Дисертації з теми "Reinforcement fabrics"

Hybrid systems with two or more fiber materials were used to combine the benefits of each fiber into a single composite product. Strength and toughness optimization of hybrid thin sheet composites has been studied extensively using combination of different fiber types with low and high modulus of elasticity. Hybrid reinforcement is more significant when the reinforcing structure is in fabric geometry. Fabric structure provides full control on the exact location of each yarn and its orientation in the composite during production, thus maximizes the reinforcing efficiency. A high-strength, high-modulus fiber primarily tends to increase the composite strength with nominal improvements in toughness. A low-modulus fiber expected to mainly improve toughness and ductility. Combination of two or more types of fiber can produce a composite that is both strong and tough as compared to a mono fiber composite. The purpose of the current work was to study hybrid warp knitted fabrics as reinforcement for cementbased composite, having AR (Alkali Resistance) glass and Polypropylene (PP) as the reinforcing yarns. The examined ratios between the two different yarns were 0:100, 25:75, 50:50, 75:25, 100:0 (glass: PP, by percentage). It was found that in the hybrid system, the fracture mechanism is a superposition of the mono systems, and the tensile behavior is a combination between the two materials.

The aim of this project was to design, produce and assess multilayer fabrics with crosslinks or stitches between the individual layers so that the interlaminar shear properties of the composite panels reinforced with these fabrics would be improved. In fact, 12 fabric variants based on a 2-layer a-end satin fabric (with a more number 3Up) were produced on a 4x1 SAURER 100W Shuttleloom, which was modified in order to weave these fabrics. 3-D cellulorr fabrics with novel triangular cores were also woven on this shuttleloom. All of the 2-layer a-end satin fabric variants (including one non-stitched (weave No.9); five weft stitched (weave No.s 32,33,19,34,25); three warp stitched (weave No.s 36,37,29) ; and four weft and warp stitched fabrics (weaves Nos. 35,38,39,40) were assessed for their mechanical performance, particularly in Tensile and Interlaminar shear deformations. A geometrical model, "MAMCA" ("Major and Minor Circular Arc") model, was proposed in order to describe the yarn paths (warp and weft) in all the above fabric variants. using this model ("MAMCA"), the average breaking load of warp and the maximum initial angle between the warp yarn and the fabric axis (ximax.warp)' the theoretical breaking load along the warp direction was estimated for all 13 fabric variants tested. The theoretical values of the breaking load of the above fabric variants in the warp direction, were compared to the Experimental values obtained from Tensile strip strength Tests. There was a reasonable degree of agreement between these two sets of breaking load values. Thus, this method could be used to predict the breaking load of such fabrics in the appropriate loading direction.

Aerospace structural components made from polymer matrix composites (PMCs) offer numerous advantages. Their high stiffness and high strength combined with low densities enable lower fuel consumption coupled with higher payloads. As a result, PMCs provide an important economic advantage over typical metallic airframes. Textile reinforcements for PMCs are made by assembling reinforcement fibres, typically carbon. Then, the textile reinforcements are typically cut into smaller pieces, stacked, draped and assembled into a dry assembly called a preform, the shape of which generally approaches that of the PMC part to be made. This manufacturing process is labour intensive and expensive. Novel thick, net-shape, drapable, high vf textile reinforcements used toward manufacturing aerospace PMCs are being developed at the University of Ottawa. The technology enables the manufacturing of flat, drapable multilayered near net-shape preforms. The bending and in-plane shear behaviours of such novel thick reinforcement textiles was investigated to understand and define the behaviour of such thick fabric reinforcements when formed into required shapes. A bending apparatus was developed for investigating the bending behaviour of these novel thick reinforcement fabrics and an articulated frame shear rig was used for investigating the in-plane shear behaviour. A non-destructive inspection method using infrared imaging was used for investigating and identifying flaws and defects in these thick, dry textile reinforcements, aiming at increasing the quality and reproducibility of the final PMC parts made from these reinforcements.

Concrete has many advantages as a low cost and sustainable material. However, more than 5% of the planet’s total carbon emissions are associated with the production of cement, which, in fact, is predominantly due to the large volume of concrete used worldwide. It is known that traditionally designed concrete structures typically use more material than structurally required and, therefore, an important question is whether material demand can be reduced through structural optimisation. A major drawback from optimised design, however, is the cost and complexity of producing conventional rigid moulds. Fabric formwork is emerging as a new method for construction, gaining popularity among architects and engineers for the opportunity to build unique forms and to shape concrete elements efficiently. Porous fabrics, acting as controlled permeability formwork, also have proven effect on the durability characteristics of concrete. While fabric formwork has a profound potential to change the appearance of concrete structures, the shapes cast in fabrics are not defined in advance and have been often created unintentionally. The design of load-bearing reinforced concrete structures, however, requires accurate form-prediction and construction methods for securing steel reinforcement inside flexible fabrics, which presents a number of constructability challenges. For example, cover formers cannot be used to ensure adequate thickness of protective cover, inevitably affecting the acceptance of such structures in practice. This research has demonstrated that non-corrodable FRP reinforcement can be incorporated more easily than steel bars in fabric-formed concrete due to its light weight and flexibility, while it is possible to ensure ductility of such structures through confinement of concrete using FRP helices. A novel splayed anchorage system has been developed to provide end anchorage for optimised sections where standard bends or hooks cannot fit. This work also provides an experimentally verified methodology and guidance for the design and optimisation of fabric-formed elements.

