Browsing by Author "Dell'Anno, Giuseppe"
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Item Open Access Automated manufacture of 3D reinforced aerospace composite structures(2012-03-05T00:00:00Z) Dell'Anno, Giuseppe; Partridge, Ivana K.; Cartié, Denis D. R.; Hamlyn, A.; Chehura, Edmon; James, Stephen W.; Tatam, Ralph P.Purpose- This study is part of the FP7 project ADVITAC and focuses on exploring an innovative combination of cutting edge technologies to be implemented within automated processes for composite parts manufacturing. The objective is the design of a production route for components with tailored fibre orientation and ply lay-up, with improved damage tolerance thanks to through-the-thickness reinforcement and integrated health monitoring systems based on optical fibres technology. Design/Methodology/Approach- The proposed technologies are described in detail and their compatibility and potential for integration are discussed. A set up for on-line monitoring of infusion and curing processes of carbon/epoxy laminates preformed by dry fibre placement technology is proposed, and a preliminary study of their mechanical performance is presented. The possibility of reinforcing through-the-thickness preforms manufactured with dry slit tapes automatically laid-up and consolidated by laser heating is investigated. Findings- Improved knowledge of interaction/compatibility between the discussed technologies and scope for application. Research limitations/implications- The paper reports the technical potential and practical feasibility of the proposed integrated production process. Limited quantitative evaluations on the materials performance are provided. The analysis of the technologies involved represents the early outcome of the ongoing ADVITAC project. Practical implications- This study contributes to the identification of a new generation of composite architecture which allows production cost and weight savings while retaining the level of quality suitable for demanding structural applications, with particular relevance to the aerospace field. Originality/value- This paper investigates for the first time the practical possibility of designing a single automated process involving dry fibre placement, tufting and optical fibre sensor monitoring for the production of complex composite components.Item Open Access Effect of tufting on the mechanical behaviour of carbon fabric/epoxy composites(Cranfield University, 2007-11) Dell'Anno, Giuseppe; Partridge, Ivana K.This work draws some early baselines on the in-plane/out-of-plane properties balance in a 5HS woven carbon fabric/epoxy composite reinforced by tufting and resin injected by resin transfer moulding technique. Details of the manufacturing processes involved in the preparation of such through-the-thickness reinforced composites are presented together with analysis of the mesostructure of tufted specimens. Preforms were reinforced locally with a commercial glass or carbon fibre thread. The tufts were inserted in square arrangement with a KSL tufting tool interfaced to a 6 axis computer controlled robot arm from Kawasaki. The presence of tufts improved significantly the delamination resistance, assessed by testing double cantilever beam coupons in mode I loading configuration. In-plane tension and compression after im¬pact (CAI) tests revealed that the reinforcement resulted in a considerable increase in the post-impact residual strength value, with an accompanying drop down in static tensile modulus and strength of less than 10%. In addition to the standard coupons for the determination of the quasi-static mechanical properties, some cured miniature specimens containing a limited number of tufts were also prepared. These were tested in both uniaxial pull-out and in a mode II configuration in order to measure the bridg¬ing actions of the tufts and to determine the micromechanical failure mechanisms. The obtained crack bridging laws were used for calibrating a simple analytical model of the mechanical behaviour of a single tuft within the composite. The tufting technology was applied to an innovative concept that aims to adopt the tufting threads as a carrier for resin modifiers. For this purpose a single-filament and a multi-filament thermoplastic prototype threads were used. These threads are not intended to modify the composite fibre architecture but are expected to dissolve into and react with the host matrix upon cure. The outcome of mode I delamination and CAI tests conducted on woven preforms reinforced with such `soluble' threads are presented and discussed.Item Open Access Effect of water immersion on the interlaminar and flexural performance of low cost liquid resin infused carbon fabric composites(Elsevier Science B.V., Amsterdam., 2012-04-30T00:00:00Z) Dell'Anno, Giuseppe; Lees, RebeccaThis study investigates some potential benefits of using non-epoxy matrices in carbon fibre composites, targeting specific marine and wind energy applications. Water uptake during and after immersion for up to 28 days in deionised water at 40°C, and the effects of such conditioning on the interlaminar shear and flexural performance of the composites with isophthalic polyester, vinyl ester and urethane acrylate matrices were compared to those of equivalent composites impregnated with three grades of epoxy resin. Results demonstrated that, although the epoxy systems perform equally or better than the alternative resins in the dry state, they are also more sensitive to property degradation due to water ingress. The relatively lower water absorption and subsequent limited reduction in performance of vinyl ester and urethane acrylate composites is sufficiently promising to justify further studyItem Open Access Exploring mechanical property balance in tufted carbon fabric/epoxy composites.