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1
Ah-Teck, Tommy C. T. "Formability of long glass-fibre reinforced polypropylene sheet." Thesis, Loughborough University, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329863.
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Sheard, P. A. "Transverse and environmental cracking of glass fibre reinforced plastic." Thesis, University of Surrey, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.374663.
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Attou, Abdelkader. "Cracking and stress corrosion cracking in glass fibre materials using acoustic emission." Thesis, Robert Gordon University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.277702.
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Williams, Gareth. "Development of self-healing carbon fibre reinforced plastic utilising an embedded hollow glass fibre delivery system." Thesis, University of Bristol, 2008. http://hdl.handle.net/1983/f6eeac30-dbc3-44f2-9911-8f5b6a877ba3.
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There is a drive for modem engineering structures to exploit the excellent specific properties of advanced fibre reinforced composite materials, particularly in aerospace, where manufacturers are under intense pressure to reduce costs and engineer lighter more efficient aircraft. However it is widely recognised that the susceptibility of these materials to transverse impact damage is restricting the extent to which these benefits can be exploited.
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Mohammadi, Yaghoub. "Compression creep measurements in pultruded angle sections made of fibre glass reinforced plastic." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=69738.
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A study aimed at investigating the performance of pultruded fibre glass reinforced plastic (FGRP) materials subjected to both the time-independent and the time-dependent response of angle stubs and coupons was conducted. Angle stubs and coupons were made of isophtalic polyester resin reinforced with an E-glass fibre glass mat of 35%-45% of the weight. The stub dimensions were of 50.8 mm $ times$ 50.8 mm $ times$ 6.35 mm and their length was 305 mm. The compression coupons were cut in a prismatic shape according to ASTM Standard D695-89 with 12.70 mm $ times$ 6.35 mm cross-section and a length of 31.75 mm.In the time-independent short-term study, the FGRP angle stubs and coupons were subjected to axial compression loading with two different testing configurations.
In the time-dependent long-term study, three angle stubs were first subjected to a 350 hour preliminary creep test, followed by 150 hours of creep recovery, with three lengths and configurations of strain gauges. Finally, a last series of tests was carried out on three angle stubs instrumented with 12 5-mm long gauges. Coupon creep tests were carried out in parallel with the stub tests. The total duration of the tests was 2500 hours in creep and 250 hours in creep recovery. Results indicate a scatter in the order of 15% in creep strain measurements after 2500 hours, for both stub and coupon tests. Predictions using Findley's power law with creep parameters determined from the stub tests and coupon tests are in excellent agreement, both with one another and with actual creep strain measurements on the stubs. The Boltzman superposition principle was used to compare the experimental creep recovery results with predictions from Findley's model, and excellent agreement was also observed. (Abstract shortened by UMI.)
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Saribiyik, Mehmet. "Analysis of a bonded connector for pultruded G.R.P. structural elements." Thesis, University of Newcastle Upon Tyne, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327192.
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Javed, Muhammad Afzal. "Stability analysis of P.F.R.P. box-sections." Thesis, University of Newcastle upon Tyne, 2003. http://hdl.handle.net/10443/3623.
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lass fibre reinforced plastic (GRP) structural profiles, in standard shapes and sizes are now being commercially manufactured by the process of pultrusion. GRP profiles are light weight, posses higher specific strengths and are more durable than the conventional metal or concrete counterparts. GRP pultruded profiles have open or closed cross-sections comprising thin composite walls of low elastic moduli. Stability failure has been identified as the main cause of failure for these profiles when subjected to compressive stresses, as it may occurs at stresses much lower than the ultimate strengths. Therefore, the load carrying capacities of composite compression members mainly depends upon stability criteria. The conventional stability analyses for the prediction of buckling loads are not considered adequate as the GRP material is orthotropic and its behaviour is different from steel (non-yielding). The existing guidance for the design of composite members under compression ignores the presence of geometrical imperfections inherited in the pultruded profiles, whilst, experimental evidence suggests considerable loss of stiffness due to the imperfections particularly in the intermediate column heights. The design guidance provided by the manufacturers gives empirical equations based on data obtained from experiments on specified profiles. A universal design curve based on the experimental results of concentrically loaded GRP columns has been developed and presented. However, conducting a vast experimental study is not always feasible. The need to develop a procedure, predicting failure load numerically for the development of a design curve for GRP columns has been recognised. Two GRP box-sections (closed square cross-sections) have been investigated for failure/buckling loads using experimental and numerical methods. In the experimental phase, specimen columns of various heights have been concentrically loaded in compression to measure the failure loads. Experimental results have been compared with the theoretical predictions made using classical methods and the equations given by the design manuals. Based on the experimental and analytical failure loads, an experimental design curve has been derived. In the numerical study, 3-dimensional full scale finite element models representing experimental configuration of the composite columns, have been analysed using both linear and nonlinear solutions. Imperfections of known amplitudes have been included parametrically to establish the sensitivity of the failure loads towards imperfections. Imperfect model have been calibrated for the estimation of imperfection amplitude present in the profiles using experimental data. Using the numerical and analytical data, a design curve has been derived establishing interaction coefficients for each profile. The numerical design curve is compared with the experimental design curve for the validation of the numerical procedure adopted in this study. Effects of perforations (circular holes) on the buckling stiffness of GRP box-section columns have also been investigated. Holes are drilled in the walls of profiles and tested experimentally to measure the loss in the buckling loads. Finite element models of columns with holes have been developed and analysed for buckling loads. Comparisons of experimental and numerical results are plotted. For use in the numerical representation of the composite columns, mechanical properties of the orthotropic GRP material of the both sections have been established analytically and experimentally. In-plane shear properties have been measured by physically testing standard sized coupons, extracted along the length of profiles. However, short coupons were available in the transverse directions due to dimensional constraints. Short coupons, similar in geometry to the standard coupon, but smaller in size, have been validated for performance using finite element analyses and comparing the outcomes with the models of standard coupons. Both standard and short coupons have been used for the experimental measurement of the in-plane shear properties. Compression properties have also been measured experimentally. Ultimate failure/buckling loads of the composite columns depend upon their heights, material properties, and the cross-sectional dimensions. These factors have been combined into one characteristic parameter 'λ', the slenderness ratio. As the later two factors are constant for a particular box-section profile, the ultimate loads depend upon column heights. Four types of failure modes; global, local, modal interaction and material failure have been observed. The loss in the buckling stiffness is minimal for smaller circular holes, provided the interval between holes is not less than 20 times the diameter of the holes. For bigger holes and an inter hole spacing of 10time the diameter, a loss of 30% have been measured. Finite element representation of pultruded columns adequately predicted the numerical failure loads and failure modes for most of the column heights.