Une demande croissante en matériaux utilisés pour la protection contre les coups de couteau a été formulée pour apporter plus de protection, flexibilité et légèreté. Les chercheurs se sont principalement concentrés sur les études relatives à la résistance aux coups de couteau des gilets pare-balles souples à base de fibres textiles et de tissus techniques 2D. Cependant, les matériaux de protection souples basés sur des tissus 3D ont rarement été étudiés dans les travaux de recherche récents, en particulier ceux qui révèlent que les architectures tissées en 3D peuvent jouer un rôle décisif lors d'un impact de couteau. Les tissus 3D interlock chaine (3DWIFs) peuvent également être utilisés dans un gilet souple pour des applications anti-poignard. L'objectif général de ces travaux de recherche actuels est d'explorer les différentes conceptions de tissus 3D interlock chaine (3DWIF) qui offrent la solution de protection la plus efficace. Par conséquent, cette thèse s'est concentrée sur les paramètres du processus de fabrication et les paramètres des produits résultants des tissus 3DWIF fabriqués avec des fils HMWPE. Les paramètres du processus de production ont été étudiés afin d'optimiser la fabrication et les propriétés mécaniques des tissus 3DWIF. Les paramètres produit des tissus 3D interlock chaine ont été étudiés afin de trouver la combinaison optimisée pour la meilleure résistance de protection contre les coups de couteau. Les quatre principales catégories d'architectures de tissus 3D interlock chaine, tels que : A/T, A/L, O/T et O/L, ont été tissées avec les mêmes fils retordus de polyéthylène à haut poids moléculaire (HMWPE). Les caractéristiques mécaniques des tissus 3D interlock chaine (3DWIF) ont été systématiquement testées et comparées. En outre, une étude expérimentale spécifique a été réalisée sur des tissus 3D interlock chaine soumis à un impact à faible vitesse, y compris les propriétés à simple et double passe en termes de profondeur de pénétration et de traumatisme. Les tests de double passage au couteau sont complémentaires des tests de simple passage au couteau. Il a été conclu expérimentalement que le tissu 3D interlock chaine de type orthogonal à liage à travers l'épaisseur a une bonne résistance aux coups de couteau. Entre-temps, les liens entre la résistance aux coups de couteau, les propriétés physiques et les propriétés mécaniques des 3DWIF ont été analysés
An increasing demand for materials used for stab protection has been expressed to provide more protective, flexibility and lightweight. Researchers have mainly focused on studies about stab resistance of soft body armour based upon technical textile fibres and 2D fabrics. However, the soft protective materials based on 3D fabrics have been rarely study in recent research works, especially those revealing that 3D woven architectures can play a decisive role during stab impact. 3D warp interlock fabrics (3DWIFs) can be used in a soft vest for anti-stab applications. The overall aim of this current research has been oriented to explore different design of 3DWIFs that provide the more efficient protective solution. Hence, this thesis has been concentrated on both the manufacturing process parameters and the resulted product parameters of the 3DWIFs made with HMWPE yarns. The production process parameters have been studied to optimize the manufacturing and the mechanical properties of 3DWIFs. The product parameters of 3DWIFs have been investigated to find the optimized combination for the best protective resistance against stabbing. The four main categories of 3D warp interlock fabrics architectures as : A/T, A/L, O/T, and O/L, were woven by twisted high molecular weight polyethylene (HMWPE) yarns. The mechanical characteristics of 3DWIFs were systematically tested and compared. Besides, a dedicated experimental study has been performed on 3DWIFs submitted to low-speed impact, including single-stab and double-stab properties in terms of depth of penetration and trauma. The double-pass stabbing tests are complementary to single-pass stabbing tests. It was experimentally concluded that the orthogonal/through-the-thickness interlock fabric has a good stab resistance. Meanwhile, the links among stab resistance, physical properties, and mechanical properties of 3DWIFs have been analysed

