23.1.1-R8 MOULDABLE SMC/BMC AUTOMOTIVE COMPOSITES FROM SUSTAINABLE RESOURCES

L.SAVAGE (UNIVERSITY OF EXETER)

Mouldable, Short fibre thermoset composites- Sheet Moulding Compounds (SMC) represents the leading volume-fabrication route for structural composites for the automotive market. Lightweight bio-derived versions were developed in this study, where improvement in impact performance was a critical objective.

23.1.1-R9 INVESTIGATION OF THE VERY HIGH CYCLE FATIGUE BEHAVIOUR OF GFRP CROSS-PLY BENDING SPECIMENS

TJ.ADAM (TECHNISCHE UNIVERSITÄT BRAUNSCHWEIG), P.HORST

A test rig for high frequency testing of GFRP flat specimens has been developed to provide experiments reaching the very high cycle fatigue range. First fatigue data including stiffness degradation and evaluation of crack density and delaminated area are presented.

23.1.1-R10 KEY FACTORS FOR CHARACTERIZING DELAMINATION FATIGUE PROPERTIES IN TOUGHENED CFRP

M.HOJO (KYOTO UNIVERSITY), N.SATO, M.NISHIKAWA

The roles of fiber architectures, matrix resin and its structure on the delamination fatigue properties are summarized for toughened laminates. The key factors to correctly evaluate the fatigue delamination are discussed from the viewpoints of mechanism consideration.

23.1.1-R11 CFRP AND ALUMINUM STACKS DRILLED IN ONE DRILLING STEP IN 25 MICRONS OF TOLERANCE

C.RAMIREZ (AIRBUS OPERATIONS S.L.), F.TORRES, M.HORN

This paper show the development work for defining a one shot drilling process between Airbus and Klenk at hybrid stacks and with holes diameter requirement of 25 µm. This project is based on Advanced Drilling Units and new cutter geometries.

23.1.1-R12 TENSILE BEHAVIOR OF A CFRP WIRE ROPE WITH INDEPENDENT CORE: ANALYTICAL AND NUMERICAL ANALYSES

F.LUZ, L.SILVA, S.AMICO, C.CIMINI (UFMG)

In this paper CFRP wire ropes were studied using two mathematical models: (i) analytical model based on the theory of wire rope for isotropic materials and (ii) finite element model. Comparison between models yielded prediction deviations within 5%.

23.1.1-R13 MODELLING OF THE RESIDUAL STRESS STATE IN A NEW TYPE OF RESIDUAL STRESS SPECIMEN

J.JAKOBSEN (AALBORG UNIVERSITET), JH.ANDREASEN

This paper relates to residual stress assessment in composite materials. A specimen comprising of a steel plate with circular hole stacked in between several layers of CSM glass/epoxy has been analysed. Model prediction correlated well with in situ strain measurements.

23.1.1-R14 STRUCTURAL RESPONSE AND DAMAGE RESISTANCE OF SANDWICH COMPOSITES SUBJECTED TO LOW VELOCITY IMPACT

D.FENG, A.CERIONI, F.AYMERICH (UNIVERSITY OF CAGLIARI)

Impact tests were conducted on sandwich panels with different carbon/epoxy skins and PVC foam core densities to characterize type and extent of damage. Experimental data were used to assess the predictive capabilities of a FE model developed by the authors.

23.1.2-R8 STIFFNESS-MODIFIABLE COMPOSITE FOR PEDESTRIAN PROTECTION

A.BACHINGER (SWEREA SICOMP), E.MARKLUND, J.RÖSSLER, P.HELLSTRÖM, LE.ASP

The development of a novel functional material allowing stiffness-reduction upon external stimulation is described. Implementation of such technology in the design of a car front has high potential to result in increased protection of vulnerable road users.

23.1.2-R9 FATIGUE ANALYSIS OF WIND TURBINE COMPOSITES USING MULTI-CONTINUUM THEORY AND THE KINETIC THEORY OF FRACTURE

P.GREAVES (NAREC), P.MCKEEVER, R.DOMINY, T.KOZIARA

This paper presents a quantitative analysis of the optimum method of using multi-continuum theory and the kinetic theory of fracture for multi-scale modelling of fatigue failure in composites. Results are presented for a range of R-values.

23.1.2-R10 EFFECT OF INCLINED INSERTION ON THE DELAMINATION RESISTANCE OF Z-PINNED COMPOSITES

B.M´MEMBE (UNIVERSITY OF BRISTOL), M.YASAEE, SR.HALLETT, I.PARTRIDGE

The bridging behaviour of single, inclined Z-pin specimens is studied under Mode I, Mode II and Mixed-Mode I/II conditions. The results show that increasing the insertion angle doubles the delamination resistance under Mode II and Mixed-Mode I/II loading.