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Berg, Jolyon. "The role of fibre coatings on interphase formation in glass fibre epoxy resin composites." Thesis, University of Sheffield, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245546.
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Short, Graeme John. "The effect of curvature on the impact performance of glass fibre reinforced plastic laminates." Thesis, University of Bristol, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.364963.
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Wells, Garry Michael. "The transverse mechanical behaviour of glass fibre reinforced plastics." Thesis, University of Bath, 1987. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380692.
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Kretsis, George. "Mechanical characterisation of hybrid glass/carbon fibre-reinforced plastics." Thesis, Imperial College London, 1987. http://hdl.handle.net/10044/1/46982.
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Nikolic, Marko. "Protection Structures of Glass Fiber Reinforced Plastic – Static Analysis." Thesis, KTH, Hållfasthetslära (Inst.), 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-103731.
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The oil- and gas industry has increasingly begun to switch from oil platforms and instead started to install the modules, process stations, etc. directly on the seabed. Some parts are more sensitive to external loads than others, and it is crucial to protect them to avoid damage on the structures and even gas/oil leakage. Protection covers made of glass fiber reinforced plastic (GRP) is becoming more frequently used in the offshore industry due to its low cost and good mechanical properties. Common load cases that the GRP cover could be exposed to have been identified and an investigation has been carried out to see what influence different factors like lay-up sequence and the number of plies has on the GRP cover. A fast and effective working method for future projects regarding GRP covers has been developed with the usage of Ansys and Excel. Analysis showed that for the installation and trawl net friction load cases the number of failed layers are very much dependent on the lay-up sequence of the GRP cover. Installation should be done vertically in order to prevent ply failure. For the trawl impact and Trawl Over-Pull load cases the numbers of failed plies are almost independent of the lay-up sequence. The conclusion is that lay-up sequences of [0/90]s and [-45/45]s are the most appropriate ones for this type of GRP cover and for the considered load cases. A total of 48 plies were recommended to ensure a completely intact protection structure for installation and trawl net friction, and only get small local failure at the trawl impact and over-pull load cases.
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Funke, Henrik, Sandra Gelbrich, Lars Ulke-Winter, Lothar Kroll, and Carolin Petzoldt. "An application of asymmetrical glass fibre-reinforced plastics for the manufacture of curved fibre reinforced concrete." Universitätsbibliothek Chemnitz, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-178054.
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There was developed a novel technological and constructive approach for the low-cost production of curved freeform formworks, which allow the production of single and double-curved fibre reinforced concrete. The scheduled approach was based on a flexible, asymmetrical multi-layered formwork system, which consists of glass-fibre reinforced plastic (GFRP). By using of the unusual anisotropic structural behavior, these GFRP formwork elements permitted a specific adjustment of defined curvature. The system design of the developed GFRP formwork was examined exhaustively. There were designed, numerically computed and produced prototypical curved freeform surfaces with different curvature radii.
The fibre reinforced concrete had a compressive strength of 101.4 MPa and a 3-point bending tensile strength of 17.41 MPa. Beyond that, it was ensured that the TRC had a high durability, which has been shown by the capillary suction of de-icing solution and freeze thaw test with a total amount of scaled material of 874 g/m² and a relative dynamic E-Modulus of 100% after 28 freeze-thaw cycles.
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Zhang, Xiangping. "Characterization of filament wound GRP pipes under lateral quasi-static and low velocity impact loads." Thesis, University of Aberdeen, 1998. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU551705.
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Glass-fibre reinforced plastic pipes are widely used to convey fluids for various purposes. They offer a number of distinct advantages over conventional metals, such as high specific strengths, high specific moduli, superior corrosion resistance and low coefficient of thermal expansion. However, their behaviour under lateral quasi-static and impact loading are still not well known. The research programme described in this thesis was designed to characterise the performance of 55° winding angle GRP pipes, subjected to lateral quasi-static and impact loading. Two approaches: experimental tests and finite element analysis, were used to investigate the behaviour of the GRP pipes. The experimental investigation was started with diametral compression of short GRP pipes to examine the structural behaviour and failure mechanisms. Subsequently, lateral indentation tests were conducted on rigid-foundation supported or simply supported specimens using two different indenter geometries: line-ended and flat-ended. Furthermore, low-velocity impact tests were performed under similar conditions as those for indentation tests in order to characterise the response of the GRP pipes and to identify the correlation between the two forms of loading. The pipes exhibited multi-mode failure mechanisms, resin cracks, delaminations and fibre breakage. It is found that delamination, which resulted in significant loss in stiffness and strength, was the most significant mode of failure for the GRP pipes. A good correlation in behaviour was identified between quasi-static indentation and its energy equivalent low-velocity impact when the global bending stiffness of the GRP specimens were high. Specimens with span S 10.5D i, where Di is the internal diameter of the pipe, are considered to have high bending stiffness, while simply supported specimens with S10.5D i have low bending stiffness. Irrespective of the support conditions and loading type, specimens with high bending stiffness followed a failure mechanism sequence: local resin failure, delamination and the fibre breakage. However, the large global bending experienced by low bending stiffness specimens resulted in a change of failure mechanism, only local damage and surface tensile cracks were observed.