RTM6 has for more than 20 years been the main commercial epoxy system for infusion processing qualified by the aerospace industry. In common with other aerospace-grade epoxy systems RTM6 is mechanically strong but brittle, producing carbon-fibre (CF) composites with relatively low impact resistance and damage tolerance. This thesis reports an approach to toughening epoxy-CF composites without modification of the resin. Thus, a T300 carbon fabric (ES-fabric) coated with 20 weight % of a poly (aryl ether ketone) (PAEK) was used to toughen the composite. The initial stage of the study was the manufacturing process. DSC and oscillatory-shear rheology were used to determine flow times and cure conditions, and to produce laminates with fibre volume fractions ≥55% a hybrid resin infusion/hot-press process was developed. Dynamic mechanical thermal analysis also showed that the PAEK coating produced relatively little plasticization of the epoxy matrix, with values of the matrix glass transition temperature shifting from 186±4.4 to 181± 1.4 ºC when using the ES-fabric. The main body of the study focussed on the toughening effect afforded by the PAEK coating relative to an uncoated fabric system as a reference. Mode I and Mode II interlaminar fracture toughness behaviour were studied using dual cantilever beam (DCB) and four-point end-notch flexure (4ENF) tests, respectively. The measured mode-I fracture energy, GIC, increased three-fold, from 216 ± 7.2 Jm-2 to 751 ± 105 Jm-2, due to the toughening effect of the PAEK coating; whereas the mode-II fracture energy, GIIC, increased almost four-fold from 857 ± 99 Jm-2 to 3316 ± 372 Jm-2. Damage resistance was studied using low-velocity impact testing and damage tolerance using a miniature compression-after-impact (CAI). A comparative study of damage tolerance was performed using open-hole compression (OHC) testing. The impact damage resistance significantly improved with the use of the PAEK-coated ES-fabric as well as the CAI and OHC behaviour. Impact testing showed the PAEK -toughened system exhibited higher energy abortion than the untoughened system, larger damage area was created in the T300/RTM6-2 after impacted with same energy. The CAI results indicated that the normalized CAI strength is major related that damage width rather than other factor. OHC results are predicted by using W-N criteria, for ES/RTM6-2: ASC a0 = 9.35 mm and PSC d0 = 2.72mm; whereas for T300/RTM6-2: ASC a0 = 7.95 mm and PSC d0 =2.43 mm, indicates that the compressive strength of T300/RTM6-2 is more sensitive to the size of the hole, thus ES/RTM6-2 perform better damage tolerance. The results from mechanical testing indicate that the PAEK coating toughened the composite system and significantly improved damage tolerance. Scanning electron microscopy indicated that these improvements in fracture behaviour were due to morphological changes induced by the PAEK coating in the matrix-CF interfacial region, where such changes can provide the maximum benefit. Small particles of RTM (approximately 1 µm in diameter) were observed imbedded within a continuous PAEK phase. Thus, during testing crack propagation was deflected (or bifurcated) by the RTM6 particles or stopped by shearing of the continuous PAEK phase of this multiphase region. This morphology is proposed to have formed in the interfacial region during processing by dissolution of the PAEK coating within the matrix resin system, followed by reaction-induced phase separation and then phase-inversion as the matrix cures.

The current state of North America’s infrastructure system is in dire straits. The cost of repair is estimated at over $3.6 trillion in the United States alone. An innovative and cost-effective method of repair and retrofitting is vital to close what has been referred to as the infrastructure gap. As an alternative to the current methods, fabric reinforced cementitious mortar (FRCM) is proposed to aid the civil engineering industry in removing this gap. Applied to structural members externally, FRCM is characterized by its ability to strengthen and rehabilitate these structures. This study set out to determine the flexural strength improvement of reinforced concrete (RC) beams with different reinforcement ratios, textile layers, fabric materials and anchorage methods. Ten full-scale (200 x 300 x 4000mm) RC beams (2 controls, 8 strengthened) were cast and tested under monotonic four-point bending conditions. Ultimate flexural capacity, pseudo-ductility, energy absorption, stiffness, and failure mode were taken as performance indicators. Results showed all FRCM strengthened beams failed in a similar way to their control counterparts and FRCM did not affect the pre-yielding stiffness or ductility of the strengthened beams. However, FRCM significantly improved the beams’ yield load and flexural capacity over the control. Flexural strength improved by up to 81% over the control. Strength improved with an increase in textile layers, and U-shaped strengthened specimens outperformed their soffit-strengthened equivalents.
Applied Science, Faculty of
Engineering, School of (Okanagan)
Graduate

