRBER

Developing methods for efficient material characterisation. Large experimental studies carried out, covering a range of process and material parameters. Together with a survey of industrial end-user requirements to assess key requirements for efficient characterisation methods.

24.1.3-R9 EFFECT OF ALTERNATE CHANGE IN STRESS RATIO ON FATIGUE STRENGTH OF WOVEN FABRIC CFRP LAMINATE AND LIFE PREDICTION USING THE ANISOMORPHIC CFL DIAGRAM

M.KAWAI (UNIVERSITY OF TSUKUBA), K.YANG, S.OH

A simple engineering methodology that uses the Miner rule and the anisomorphic constant fatigue life diagram approach allows efficiently predicting the fatigue life of a woven CFRP laminate under alternating R-ratios loadings with an accuracy of a factor of two.

24.1.3-R11 CHARACTERIZATION OF DAMAGE MECHANISMS IN GLASS FIBRE REINFORCED POLYMERS USING X-RAY COMPUTED TOMOGRAPHY

D.SALABERGER (UNIVERSITY OF APPLIED SCIENCES UPPER AUSTRIA), M.ARIKAN, T.PAIER, J.KASTNER

3D characterization of heterophasic polymers by means of X-ray computed tomography High resolution XCT for materials science

24.1.3-R12 SOLVING STRESS EQUATIONS IN COMPOSITE CYLINDERS

L.RIPOLL, JL.PEREZ APARICIO (UNIVERSITAT POLITECNICA VALENCIA), P.MAIMÍ

We analyze stresses in cylindrical flywheels as function of axial distance from the edge to calculate approximated analytical formulation that can predict the distribution of the out-of-plane components. The exact three-dimensional governing equations are integrated, neglecting just a few terms.

24.1.3-R13 BRIDGED DEFECTS IN UNI-DIRECTIONALLY-REINFORCED COMPOSITES

P.SELVADURAI (MCGILL UNIVERSITY)

The paper examines the mechanics of a penny-shaped defect in a unidirectionally reinforced composite. The penny-shaped defect is in the matrix and the fibres exhibit continuity across the faces of the crack. The resulting Fredholm Integral equation is solved numerically.

24.1.3-R14 INDUSTRIAL WOVEN NON-CRIMP MULTILAYER FABRICS FOR BETTER IMPACT PROPERTIES

M.HAESKE (RWTH AACHEN), BM.WENDLAND, L.VAN DER SCHUEREN, YS.GLOY, T.GRIES

In this research project “Multi-NonCrimp”, it is shown that multilayer 3D interlock weaves with minimal warp and weft crimp can be produced on full width weaving looms. Woven fabrics are impregnated and mechanically characterized by 3-point flexural and bending test.

24.1.4-R8 MODELLING THE FLUID-POROUS INTERFACE IN LIQUID COMPOSITE MOULDING PROCESSES

X.ZHAO (UNIVERSITY OF NOTTINGHAM), AC.LONG, X.ZENG, F.GOMMER

24.1.4-R9 STUDY OF THE INTERLAMINAR QUASI-STATIC AND FATIGUE BEHAVIOUR OF A CARBON PPS USING THE SINGLE LAPSHEAR GEOMETRY

I.DE BAERE (GHENT UNIVERSITY), W.VAN PAEPEGEM, J.DEGRIECK

This manuscript presents a method of producing such benchmark lapshear specimens for a hot pressed carbon fabric reinforced thermoplastic. The mechanical behaviour of these specimens is then assessed using quasi-static and tension-tension fatigue experiments.

24.1.4-R11 THERMOMECHANICAL BEHAVIOUR OF SHORT GLASS FIBRE REINFORCED POLYAMIDE

A.AYADI, F.ROGER (MINES DOUAI), H.NOURI, H.MAITOURNAM, I.RAOULT

In Short-glass-reinforced-polyamide-66 composites, fiber distribution plays a major role on the mechanical properties. Even for simple geometry, the mechanical fields are heterogeneous. We propose to use infrared-thermography and simulation to monitor heterogeneous dissipation during tensile tests for various fiber distributions.

24.1.4-R12 FAILURE ANALYSIS OF A RUNOUT CONFIGURATION WITH BUTT-STRAP JOINT

A.ESTEFANI, A.BLÁZQUEZ (UNIVERSITY OF SEVILLE), J.REINOSO, F.PARÍS, J.CAÑAS

Runout regions are zones where stiffener is interrupted. This paper deals with the numerical analysis of a runout specimen. A butt-strap is used to soften the transmission load from the section with stiffener to the section without stiffener.

24.1.4-R13 MOLECULAR MODELING OF CRACKS AT INTERFACES IN NANOCERAMIC COMPOSITES

F.PAVIA (EPFL), WA.CURTIN

Toughening in nanoscale Ceramic Matrix Composites (CMCs) is investigated by using direct atomistic models capturing how an impinging matrix cracks behave as a function of the degree of interfacial bonding/sliding between carbon nanotubes (CNTs) and a diamond matrix.

24.1.4-R14 EXPERIMENTAL AND NUMERICAL STUDY OF OBLIQUE IMPACT ON HELICOPTER BLADES – INFLUENCE OF THE CURVATURE

F.PASCAL, P.NAVARRO (INSTITUT CLÉMENT ADER), S.MARGUET, JF.FERRERO, J.AUBRY et al.

This work focuses on the study of medium velocity oblique impacts on the lower surface of composite helicopter blades. The influence of the local curvature of the blade on the response to impacts is investigated.