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McClelland, Alan Nigel Robert. "The injection moulding of long glass fibre reinforced thermoplastic materials." Thesis, University of Liverpool, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235520.
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Ulas, Esref M. "The comparative performance and behaviour of concrete elements containing glass-fibre reinforced plastic reinforcing bars." Thesis, Sheffield Hallam University, 2001. http://shura.shu.ac.uk/20467/.
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Corrosion of steel reinforcement is a major concern in concrete construction, particularly in aggressive environments. Therefore corrosion resistant materials such as fibre composites are becoming increasingly feasible as an alternative concrete reinforcement. There are relatively few reported design guidelines for fibre composites in concrete. Hence, there is an urgent need for research and development to extend existing guidelines and standards such as those produced by the UK Institution of Structural Engineers and the ACI Committee (US), to encourage the wider use and acceptance of fibre composites as an alternative to steel in reinforced concrete elements. This investigation compares the behaviour and properties of a range of reinforced concrete beams under two point loading comprising different concrete grades and types using both steel and Glass Fibre Reinforced Plastic (GFRP) as primary and secondary reinforcement. A variety of conventional and 'novel' rebar configurations were used to assess their effect upon material efficiency and load capacity. Compressive and tensile strength and elastic moduli of all component properties were measured together with load, deflection, rebar and concrete strains on the reinforced concrete beams. Health and safety concepts through a risk assessment process were introduced for the testing at an early stage of the investigation. Principal measures of beam performance include the ultimate load capacity, stiffness and failure modes together with a 'performance quotient'; a mathematical expression derived as an efficiency comparator for beams of different types and composition. Photographic and video records were also used to monitor behaviour throughout. Experimental measurements generally showed good agreement with the corresponding theoretical, quasi-theoretical and design based values although the latter tended to overestimate the structural performance of the beams. In general, load capacity increased with increase in main rebar area but was affected to a lesser extent by concrete strength. The beams reinforced with steel had a greater load capacity than those reinforced with GFRP. However, GFRP reinforced beams generally displayed a greater capacity to absorb energy than steel but exhibited reduced stiffness at any given load although this was enhanced by the inclusion of glass fibres in the mix. Cracks in the GFRP reinforced beams were usually larger and deeper compared with those in the equivalent steel reinforced beams. Failure of the more lightly reinforced steel beams, including one GFRP beam, were predominantly in 'flexure'. The more heavily reinforced steel and the remainder of the GFRP reinforced beams exhibited mostly 'shear-bond' type failure. The 'novel' rebar geometry proved to be a simple, efficient and viable alternative to conventional rebar configurations in terms of load capacity and preferred mode of failure. It is suggested that further developments and applications could focus on small reinforced concrete elements such as lintels in aggressive environments and further refinement of the 'performance quotient' concept.
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Tao, Shicheng. "Bond of glass-fiber-reinforced-plastic reinforcing bars to concrete." Diss., The University of Arizona, 1994. http://hdl.handle.net/10150/186823.
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The objective of this research project was to study the bond behavior of Glass-Fiber-Reinforced-Plastic (GFRP) reinforcing bars (rebars) to concrete. A total of 102 specimens were experimentally investigated and theoretically analyzed at The University of Arizona. The static tensile load was applied to the rebars in a gradual increment of load level until splitting of concrete, rebar pull out failure, or rebar fracture occurred. The slip between the rebars and concrete was measured at the loaded and free ends at each load level. Variables included in the specimens were concrete compressive strength, embedment length, clear concrete cover, rebar diameter, concrete cast depth, radius of bend, tail length, and lead embedment length. On the basis of the experimental results, the study showed that concrete compressive strength, embedment length, clear concrete cover, concrete cast depth, and radius of bend had significant effects on bond of GFRP rebars to concrete. New criteria for acceptable bond performance of GFRP rebars to concrete were established. Furthermore, the practical design guidelines for calculating the development lengths of straight and hooked GFRP rebars to concrete were determined. In addition, confinement factors were also derived to reflect the influence of concrete cover and casting position.
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White, Roger John. "Environmental creep mechanisms in glass/polyester composites." Thesis, University of Bath, 1985. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.353403.