Reinforced concrete shear walls as seismic force resisting systems may experience inelastic deformations if subjected to strong seismic excitations. These walls are designed to provide strength, stiffness, energy dissipation capacity and lateral drift control for seismic resistance. Shear wall deformability is largely dependent on adequate confinement of core concrete in boundary elements, prevention of longitudinal bar buckling, as well as proper design and detailing of the web section. Conventional transverse reinforcement placed in shear wall boundary elements consists of hoops, overlapping hoops and crossties, based on the geometry and number of longitudinal bars used. The confinement steel requirement of current building codes (ACI 318 or CSA A23.3) often results in congestion of steel cage due to the high transverse reinforcement ratio required. Placing multiple hoops with 135-degree bends combined with crossties to satisfy the code confinement requirements can create concrete placement and construction problems. In addition, the required time to assemble conventional steel cages with multiple individual ties per spacing can be time consuming, potentially impacting the overall cost and duration of construction. Welded Wire Reinforcement (WWR) is available in the construction industry as concrete reinforcement in the form of welded wire fabric (WWF) manufactured from relatively small diameter wires in comparison to the bar sizes typically used in structural applications. As an alternative to using conventional transverse hoops, prefabricated WWR grids can be used to provide required transverse reinforcement in boundary elements. WWR grids are manufactured using robots to weld cut steel pieces accurately before they are shipped to the job site, resulting in better construction quality and reduced construction time. However, research on the use of WWR is limited in the literature. Further experimental and analytical research is needed to establish design requirements for such reinforcement, especially when used in earthquake resistant construction with requirements for ductile response. The current research project, involved three main phases; i) tests of 3 large-scale reinforced concrete shear walls with WWR grids used as boundary element transverse reinforcement, ii) material tests of grid samples, including those cast in concrete, iii) non-linear finite element analysis. The wall tests were conducted under slowly-applied lateral deformation reversals to investigate their strength and ductility for suitability as seismic resistant structural elements. Material tests were conducted to have a better understanding of WWR behavior, especially their weld capacity. Analytical research was undertaken to expand the experimental findings on shear wall behavior, as well as to conduct parametric investigation to understand the impact of changes in grid strength and ductility. The results indicated that WWR grids can be used as boundary element transverse reinforcement in earthquake resistant shear wall. However, strength and ductility of grids should be established carefully prior to such application. Design strength of WWR grids should be established through burst tests to ensure ductile yielding of wire reinforcement prior to premature weld failure. Those grids that exhibit weld failures may be used with reduced design strength to permit the development of sufficient inelastic deformability in flexure-dominant shear walls.

La technique de renforcement par geosynthetique est de part sa simplicite et son cout modere de mise en uvre, tres utilisee de part le monde et plus particulierement dans le domaine de la geotechnique et de l'environnement. L'extension de son domaine d'application aux murs de soutenement renforces et sollicites localement en tete par des surcharges (fonction porteuse) est a ce jour freinee par le manque d'ouvrages de reference et le peu de methodes de dimensionnement justifiees et validees. Pour apprehender les mecanismes de rupture et les comportements sous charges de service et a la rupture de ce type d'ouvrage, des essais en vraies grandeurs ont ete realises dans le cadre d'un projet (garden) regroupant plusieurs laboratoires. Une modelisation elements finis est proposee pour simuler le comportement des ouvrages renforces et la comparaison avec l'experimentation est riche d'enseignement. Deux logiciels de calcul ont ete utilises a titre de comparaison et de validation. En depit des differences entre les resultats theoriques et experimentaux, les mecanismes obtenus restent assez proches de ceux observes sur les deux massifs experimentaux. Une etude parametrique egalement effectuee, a permis de degager des remarques interessantes quant a la comprehension de certains comportements observes sur site

The purpose of this research is to evaluate and compare the structural performance of composite floor slabs reinforced with 6 x 6 W1.4/W1.4 welded wire fabric (WWF) and STRUX 90/40 synthetic macro fibers. Slabs were subjected to flexural strength tests and concentrated load tests while monitoring load, steel deck strains, and deflections. Test results obtained from this test program were also compared to results from a similar test program conducted in 2001. Tests were also performed to obtain the average residual-strength of the fiber-reinforced concrete using the ASTM C 1399 (2003) standard test. All slabs were loaded until a complete failure was observed. The observed failure loads were compared to failure loads calculated by design guides published by the American Society of Civil Engineers (ASCE) and the Steel Deck Institute (SDI). The flexural strength tests showed that composite slabs reinforced with synthetic macro fibers and WWF exhibited strength and behavior that was almost identical. The observed values of strength were also within the range that was predicted by ASCE prediction models. At a typical office design load of 70 psf, all slabs exhibited midspan deflections that were much smaller than those necessary for serviceability requirements. The concentrated load tests also showed that the observed strength of all composite slabs tested was above those values predicted by ASCE and SDI models. However, an effective comparison between the WWF-reinforced and synthetic macro fiber-reinforced slab was difficult due to a poor shear bond in the latter slab prior to testing. The results of the ASTM C 1399 test verified the ability of concrete reinforced with synthetic macro fibers to meet average residual-strength values recommended by the SDI.
Master of Science