(Elsevier Science B.V., Amsterdam., 2007-11-01T00:00:00Z) Dell'Anno, Giuseppe; Cartié, Denis D. R.; Partridge, Ivana K.; Rezai, AmirThe paper details the manufacturing processes involved in the preparation of through-the-thickness reinforced composites via the ‘dry preform–tufting–liquid resin injection’ route. Samples for mechanical testing were prepared by tufting a 5 harness satin weave carbon fabric in a 3 mm × 3 mm square pitch configuration with a commercial glass or carbon tufting thread, infusing the reinforced preforms with liquid epoxy resin and curing them under moderate pressure. The glass thread reinforcement increases the compression-after-impact strength of a 3.3 mm thick carbon fabric laminate by 25%. The accompanying drop- downs in static tensile modulus and strength of the same tufted laminate are below 10%. The presence of tufts is also shown to result in a significant increase in the delamination crack growth resistance of tufted double-cantilever beam specimens and has been quantified for the case of a 6 mm thick tufted carbon non-crimped fabric (NCF)/epoxy cItem Open Access Investigation of the fracture behaviour of epoxy-based water ballast(Cranfield University, 2015-07) Wu, Tongyu; Irving, Phil E.; Ayre, David; Dell'Anno, GiuseppeThe fracture of water ballast tank (WBT) coatings due to thermal stresses is widely recognised as an issue. Upon coating fracture, rapid corrosion of the tanker steel structure will occur, leading to expensive structure repairs or even tanker scrapping. In this project, the fracture behaviour of two experimental WBT coatings, referred to as A and B, in the forms of free film and substrated coatings was investigated. Static tensile tests and fatigue tests of the substrated coatings were performed. A finite element model of coating cracking was developed. Thermal stress and J-integral of surface cracking defects in substrated coatings were calculated using the model, in which the effects of defect size, coating thickness, and thermal strain on coating fracture were investigated. For the first time, fracture mechanics was used to explain WBT coating fracture behaviour. The J-integral of surface defects was used to predict the onset strain of coating cracking under mechanical strains in laboratory and under thermal strains in service. A theoretical comparison between the cracking drive forces in terms of J - integrals in WBT coatings under thermal strains and mechanical strains was performed.Item Open Access On-line monitoring of multi-component strain development in a tufting needle using optical fibre Bragg grating sensors(Institute of Physics, 2014-05-20T00:00:00Z) Chehura, Edmon; Dell'Anno, Giuseppe; Huet, Tristan; Staines, Stephen E.; James, Stephen W.; Partridge, Ivana K.; Tatam, Ralph P.Dynamic loadings induced on a tufting needle during the tufting of dry carbon fibre preform via a commercial robot-controlled tufting head were investigated in situ and in real-time using optical fibre Bragg grating (FBG) sensors bonded to the needle shaft. The sensors were configured such that the axial strain and bending moments experienced by the needle could be measured. A study of the influence of thread and thread type on the strain imparted to the needle revealed axial strain profiles which had equivalent trends but different magnitudes. The mean of the maximum axial compression strains measured during the tufting of a 4-ply quasi-isotropic carbon fibre dry preform were - 499 ± 79 με, - 463 ± 51 με and - 431 ± 59 με for a needle without thread, with metal wire and with Kevlar® thread, respectively. The needle similarly exhibited bending moments of different magnitude when the different needle feeding configurations were used.Item Open Access Resin transfer moulding: Novel fabrics and tow placement techniques in highly loaded carbon fibre composite aircraft spars(Sampe Society for the Advancement of Material, 2007-06-30T00:00:00Z) Mills, Andrew; Patel, Zahir; Dell'Anno, Giuseppe; Frost, MatthewA BAE Systems /UK EPSRC funded project Flaviir, is investigating the design and manufacture of low cost carbon fibre composite airframe structures. Novel binder coated unidirectional fibre tapes and tows were developed to enable the design of optimised primary structures. The RTM technique was applied to mould net shape sections of spar components. Various designs of wing attachment lugs were manufactured with a range of reinforcement materials, including non crimp fabric, novel binder coated tapes and conventional unidirectional prepreg. Alongside these, a novel technique termed optimised tow lay up (OTL) was used to reduce the weight. Binder coated carbon fibre tow is placed around the structure in the principal stress directions to increase both bearing strength and overall component stiffness. The novel materials, manufacturing technique and initial element test results are presented.