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A previous study, looking at the creep-rupture behaviour of mixed reinforcement GRP when immersed in water, had discovered that low loads, behaviour became temperature sensitive. Since the recorded time to failure of a sample was reduced at elevated temperatures, from that predicted by a linear extrapolation of the short term creep-rupture results, this deviation caused problems in the accurate prediction of long-term design stresses. In order to improve the accuracy of long term design predictions, it was decided to study the mechanisms of creep in GRP that initiates time dependent failure. From this, it was hoped that accurate design criteria suitable for predicting GRP response over a 30 year design life from short term creep tests, could be developed. This thesis reports the results obtained from such a study. A series of creep tests were performed on mixed reinforcement GRP samples at several stress levels, both in air, and in room temperature distilled water, using a microcomputer based data collection system. In conjunction with this work, damage development in samples, due to combinations of water uptake and creep loading, was followed, using both scanning electron, and optical, microscopy. Moisture uptake measurements were undertaken under a series of load/temperature regimes, and fibre/matrix debonding followed using photographic techniques. In this way, water absorption, both in terms of uptake rate, and location within a sample, could be characterised. Tensile tests were also performed to determine the standard mechanical properties of the mixed reinforcement GRP used. It was found that a critical damage state was created at loads in excess of 50% of ultimate, but not below. This took the form of between 2 and 8 neighbouring filament breaks in the longitudinal woven rovings at weave crossover points, producing microcracks in the reinforcement. The creation of this multifilament fracture damage during primary creep, was considered to be necessary for time dependent failure to occur in air. Secondary greep strain was found to increase in discrete steps, both in air and water. This was attributed to the formation of transverse grasks in the longitudinal woven rovings, propogating from the above critical damage. In water, diffusion was found to be non-Fickian. Moisture uptake increased with increases in applied load and temperature. Water was seen to accumulate at weave cross-over points when immersed under load. This led to stress-enhanced fibre corrosion in these regions, weakening the reinforcement, and reducing the failure time from that expected at the same load level in air. The localised nature of moisture degradation was thought to result in the formation of critical fibre damage at loads below 50% of ultimate, when immersed in water. Two design criteria based on the observed creep mechanisms, have been developed for GRP that predict response when loaded in either air, or water. Both predict the existence of creep-rupture limits at low loads.
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Zahir, Aishath Zehereen. "Degradation of e-glass fibre in selected organic acids." Curtin University of Technology, Department of Applied Chemistry, 2008. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=128425.
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E-glass has been widely used as a reinforcing material for years, especially as a plastic reinforcer in the production of GRP (Glass Reinforced Plastic). Failure of GRP materials under stress came in to the picture quite recently. Since then studies have been conducted in an attempt to understand the causes and the underlying behaviour.Except for the last section of the research (analysis using a kinetic approach) where glass fibre was cut out to weigh approximately 1.0g, standard sized specimens were soaked in the required acid solutions of desired concentrations for varying temperatures and time frames. Wherever tensile strength retention was measured, LLOYD instrument was employed. Leaching of the cations were analysed using Inductively Coupled Plasma – Optical Emission Spectroscopy (ICP-OES and also know and ICP-AES).
The scope of this project can be divided in to four sections; first section involved investigating the effects of malonic acid. The study of malonic acid was narrowed to investigating the trend in strength retention. A rapid strength loss was observed initially followed by a much steady decline in the strength. However the continuation of the loss of strength was unmistakable throughout the time period of exposure. Furthermore, temperature can be observed as a facilitating factor in this degradation reaction.
Secondly the corrosive effect of glyoxylic acid on E-glass fibre was studied. This was explored at two different temperatures for two specific time frames using various concentrations of the acid of interest. The influence of this acid on the glass fibre was found out in terms of strength retention and loss of cations from the glass matrix. The mildness of this acid was accentuated by the fact that 70% or more of the strength was retained at all the conditions employed. A minima in strength retention was observed at 2M acid concentration similar to the trends observed in the past (Betz and Jones 2003 and Jones and Chandler 1986). Leaching of cations reflected this trend. The large strength retention could be related to the fewer amounts of Ca and K leached from the glass matrix (Kumosa and Qui, 1997). Similar to malonic acid, an unusually large amount of B was leached out that could be due to the favourable orientation of the anion with the trivalent ions during the complex formation. Yet again temperature was found to enhance the degradation process.
Next the extent of passivation (if any) showed by malonic acid was investigated using E-glass fibre pre-treated in 5M malonic acid and post treated in known corrosive acids hydrochloric acid and oxalic acid. Passivation of malonic acid was put to test through examination of strength retention of the fibres under these conditions. This segment was carried out as an extension of a finding (a behaviour synonymous to passivation) shown by malonic that surfaced the previous year by the present researcher. Increasing the pre-treatment time showed a great improvement in the retained strength for all the post-treatment acid mediums. Furthermore, while Jones and Betz (2004) featured 20-40% strength retention within a short time frame in 3M HCl, the immense amount of strength retention (60-70%) preceding pre-treatment should definitely be noted. Similarly strength retention of about 80% was observed when post-treated with the severely corrosive oxalic acid. Hence its is clear that passivation can be induced through prolonged pre-treatment in 5M malonic acid that could inhibit the attack of corrosive acid at least for a period of time.
The last fragment of the study focussed on understanding and working out the mechanism behind the reactions between the E-glass fibre and acid medium in terms of kinetics. The acids utilized were 1.5M malonic acid and 3M glyoxylic acid and the assessments were made through the analysis of the weight changes brought about by the acid medium at various temperatures and time frames. In addition leaching patterns of cations were evaluated as this could contribute in achieving the objective. Maximum weight loss reached 4% in glyoxylic acid while that for malonic acid exceeded 20%. The general trend was that the glass fibres lost weight in both acids for a period of time followed by an evident weight gain. Furthermore the weight loss results fit the first order rate law. While the leaching of cations reflects the weight loss for the shorter time frames, steady loss of ions was visible even for the longer time frames where the weight has increased. The weight gain could be explained in terms of binding of anions to certain cations on the glass surface, accounting for the hindrance in the loss of cations at the longer time frames as well. About 50% of weight loss was associated to Ca while 20% was to Al, leaving 6% to B where as the rest of the ions had shown almost insignificant contribution to the weight loss.
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Hill, Alistair R. "The mechanical properties of glass fibre reinforced and rubber toughened polypropylene." Thesis, University of Surrey, 1991. http://epubs.surrey.ac.uk/843764/.