The present research aims to develop a novel technique for creation of composite riot helmet shells with reinforcing fibre continuity for better protection against low velocity impacts. In this research an innovative, simple and effective method of making a single-piece continuously textile reinforced helmet shell by vacuum bagging has been established and discussed. This technique also includes the development of solid collapsible moulding apparatus from non-woven fibres. Angle-interlock fabric due to its good mouldability, low shear rigidity and ease of production is used in this research. Several wrinkle-free single- piece composite helmet shells have been manufactured. Low-velocity impact test on the continuously reinforced helmet shells has been carried out. For this purpose an in-house helmet shell testing facility has been developed. Test rig has been designed in such a way that the impact test can be carried out at different locations at the riot helmet shell. Low-velocity impact test has been successfully conducted on the developed test rig. The practical experimentation and analysis revealed that the helmet shell performance against impact is dependent on the impact location. The helmet shell top surface has better impact protection as compared to helmet shell side and back location. Moreover, the helmet shell side is the most at risk location for the wearer. Finite Element models were created and simulated in Abaqus software to investigate the impact performance of single-piece helmet shells at different impact locations. Models parts have been designed in Rhinoceros software. Simulated results are validated by the experimental result which shows that the helmet top position is the safest position against an impact when it is compared to helmet back and helmet side positions.

Devant les difficultes essentiellement administratives et sociales posees par l'ouverture de nouveaux sites de stockage de dechets, la tendance actuelle est a l'extension laterale ou verticale de centres existants, conduisant parfois a l'adoption de geometries de pente inhabituelles pour lesquelles la stabilite des systemes geosynthetiques d'etancheite en pente (sur talus ou en couverture) devient une question cruciale. La maitrise de la stabilite de tels systemes passe par une meilleure comprehension de leur fonctionnement. Dans ce but, l'etude de la caracterisation sur plan incline des interfaces geosynthetiques a ete menee, ainsi que celle du renforcement par inclusion de geosynthetique et l'analyse de la reponse d'un systeme geosynthetique d'etancheite en vraie grandeur. Cette etude se base principalement sur des essais de laboratoire realises sur un dispositif plan incline elabore dans le cadre de ce travail. La validite de la caracterisation sur plan incline des interfaces sable/geosynthetiques est confirmee par la repetabilite, la reproductibilite et la coherence des caracteristiques d'interface obtenues vis-a-vis des tendances generales observees en boite de cisaillement direct, relatives a l'influence du confinement. Le mecanisme d'ancrage constitue le principe de base du renforcement par inclusion de geosynthetique. Les essais de renforcement realises montrent particulierement une meilleure efficacite du renforcement par inclusion pour stabiliser le sol de couverture, par rapport au renforcement classique a la base du sol. L'analyse des donnees issues d'une experimentation en vraie grandeur sur un systeme geosynthetique d'etancheite illustre particulierement la difficulte de prediction du fonctionnement d'un systeme reel, due principalement aux incertitudes de la mise en place.

Le renforcement des sols au moyen des geosynthetiques est en constante evolution. Cette technique, de part sa simplicite et son cout de mise en oeuvre modere, a deja atteint une certaine reconnaissance pour differentes applications telles que les murs de soutenement renforces (porteur ou non). Un programme de recherche (r. A. F. A. E. L. ) regroupant differents organismes (sncf, scetauroute, bidim geosynthetic s. A. , lrpc, lirigm) a ete mis en oeuvre pour developper une technique de renforcement par geosynthetiques sous les assises ferroviaires et autoroutieres dans les zones a risque. Des remblais experimentaux en vraie grandeur, sollicites par des effondrements localises, ont ete realises sur le site experimental d'eurre (drome) pour contribuer au developpement d'une methode de calcul appropriee a ce type de renforcement. Le dimensionnement des differentes structures experimentales, a pu se faire grace au developpement d'une formulation numerique originale en trois dimensions, d'un element de nappe textile par la methode des elements finis. Des etudes parametriques portant sur la nature du textile, du sol et des conditions d'ancrage sont presentees pour justifier des dispositions techniques retenues. La comparaison des resultats experimentaux et des calculs previsionnels, est tout a fait satisfaisante et montre les avantages et les limites d'une telle solution de renforcement.

The task performed in this assignment is to improve the reliability of Norden Machinery ABs product family. This is to be done by examining and replacing the belt used to stop the spreading of tubes from ingoing shipping crate to the infeed of the machine. The way that this was approached was by testing different candidates on a spectrum of their rigidity to find if a flexible or more rigid belt would perform better than the current context of the system. The testing was conducted for a period of 4 weeks and results were gathered by examining damages to the belts by the use of microscope. After the damage had been analyzed the conclusion was drawn that flexible alternatives seems to perform the task better than their rigid counterparts however more work is needed in the fields regarding the fastening and operation of the machine to use the best suited candidates derived from this test, the monolithic belt FMT-02TXCT-U1.