23.1.2-R11 DRILLING OF THICK COMPOSITE STRUCTURES WITH PILOT HOLE USING A TWIST DRILL

P.RAHME (NOTRE DAME UNIVERSITY), Y.LANDON, R.PIQUET, F.LACHAUD, P.LAGARRIGUE

This paper presents an analytical and a numerical model that calculates the critical thrust force at delamination when drilling composite materials with pilot hole using a twist drill. These models are validated experimentally by realizing a series of punching tests.

23.1.2-R12 STRAIN ENERGY-BASED FORMULATION FOR STRUCTURAL ANALYSIS

L.BRAMBILLA (FACC , ST. MARTIN IM INNKREIS (AUSTRIA)), J.PLEWA

Abstract The increased use of composite materials in Aerospace in recent years is due to the weight reduction advantages. The drawback is that solid laminates and sandwich panels during manufacturing can be affected by a series of defects (skin depression, porosity, delamination, de-bonding… ), which then reduce the static and fatigue performances of the component. The Material Review Board (MRB) is responsible for repairing the component to restore its structure integrity in order to compl

23.1.2-R13 A SHELL ELEMENT FORMULATION FOR THE SIMULATION OF PROPAGATING DELAMINATION AND THROUGH-THICKNESS CRACKS

J.BROUZOULIS, M.FAGERSTRÖM (CHALMERS UNIVERSITY OF TECHNOLOGY), E.SVENNING

An enhanced shell element formulation for mesh independent FE-simulation of simultaneous through-thickness and multiple delamination crack propagation in orthotropic laminates is proposed. So far, the proposed modelling framework has been validated against pure deformation modes, as will be shown.

23.1.2-R14 IMPACT LOADING OF FRPS – FROM LOW TO HIGH SPEEDS

VV.SILBERSCHMIDT (LOUGHBOROUGH UNIVERSITY), V.PHADNIS, A.ROY

An extensive study of response of fibre-reinforced polymer composite laminates to various types of dynamic loading was carried out to understand complex damage mechanisms under impact loads within a broad range of velocities – from low to high.

23.1.3-R8 DESIGN AND DIMENSIONING STANDARDS FOR MULTI-MATERIAL COMPONENTS FOR THE AUTOMOTIVE INDUSTRY CONSIDERING THEIR FAILURE PROBABILITY

S.KLEEMANN (TU BRAUNSCHWEIG), T.VIETOR

Dependencies between the design strategy of composites, manufacturing process, material testing, maintenance and quality control are immense. The approach to manage these dependencies is a design catalog with design and dimensioning standards considering the design strategy for composites.

23.1.3-R9 DISCRETE DAMAGE SIMULATION AND MEASUREMENT IN COMPOSITE LAMINATES UNDER FATIGUE LOADING

E.IARVE (UNIVERSITY OF DAYTON RESEARCH INSTITUTE), K.HOOS, D.MOLLENHAUER

Fatigue properties of CFRP were studied intensively in the past and satisfactory described for most isolated damage modes. X-FEM methods are extended for simulation of fatigue loading to address evolution and interaction of various modes of damage.

23.1.3-R10 INVESTIGATION OF THE DELAMINATION CHARACTERISTICS OF COMPOSITE SPECIMENS WITH THROUGH THICKNESS REINFORCEMENT USING AN INERTIA CONSTRAINED SOFT BODY BEAM BEND TEST SPECIMEN

G.KALWAK (ROLLS-ROYCE), S.READ, M.JEVONS, N.PETRINIC

This paper presents the results from a test programme using a novel test specimen to investigate the delamination of carbon fibre composite specimens under impact loading. Specimen damage and z-pin failure modes are investigated using c-scanning, high-speed photography and fractography.

23.1.3-R11 INFLUENCE OF LASER IRRADIATION ON THE FAILURE BEHAVIOR OF UNIDIRECTIONAL FIBRE REINFORCED POLYMERS

A.FÜRST (TECHNISCHE UNIVERSITÄT DRESDEN), M.ROSE, A.KLOTZBACH, J.HAUPTMANN, T.HEBER et al.

The laser processing expands the area of possible kinds of processing strategies of FRP. The introduced test method is able to allegorize to the failure mode of inter fiber fracture as a function of laser cutting parameters.

23.1.3-R12 ANALYTICAL STUDY OF COMPOSITE PANEL FOR MANUFACTURING BOATS BY THEORY OF HETEROGENEOUS SECTION

AM.WAHRHAFTIG, PJ.HENRIQUE NETO (UNIVERSIDADE FEDERAL DA BAHIA), HJ.RIBEIRO, AN.NASCIMENTO

This job aims to analyze, based on the classical theories of Solid Mechanics for calculation of normal stresses, the flexion of web-core sandwich panel designed by Ribeiro, Wahrhaftig and Nascimento (2013) for marine applications.