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The mechanical properties and fracture mechanics of a series of short glass fibre reinforced and rubber toughened polypropylene composite grades has been studied. The microstructural characteristics of composite grades were examined and, through appropriate models, related to the observed mechanical properties. The moulded material was modelled as being composed of fibre reinforced plies of varying average fibre orientation. The rubber was distributed uniformly throughout the specimens. The main effect of the rubber was to reduce the stiffness of the matrix and hence also the efficiency of the load transfer at the fibre/matrix interface while at the same time improving the fracture toughness and critical strain energy release rate of the matrix. Automated image analysis has been used to characterise the rubber particles' size, shape and distribution, and glass fibres' length and orientation distributions. The fibre/matrix interface has been studied using a novel single fibre fragmentation technique. Iterative computer simulations have been developed to accurately predict the stress-strain response of the various grades. The fracture mechanics properties of this series of materials are highly strain rate sensitive. At low strain rates the addition of glass fibres reduces the toughness of the material because the fibres act as discontinuities within the matrix, aiding initiation and propagation of a crack. At higher strain rates the fibres toughen the material by increasing the energy dissipation associated with fibre pull-out. These effects result in changes in the fracture surface morphology. Fibres pulled-out at low strain rates had clean surfaces. At higher strain rates the surfaces of pulled-out fibres were coated in an adherent sheath of matrix material. These effects are considered to be a consequence of the viscoelastic nature of the matrix. At low strain rates the matrix deforms plastically. At impact speeds the matrix responds in a predomoninantly brittle manner.
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Aasrum, Pål Einar. "A numerical and experimental investigation of glass fibre reinforced epoxy pipes /." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0016/MQ55014.pdf.
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Pollard, Andrew. "The mechanical performance of reinforced plastics in a deep sea environment." Thesis, University of Salford, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239987.
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Hu, Fang Zong. "Fatigue of glass reinforced plastic pipes and joints for offshore applications." Thesis, University of Newcastle Upon Tyne, 1997. http://hdl.handle.net/10443/678.
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In this thesis the static and fatigue characteristics of glass filament wound plastic pipes and joints are examined by experiments and numerical analysis. A hydraulic fatigue test rig, capable of exerting static or cyclic pressures of up to 70 MPa, was designed and built to enable pressure tests to be carried out on glass reinforced epoxy and glass reinforced vinyl ester composite pipes incorporating various joints. Static weepage and burst tests were performed on tubular specimens with and without rubber liners to determine their weepage and burst strengths under internal hydraulic pressure and to investigate the influence of the joints. Fatigue weepage tests were performed to determine the fatigue life and failure modes of glass fibre/epoxy and glass fibre/vinyl ester pipes and joints. For each material system, three types of specimen were tested. These were plain pipes, pipes with coupler-bonded joints (or laminate joints in the case of vinyl ester resin based pipes) and pipes with spigot/socket bonded joints. All specimens were commercial products with nominal diameters of two inches (50 mm). A family of curves showing pressure versus life was obtained. It was observed that weepage mostly occurred close to the pipe joints when pipes were subjected to internal pressure. Optical microscopy was used to investigate the damage initiation and propagation mechanisms in the specimens after testing. Finally, two-dimensional and three-dimensional finite element analyses were carried out to calculate the stress and strain distributions, to predict the strength, to interpret the experimental results and to examine the failure modes of the specimens. Ply-by-ply stress analysis and the Tsai-Wu failure criterion were employed for the strength prediction.
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Lee, Hon. "Fatigue behavior of concrete beams prestressed with glass fiber reinforced plastic (GFRP) tendon /." View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202007%20LEE.
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Ball, Ryan. "Experimental analysis of composite reinforced concrete beams." Ohio : Ohio University, 1998. http://www.ohiolink.edu/etd/view.cgi?ohiou1177002341.
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Ho, Chia-Hua. "Mechanical behavior of three-point bending for unidirectional glass fiber reinforced plastic (GFRP) box beams /." Available to subscribers only, 2005. http://proquest.umi.com/pqdweb?did=1083541381&sid=15&Fmt=2&clientId=1509&RQT=309&VName=PQD.
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Bonfield, Stephanie. "Influence of the fibre/matrix interface on the physical and mechanical behaviour of E-glass reinforced thermoplastics." Thesis, University of Surrey, 1993. http://epubs.surrey.ac.uk/843994/.
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The performance of a composite is not only dependent on the properties of the constituent elements, the fibre, the size and the matrix, but also on the interface between them. Good interfacial bonding is essential for the effective transfer of stress from the matrix to the fibre. Two methods of improving the interfacial adhesion in E-glass reinforced thermoplastics have been studied, namely by coating the fibre with a size specific to the matrix, or by using an in-situ reactive processing technique to activate the matrix itself. The size modification and the matrix modification systems were evaluated in E-glass reinforced thermoplastics with matrices of polyamide 6.6 and polypropylene, respectively. The elements which constitute the composite, namely the fibre, the size and the matrix, were characterized both individually and when combined in the composite. Both polymers presented spherulitic structures, however, the nature of these crystallites was shown to be dependent on both the processing conditions and the chemical modification, for the polypropylene. The physical properties of the unreinforced matrices were examined by tensile testing and by viscoelastic analysis, and were shown to be structure-related. The characterization of the size coating on the fibres proved difficult due to the small dimensions of the fibre, the very thin size layer and the insulating nature of the specimens which resulted in charging with electron microscopy techniques. However, by employing a wide range of experimental methods the polymer of the size and the fibre/size interface were successfully charcterized. The behaviour of the size was found to be dependent on the type of matrix reactive polymer added to the silane coupling agent. The composite materials, of both systems, were characterized structurally, by employing image analysis to examine the fibre length and orientation distributions, and transmission optical microscopy to observe the matrix. The fibre length and orientation distributions were found to be dependent on the processing conditions employed, but independent of the interfacial modification, of both systems. The mechanical properties of the composites were measured by tensile testing and viscoelastic analysis. Three methods were developed to evaluate the strength of the fibre/matrix bonding in the injection moulded composites: Viscoelastic analysis, with a torsion pendulum was shown to be sufficiently sensitive to detect variations resulting from the type of size applied to the fibres, or the addition of small quantities of modifying agents to the matrix polymer. The composite was characterized, in its bulk form, by comparing the damping properties of the material. An adhesion efficiency model was developed to rank the composites with respect to their interfacial bond strength. This method was found to be an effective tool for comparing the different adhesion enhancement systems. The third method employed was the microdrop test which provided a direct measurement of the interfacial shear stress in each system.