Zu Beginn des Forschungsvorhabens wurden im Rahmen der Teilprojekte B1 und B2 des SFB 532 alkalibeständige Glas- und Carbonrovings eingesetzt, die zu offenmaschigen 2D-Textilien verarbeitet wurden. Untersuchungen des Verbund- und des Tragverhaltens der Verstärkungsstrukturen in Pull-Out- und Dehnkörperversuchen haben gezeigt, dass das Potential der Verstärkungsfasern aufgrund einer unvollständiger Durchtränkung der Bewehrung nicht vollständig ausgeschöpft werden kann. Auch Defizite bei der Produktionstechnik wurden erkannt und für zukünftige Entwicklungen analysiert. Um das Potential der verwendeten Verstärkungsfaser vollständiger auszuschöpfen, wurden innovative Garnkonstruktionen, die sich positiv auf den inneren und/oder den äußeren Verbund auswirken, entwickelt und erprobt. Anhand von Versuchsreihen auf der Textilebene wurden unterschiedliche Textilparameter, wie Art der Bindung, Gittergröße und Wirkfadenspannung, identifiziert, die unmittelbar die Tragfähigkeit der Verbundbauteile beeinflussen. Für die gängigen Produktionstechniken Laminieren, Gießen, Spritzen, Schleudern und Extrudieren wurden entsprechende Bewehrungskonstruktionen abgeleitet, die den Anforderungen des jeweiligen Prozess angepasst wurden. Ein weiterer Punkt der Forschungsaktivitäten stellte die Entwicklung der Maschinentechnik zur Herstellung von Verstärkungstextilien dar. Am Institut für Textiltechnik (ITA) der RWTH Aachen University wurde in Zusammenarbeit mit Industriepartnern ein Maschinenkonzept entwickelt und umgesetzt, das die Herstellung von 3D-Abstandsgewirken mit einer freien Gestaltung der Deckflächen mit marktrelevanten Produktionsgeschwindigkeiten ermöglicht. Zur gezielten Einstellung der Wirkfadenspannung wurde ein Regelungssystem konzipiert und technisch umgesetzt, mit dem eine reproduzierbare Fertigung von textilen Verstärkungsstrukturen möglich wird.

Dans le cadre de cette thèse, une modélisation par éléments finis continue renforcée discrète est développée. Le modèle est basé sur le concept de la cellule élémentaire, avec utilisation de connecteurs pour prendre en compte la rigidité en tension de la structure, et modéliser l'anisotropie du tissu et un élément coque pour décrire la rigidité en cisaillement et gérer le frottement et le contact avec les outils lors de la simulation du procédé de préformage. Les différents éléments de ce maillage spécifique sont générés automatiquement à l'aide des scripts pythons. Associés à ce choix de modélisation, les caractéristiques du comportement sont déterminées à l'aide d'essais expérimentaux conduits sur le renfort et d'une démarche de méthode inverse. Le comportement de ces différents éléments est choisi d'être linéaire élastique en premier lieu, et par la suite à évoluer pour devenir non linéaire. Ces développements numériques sont réalisés dans le logiciel Abaqus/ Explicit. Dans un second temps le modèle développé est utilisé dans le cadre de simulation de l'étape de préformage des renforts secs. A ce titre un démonstrateur expérimental développé dans le cadre de la thèse sert à obtenir des résultats expérimentaux pour corréler ces travaux de simulations. Des comparaisons avec des simulations mono-couche, hémisphérique, permettre de mettre en évidence l'influence des paramètres de simulations mises en jeu. Dans le cadre de préformages de plusieurs plis, l'influence des caractéristiques du contact / frottement est mise en évidence. Finalement une procédure d'automatisation afin de rendre la simulation plus ergonomique dans un contexte industriel est présentée. Cette procédure consiste à générer le maillage spécifique et mettre la simulation en donné dans Catia. Les simulations peuvent ainsi se réaliser sans le passage par Abaqus/CAE.

La technique du tissage consiste à créer un entrecroisement de fils perpendiculaires entre eux. Pour cela, il est nécessaire d'insérer un fil de trame à travers une nappe de fils de chaîne parallèles. L'étape de formation de la foule, consistant à séparer la nappe de chaîne pour libérer un espace d'insertion, est vecteur d'interactions interfilamentaires et de dommages induits dans la structure filamentaire. Un tel phénomène, rapporté au tissage de renforts de matériaux composites produit des dégradations de structure importantes et une diminution sensible des propriétés mécaniques du produit fini. Dans le contexte de la croissance du marché des matériaux composites haute performance à renforts tissés, il est nécessaire d'améliorer puis de maîtriser le procédé de tissage. Ainsi, pour optimiser le tissage d'étoffes multicouches à haute densité, nous disposons d’une machine Jacquard. Il s'agit d'une technique qui permet un pilotage individuel motorisé des fils de chaîne et qui offre des paramètres de foule particuliers. Le but de ces travaux sont d'étudier ces paramètres d'une part et de définir et analyser leurs effets sur le processus de tissage par ailleurs. Nous utilisons pour ces travaux du polyester multifilamentaire, ainsi qu'un dispositif de tissage particulier adapté au tissage technique multicouches. Nous constatons que le tissage multicouches de forte densité génère de nombreux frottements interfilamentaires qui dégradent les fils en provoquant de la fibrillation. L'observation de l'évolution de ce phénomène selon les différents paramètres Jacquard, permet tout d'abord de mieux le comprendre et le cerner. Elle permet ensuite de déterminer les configurations de tissage optimales pour assurer la qualité du tissage de renforts tissés
Weaving basic structure is an orthogonally interlaced yarns plane, produced thanks to weft insertion across parallel warp yarns. Shedding is a major step for shed generation by warp yarns separation. Shedding may generate warp yarns interactions and yarn structure degradations because of density. Such a phenomenon becomes major with composite high density woven reinforcement where degradations and final product mechanical properties loss may become considerable. With high performance composites market growth, weaving process needs to be improved.A Jacquard shedding mechanism has been employed for high density multilayer woven fabric weaving optimization, as this technique enables warp yarns individual motorized driving with very particular shedding parameters. In this research, Jacquard shedding parameters have been studied so that their effects on the weaving process may be brought to light, with a specific weaving machine dedicated to multilayer weaving, where polyester multifilament yarns are used.It has been observed that high density multilayer weaving produces friction and many degradations during shedding between filaments because of the fibrillation phenomenon. Fibrillation has been examined and understood thanks to the observation of its evolution according to Jacquard shedding parameters. It has been the basis for optimal weaving parameter configurations which may be used for woven reinforcements composites quality improvement