23.1.3-R13 CHARACTERIZATION OF FIBER-REINFORCED STIFFENER PROFILES FOR AIRCRAFT FUSELAGE PRELIMINARY STRUCTURAL DESIGN

J.KRIEGLSTEINER (TECHNISCHE UNIVERSITÄT BRAUNSCHWEIG), P.HORST, C.SCHMIDT

The presented software module determines beam characteristics of stiffener designs for simplified representations in large FE-models. In contrast to available modules in common FE-software it allows for useful features for composite designs: inhomogeneous profiles, curved geometries, and core material.

23.1.3-R14 IMPACT CHARACTERIZATION OF POLYMER COMPOSITES BASED ON PEEK AND CARBON FIBRES

A.CALZOLARI (ITW TEST & MEASUREMENT ITALY), M.TOMMASONE, M.ZANETTI, M.REGIS, F.D'ACIERNO

The impact properties of four different CFR-PEEK composites were obtained by means of the instrumented impact technique. Results obtained, including the influence of reinforcement and crystallinity, allowed to identify the material with the best impact performances.

23.1.4-R8 CONCEPT DEVELOPMENT AND IMPLEMENTATION OF NEW HYBRID COMPOUNDS

N.NUBBO (FRAUNHOFER INSTITUTE FOR STRUCTURAL DURABILITY AND SYSTEM RELIABILITY LBF), A.FELDE, M.HEINRICH, J.DECKER, A.BÜTER et al.

A focal point in this paper is in the combination of materials with different coefficients of thermal expansion at high temperatures.The interaction of different material properties can improve the performance of components and reduce the weight of a vehicle.

23.1.4-R9 AN EFFICIENT ALGORITHM TO PREDICT THE EXPECTED END-OF-LIFE IN COMPOSITES UNDER FATIGUE CONDITIONS

M.CHIACHIO (UNIVERSITY OF GRANADA/NASA AMES RESEARCH CENTER), J.CHIACHIO, A.SAXENA, G.RUS, K.GOEBEL

This work presents a novel efficient algorithm for estimating the end of life by combining the particle filter-based prognostics with the technique of Subset simulation, resulting in a especially suited algorithm for the prognostics of laminate degradation under fatigue loads.

23.1.4-R10 HIGH-FIDELITY FE MODELLING OF Z-PINS IN QUASI-ISOTROPIC LAMINATES

B.ZHANG (UNIVERSITY OF BRISTOL), G.ALLEGRI, SR.HALLETT

This paper presents a three-dimensional FE modelling approach to simulate the mechanical response of individual Z-pins at the micro-scale and the associated bridging mechanism. This modelling strategy accounts for the characteristic features associated with Z-pinning.

23.1.4-R11 IMPROVING PERFORMANCE OF MACHINED GLARE LAMINATES FOR AEROSPACE APPLICATIONS

K.GIASIN (THE UNIVERSITY OF SHEFFIELD), A.HODZIC, S.AYVAR-SOBERANIS

23.1.4-R12 DEVELOPMENT OF AUTOMATED HIGH-FIDELITY FINITE ELEMENT MODELS FOR LARGE WIND TURBINE BLADES

M.PEETERS (GHENT UNIVERSITY), W.VAN PAEPEGEM

To improve the high fidelity finite element modeling of wind turbine blades an automated approach is used. It allows the generation of detailed shell and continuum models and can incorporate adhesive bonds to obtain a model that aligns with reality.

23.1.4-R13 NUMERICAL MODELING OF STRAIN LOCALIZATION IN FIBER REINFORCED COMPOSITES

T.NADABE (THE UNIVERSITY OF TOKYO), N.TAKEDA

This study investigates relationship between deformation phenomena of composite materials in strain localization and mathematical governing equations expressing the deformation. It is indicated that onset of arbitrariness in solution of governing equations is closely related with initiation of compressive failure.

23.1.4-R14 PREDICTION OF THE LOW-ENERGY IMPACT RESPONSE OF A SELF-REINFORCED POLYMER BASED ON A RHEOLOCIAL MODEL

JI.MÚGICA (MONDRAGON UNIBERTSITATEA), L.ARETXABALETA, I.ULACIA, M.MATEOS, J.AURREKOETXEA

A model to predict the contact force history during low-energy impacts on a self-reinforced polypropylene (SRPP) is proposed. It considers indentation, bending and membrane effects, as well as the non-linearity of the material. The model reproduces accurately the experimental data.