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Turmel, Denis Jean-Pierre. "Effect of phase separation in epoxy/PEI matrix on the mixed-mode I/II delamination behaviour of unidirectional glass fibre reinforced composites." Thesis, Cranfield University, 1995. http://dspace.lib.cranfield.ac.uk/handle/1826/11335.
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The study reported in this thesis investigates the relationships between the morphology of PEI/epoxy blends reinforced with glass fibres and their fracture properties. Hot stage optical microscopy is used to study the phenomenon of phase separation in the thermosetting blends in the presence of glass, carbon and aramid fibres. Phase separation is shown to be unaffected by the presence of aramid and carbon fibres, but is affected by the presence of glass fibres, to a degree which mainly depends on the PEI concentration. Other parameters like cure temperature, the nature of the glass fibre surface and fibre volume fraction are also examined. The most striking feature is the initiation and development of an epoxy-rich layer around the fibres for blends modified with 15 wt % PEI. This concentration corresponds to a co-continuous network of PEI-rich particles embedded in an epoxy-rich matrix. The effects of morphologies formed during phase separation on the fracture properties of glass fibre-reinforced composites are studied using the mixed-mode bending test rig developed by NASA. Extensive scanning electron microscopy (SEM) observations provide qualitative support to the delamination results. They show that different micro-mechanisms of deformation can occur, depending on the matrix microstructure and the fibre/matrix interfacial strength. SEM observations show that cusps are not only present under mode II loading, but also under mixed-mode I/II loading. They reveal that the spatial density and angle of cusps depend on the applied loading mode, the interfacial strength and the nature of the matrix itself. These observations are the base of a model which describes the delamination behaviour of composites from pure mode Ito pure mode II loading.
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Sanchez, Urbina Israel. "Optimizing flow of plastic PBT with 45% glass and mineral fiber reinforcement in an injection over mold process using Taguchi, CPk and mold flow simulation software approaches." To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2009. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.
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Gurer, Goksu. "Design And Characterization Of Electromagnetic Wave Absorbing Structural Compsites." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612359/index.pdf.
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Electromagnetic interference (EMI) is one of the most common problems encountered in microwave applications. Interaction of electromagnetic (EM) waves from different sources may result in device malfunction due to misinterpretation of the transferred data or information loss. On the other hand, development of materials with reduced radar detectability is desired in defense applications. Considering the limitations in weight and thickness, development of lightweight structural materials with enhanced electromagnetic absorption potential is needed. In this study, development and characterization of glass fiber-reinforced polymer (GFRP) composite materials to be used in EM wave absorbing or EMI shielding applications was aimed. Incorporation of electromagnetic wave absorption characteristic has been achieved by the application of conductive thin film on fiber glass woven fabric reinforcement layers. Characterization of EM wave absorption potential was conducted using &ldquofree-space method&rdquo
in 18 &ndash
27 GHz frequency range. Single and multilayered combinations of surface-modified fiber glass woven fabrics were characterized in terms of their EM wave interaction properties and design principles for efficient broadband EM wave absorbing multilayered GFRP composite material have been presented. A computer aided computation method has also developed in order to predict EM wave transmission, reflection, and hence absorption characteristics of multilayered structures from single layer properties. Estimated results were verified compared to free-space measurement results. In the current study, up to 85% electromagnetic wave absorption has been obtained within 18-27 GHz frequency range (K band). Enhancement of EM wave absorption potential of multilayer structure has also been demonstrated by computer aided computation.
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Ziehl, Paul Henry. "Development of a damage based design criterion for fiber reinforced vessels /." Full text (PDF) from UMI/Dissertation Abstracts International, 2000. http://wwwlib.umi.com/cr/utexas/fullcit?p3004409.
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Damiani, Thomas Miles. "A model to predict the long-term strength of e-glass fiber composites subjected to environmental exposure." Morgantown, W. Va. : [West Virginia University Libraries], 2000. http://etd.wvu.edu/templates/showETD.cfm?recnum=1517.
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Thesis (M.S.)--West Virginia University, 2000.Title from document title page. Document formatted into pages; contains xiii, 86 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 81-84).
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Kalluri, Rajesh K. "Bending behavior of concrete T-beams reinforced with glass fiber reinforced polymer (GFRP) bars." Morgantown, W. Va. : [West Virginia University Libraries], 1999. http://etd.wvu.edu/templates/showETD.cfm?recnum=1147.
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Thesis (M.S.)--West Virginia University, 1999.Title from document title page. Document formatted into pages; contains xi, 100 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 96-99).
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Lopez, Delphine. "Comportement d’un thermoplastique renforcé de fibres de verre soumis à des chargements thermo-mécaniques." Thesis, Lorient, 2018. http://www.theses.fr/2018LORIS488/document.