Dimensionierung und Konstruktion von Bewehrungstextilien für die Anwendung in Textilbeton werden in Abhängigkeit von der resultierenden Last im Bauteil durchgeführt. Um aus der Vielzahl möglicher Varianten von Bewehrungsstrukturen die passenden auszuwählen, wird ein reduziertes Beschreibungsschema zur Auswahl herangezogen. Als Anwendungsbeispiel wird eine komplexe Bewehrungsstruktur beschrieben, die für dünnwandige, selbsttragende Sandwichelemente genutzt wird. Die Sandwichelemente werden als Wandund Dachkonstruktion für ein 20 m² großes modulares Gebäude eingesetzt. Die Bewehrungsstrategie für die Elemente sowie die Herstellungstechnik und Prüfverfahren für die Bewehrung werden beschrieben. Zur Langzeitüberwachung der Sandwichelemente wird ein Monitoring-System verwendet.

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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior
As most current studies, reinforced plastics have been, in recent years, a viable alternative in building structural elements of medium and large, since the lightness accompanied by high performance possible. The design of hybrid polymer composites (combination of different types of reinforcements) may enable structural applications thereof, facing the most severe service conditions. Within this class of composite materials, reinforced the underlying tissues hybrid high performance are taking space when your application requires high load bearing and high rigidity. The objective of this research work is to study the challenges in designing these fabrics bring these materials as to its mechanical characterization and fracture mechanisms involved. Some parameters associated with the process and / or form of hybridization stand out as influential factors in the final performance of the material such as the presence of anisotropy, so the fabric weave, the process of making the same, normative geometry of the specimens, among others. This sense, four laminates were developed based hybrid reinforcement fabrics involving AS4 carbon fiber, kevlar and glass 49-E as the matrix epoxy vinyl ester resin (DERAKANE 411-350). All laminates were formed each with four layers of reinforcements. Depending on the hybrid fabric, all the influencing factors mentioned above have been studied for laminates. All laminates were manufactured industrially used being the lamination process manual (hand-lay-up). All mechanical characterization and study of the mechanism of fracture (fracture mechanics) was developed for laminates subjected to uniaxial tensile test, bending in three and uniaxial compression. The analysis of fracture mechanisms were held involving the macroscopic, optical microscopy and scanning electron microscopy
Conforme estudos mais atuais, os pl?sticos refor?ados v?m sendo, nos ?ltimos anos, uma alternativa vi?vel na constru??o de elementos estruturais de m?dio e grande porte, desde que a leveza acompanhada de alto desempenho seja poss?vel. A concep??o de comp?sitos polim?ricos h?bridos (combina??o entre tipos diferentes de refor?os) pode possibilitar aplica??es estruturais dos mesmos, frente ?s mais adversas condi??es de servi?os. Dentro dessa classe de materiais comp?sitos, os refor?ados a base de tecidos h?bridos de alto desempenho v?m tomando espa?o quando a sua aplica??o requer alto suporte de carga e alta rigidez. O objetivo desse trabalho de investiga??o ? o estudo da influ?ncia que esses tecidos trazem na concep??o desses materiais quanto a sua caracteriza??o mec?nica e mecanismos de fratura envolvidos. Alguns par?metros associados ao processo e/ou forma de hibridiza??o se destacam como fatores influenciadores no desempenho final do material tais como a presen?a de anisotropia, forma da trama tecido, processo de confec??o dos mesmos, geometria normativa dos corpos de prova, entre outros. Neste sentido, quatro laminados comp?sitos foram desenvolvidos ? base de tecidos de refor?os h?bridos envolvendo fibras de carbono AS4, kevlar 49 e vidro-E e como matriz a resina ep?xi ?ster vin?lica (DERAKANE 411-350). Todos os laminados comp?sitos foram constitu?dos com quatro camadas de refor?os. Dependendo do tipo de tecido h?brido, todos os fatores influenciadores acima mencionados foram estudados para os laminados. Todos os laminados foram fabricados industrialmente sendo empregado o processo de lamina??o manual (hand-lay-up). Todo o estudo da caracteriza??o mec?nica e do mecanismo de fratura (fratura mec?nica) foi desenvolvido para os laminados submetidos aos ensaios mec?nicos de tra??o uniaxial, flex?o em tr?s e compress?o uniaxial. As an?lises dos mecanismos de fratura foram realizadas envolvendo a macroscopia, microscopia ?tica e eletr?nica de varredura