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Les composites à matrice polymère sont de plus en plus utilisés dans le secteur automobile. Afin de remplir les conditions exigeantes du cahier des charges vis-à-vis des conditions de mise en service, les pièces en composite doivent maintenir leur forme géométrique sous des conditions thermo-mécaniques parfois extrêmes. Par exemple, un assemblage de hayon composite est soumis à des contraintes mécaniques élevées associées à des variations de température importantes lors des essais de validation du cahier des charges. Les enjeux de la thèse sont axés sur l’aide à la conception dans le domaine quasi-statique de pièces industrielles injectées en thermoplastique renforcé de fibres discontinues. L’amélioration des outils numériques doit permettre un dimensionnement virtuel optimal de ces pièces en anticipant les variations rencontrées en service et les distorsions résiduelles résultantes de chargements thermo-mécaniques. Cette démarche s’appuie sur la connaissance du comportement thermo-mécanique du matériau de l’étude, celui du renfort de hayon, un polypropylène renforcé à 40% en masse de fibres de verre discontinues, et sur la modélisation du comportement de ce type de matériauDiscontinuous fibers reinforced thermoplastic materials have been widely used for several years in the automotive industry. These parts must resist demanding service life conditions and must meet thermo- mechanical specifications. Indeed, structural automotive spare parts have to endure high temperatures, like a few tens of degrees Celsius, for a long duration, at least a few hours. As an example, a structural part of tailgate is subject to high mechanical loading, associated to strong temperature variations, during the validation test, regarding specifications. The purpose of this work is to improve the design of complex industrial parts, like the tailgate in quasi-static domain, by relying on numerical simulation. One of the challenges related to the use of such material, is to have a reliable virtual design of industrial parts by predicting the geometrical variations during service life conditions, and residual strain. Therefore, it is necessary to characterize and to model the thermo-mechanical behavior of the tailgate material, a polypropylene matrix reinforced with discontinuous glass fibers, with a given mass fraction of 40%
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Qureshi, Muhammad Asif Mahmood. "Glass-fiber reinforced polymer-clay nanocomposites in structural applications." Morgantown, W. Va. : [West Virginia University Libraries], 2009. http://hdl.handle.net/10450/10557.
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Thesis (M.S.)--West Virginia University, 2009.Title from document title page. Document formatted into pages; contains xi, 71 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 69-71).
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Magrini, Michael A. "Fiber reinforced thermoplastics for ballistic impact." Birmingham, Ala. : University of Alabama at Birmingham, 2010. https://www.mhsl.uab.edu/dt/2010m/magrini.pdf.
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Cao, Qian. "Development of pseudo-ductile permanent formwork with glass fiber reinforced plastics reinforcements /." View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202007%20CAO.
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Choi, Jeong-Hoon. "Design and short-term performance of continuously reinforced concrete pavements using glass fiber reinforced polymer rebars." Morgantown, W. Va. : [West Virginia University Libraries], 2008. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=6043.
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Thesis (Ph. D.)--West Virginia University, 2008.Title from document title page. Document formatted into pages; contains xvii, 314 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 264-270).
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Singh, Peter. "Molding behaviour and microstructure of injection molded short glass fiber reinforced polypropylene composites." Thesis, McGill University, 1989. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=74240.
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Injection molded Short Glass Fiber Reinforced Thermoplastics (SFRTP) are widely used in industry because of advantages in material properties, availability, economics and ease of processing. The thermo-mechanical history experienced by the material during processing produces significantly anisotropic microstructural and consequently mechanical properties, varying not only spatially, but directionally.This work attempts to examine quantitatively various aspects of microstructure and the effect of processing conditions in SFRTP. The matrix phase properties, such as crystallinity, morphology and molecular orientation distribution, as well as the fiber phase microstructure such as concentration, length and orientation distributions have been analyzed quantitatively, and explained. Experimental techniques, including optical and electron microscopy, differential scanning calorimetry, Fourier transform infrared spectroscopy, thermo-gravimetric analysis, etc. have been used. The results indicate complex changes in microstructure from skin to core in the injection molded samples. Both matrix and fiber phase microstructures are affected by the basic thermal and flow processes that occur during the injection molding process. A first order model has been developed to predict fiber orientation distributions, which agree well with the experimental results.
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Garland, Chrystal A. "Effect of manufacturing process conditions on the durability of pultruded vinyl ester/glass composites." Morgantown, W. Va. : [West Virginia University Libraries], 2000. http://etd.wvu.edu/templates/showETD.cfm?recnum=1774.
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Thesis (M.S.)--West Virginia University, 2000.Title from document title page. Document formatted into pages; contains x, 125 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 83-86).
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Shyha, Islam Saad Elsayed Mohamed. "Drilling of carbon fibre reinforced plastic composites." Thesis, University of Birmingham, 2010. http://etheses.bham.ac.uk//id/eprint/1353/.
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Following an extensive literature survey focusing on the machinability of carbon fibre reinforced plastics (CFRP), three main phases of experimental work were undertaken to evaluate the drilling of CFRP and associated stack materials. Phase 1 and 2 involved small diameter holes (1.5 mm) in thin CFRP laminates (3 mm thick) while Phase 3 addressed the feasibility of one-shot drilling (6.35 mm diameter holes) in multilayer workpiece stacks comprising titanium, CFRP and aluminium. Machinability was assessed in terms of tool life/wear, force/torque, hole size and geometrical accuracy, workpiece surface integrity and chip morphology.
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Eisenheld, Leopold. "Measuring the Adhesive Bond Quality of Vinyl Ester-Glass Composites on Novolak HMR Treated Wood." Fogler Library, University of Maine, 2003. http://www.library.umaine.edu/theses/pdf/EisenheldL2003.pdf.
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Abdulmajid, Amin Ali Ahmed. "Strengthening of reinforced concrete beams using carbon fibre reinforced plastic." Thesis, Heriot-Watt University, 2007. http://hdl.handle.net/10399/1998.
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El-Chiti, Fadi. "Experimental Variability of E-Glass Reinforced Vinyl Ester Composites Fabricated by VARTM/Scrimp." Fogler Library, University of Maine, 2005. http://www.library.umaine.edu/theses/pdf/El-ChitiF2005.pdf.
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Esong, Ivo Epie. "Compression buckling of glass fibre reinforced cylinders." Thesis, Imperial College London, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.322666.
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Thibodeau, Elisabeth Gabrielle. "Static and Fatigue Fracture Characterization of Primary and Secondary Bonded Woven E-Glass Composites." Fogler Library, University of Maine, 2007. http://www.library.umaine.edu/theses/pdf/ThibodeauEG2007.pdf.
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Shekar, Vimala. "Effect of fiber architecture on properties of pultruded composites." Morgantown, W. Va. : [West Virginia University Libraries], 2007. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=5225.
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Thesis (M.S.)--West Virginia University, 2007.Title from document title page. Document formatted into pages; contains ix, 118 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 117-118).
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Allard, Austin. "Energy-Saving Non-Metallic Connectors for Precast Sandwich Wall Systems in Cold Regions." Thesis, North Dakota State University, 2014. https://hdl.handle.net/10365/26840.
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Conserving energy in large structural buildings has become very important in today's economy. A number of buildings today are constructed with sandwich wall panels. Steel connections are most commonly used in these panels. The problem with steel is that it has a tendency to reduce the thermal resistance of the insulation. This project considers glass fiber reinforcing polymers (GFRP) and carbon fiber reinforcing polymers (CFRP) as an alternate material to steel. An experimental sandwich wall panel was constructed and subjected to freezing temperatures. The results of the experimental program were compared to a theoretical model using the ANSYS computer program. The model was verified using current analytical methods that determine the heat flux of a sandwich wall panel. The methods investigated include the parallel path, zone, parallel flow, and isothermal planes methods. The results suggest that the GFRP connectors perform slightly better than the steel and CFRP connectors.ND EPSCoR
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Giraldi, Andre Luis Ferrari de Moura. "Compositos hibridos de poli (tereftalato de etileno) (PET) / fibra de vidro (FV) / modificador de impacto (E-MA-GMA)." [s.n.], 2008. http://repositorio.unicamp.br/jspui/handle/REPOSIP/267212.
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Orientadores: Lucia Helena Innocentini Mei, Jose Alexandrino de SousaTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
Made available in DSpace on 2018-08-12T07:01:46Z (GMT). No. of bitstreams: 1 Giraldi_AndreLuisFerrarideMoura_D.pdf: 6788806 bytes, checksum: f1a0282da8520c3138e10549183d79b6 (MD5) Previous issue date: 2008
Resumo: Uma aplicação importante do poli (tereftalato de etileno) - PET - pós-consumo a ser considerada, e ainda pouco explorada, diz respeito ao seu reaproveitamento em outros setores diferentes, tais como o de compósitos híbridos de fibra de vidro (FV) com matriz polimérica e modificador de impacto, para aplicações diversas na área de engenharia. Deste modo, se fez necessário um estudo sistemático de compósitos de PET, reforçado com fibra de vidro e modificador de impacto para sua utilização numa aplicação de engenharia. E necessário que este apresente uma boa relação entre propriedades de rigidez e resistência ao impacto, e para isto dois sistemas de reforço foram propostos com dois tipos de fibra de vidro com diferentes tratamentos superficiais (FV 952 e 983). Ensaios de reometria de torque indicaram a reatividade entre os componentes PET e modificador de impacto. Os ensaios mecânicos demonstraram que o modulo elástico e a resistência a tração dos compósitos diminuem conforme se aumenta a concentração de E-MA-GMA em substituição ao PET na matriz. Entretanto, o modulo e a resistência ao impacto aumentaram da ordem de 300 % e 900% respectivamente para as concentrações de 30% de fibra de vidro (FV 952) e 20% de E-MA-GMA. O modulo de elasticidade e independente do tipo de tratamento superficial da fibra de vidro. A resistência a tração e a resistência ao impacto Izod dependem da natureza do tratamento de silano usado.
Abstract: An important application of poly(ethylene terephtalate) - PET - to be considered, and still not well explored, is its re-use in other different sectors, such as the obtaintion of PET composites reinforced with fibre glass (FG) and elastomer, for several applications in the engineering area. In this way, it is necessary a systematic study of several PET composites hybrids reinforced with fibre glass and impact elastomer to obtain a good balance between engineering properties such strength, rigidity ans impact resistance, two systems of reinforced were investigated using two types treatment of surface different (FG 952 and 983). Torque rheometry investigations during composite mixing indicated the reactivity between PET and elastomer. Mechanical tensile test on PET / fibre glass / elastomer composites hybrids indicated that the elastic modulus and tensile strength reduce monotonically as higher volume fractions of E-MA-GMA substitute PET in the composite matrix. Composites hybrids with 30 wt% of fibre glass (FG 952) and 20 wt% of elastomer indicates mechanical gains of the order of 300% in modulus e 900 % Izod impact. Tensile modulus is relatively independent of type of silane treatment applied to the glass fibers. Yield strength and Izod impact strength depend on the nature of silane treatment used.
Doutorado
Ciencia e Tecnologia de Materiais
Doutor em Engenharia Química
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Subagio, Bambang Sugeng. "Contribution à la modélisation de l'endommagement de fatigue en flexion dans les matériaux composites unidirectionnels." Ecully, Ecole centrale de Lyon, 1987. http://www.theses.fr/1987ECDLA008.
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Essais d'identification d'une loi locale d'endommagement de fatigue basée sur la théorie de Kachanov-Rabotnov à partir d'essais mécaniques. Intégration de cette loi dans un calcul de structure. Introduction de la notion de dispersion par l'application d'une loi de Weibull. Identification de la dispersion locale à partir de la dispersion globale par la méthode de simulation de Monte-Carlo.