Les CMC oxyde/oxyde sont de bons candidats pour des applications thermostructurales. Le comportement mécanique et les mécanismes d’endommagement de deux composites alumine/alumine à renforts tissés bi- et tridimensionnels ont été étudiés et comparés. La microstructure de ces CMC à matrice faible a été caractérisée à partir de porosimétrie et de CND, tel que thermographie IR, scan ultrasonore et tomographie X, ce qui a permis de mettre en évidence la présence de défauts initiaux. Le comportement mécanique en traction, ainsi qu’en compression dansle cas du CMC à renfort bidimensionnel, dans la direction des fibres ainsi que dans la direction ±45°, aété étudié à température ambiante. Afin d’exploiter pleinement ces essais, nous avons eu recours à plusieurs méthodes d’extensométrie et de suivi d’endommagement, telles que la thermographie IR et l’émission acoustique. Les propriétés mécaniques à rupture ainsi que le module de Young du CMC à renfort bidimensionnel développé à l’Onera se sont avérées supérieures à celles disponibles dans la littérature. Les mécanismes d’endommagement des matériaux ont été déterminés à partir d’observations post mortem au MEB et d’essais in situ dans un MEB, ce qui a permis d’évaluer la nocivité des défauts initiaux. Enfin, l’étude du comportement mécanique de ces composites a permisde proposer un modèle d’endommagement tridimensionnel qui permettra de poursuivre le développement de ces matériaux grâce à du calcul de structure. A l’issue de cette thèse, des pistes d’amélioration des procédés d’élaboration et de choix d’instrumentation à utiliser pour les futures études, notamment en ce qui concerne le suivi d’endommagement, ont également été proposées
Oxide/oxide CMCs are good candidates for thermostructural applications. Themechanical behaviour and damage mechanisms of two alumina/alumina composites with two andthree dimensional woven reinforcements were studied and compared. The microstructure of theseweak matrix CMCs was characterized by porosimetry and NDT methods, such as IR thermography,ultrasound scanning and X-ray tomography, which highlighted initial defects. The mechanicalbehaviour was studied through tensile tests, as well as compression tests in the case of the twodimensionalreinforced CMC. These tests were conducted at room temperature, in the fibres directionsand in the ±45° direction. In order to fully exploit these tests, several extensometry and damagemonitoring methods, such as IR thermography and acoustic emission, were used. Young’s moduli andmaximum stresses and strains of the two-dimensional reinforced CMC developed at Onera appearedto be higher than those available in the literature. The damage mechanisms of the materials weredetermined by post mortem SEM observations and in situ testing in a SEM, which made it possible toassess the nocivity of initial defects. Studying the mechanical behaviour of these composites finallyenabled the development of a three-dimensional damage model that will facilitate the furtherdevelopment of such materials, through finite element analysis. Finally, some improvements regardingthe manufacturing processes and the instrumentation for damage monitoring were suggested forfuture studies

碩士
國立中興大學
土木工程學系
85
Abstract The purpose of this study is to investigate the flexural behaviorof concrete columns with welded wire fabric as shear reinforcement under constant axial load and cyclic lateral load . A total of ten column specimens were made in this study . The size of specimens was300mm×300mm×4500mm . The variables included were concrete strength、loading type、amount of transverse reinforcement、type of transversereinforcement、level of axial load and arrangement of transverse reinforcement . The results showed that strengths predicted by ACI Code were conservative . Cyclic loading on column would not reduce the maximumstrength but would reduce the ductility tremendously . Flexural strength、 ductility、crack control、strength and stiffness degradation of columns with welded wire fabric were about the same as columns withconventional transverse reinforcement . Capability of energy dissipationof columns with WWF was higher than that of conventional columns .WWFcan be adopted in concrete columns due to its construction ease .

碩士
國立中興大學
土木工程學系
84
The purpose of the study is to investigate the shear strength of reinforced concrete beams with welded wire fabric as shear reinforcement under cyclic loading. A total of thirteen beam specimens were made. Twelve specimens contained welded wire fabric while the other one contained conventional shear reinforcement. The parameters included concrete strength, shear span to depth ratio, amount of tension reinforcement, ratio of negative steel to positive steel and amount of shear reinforcement. The results show that shear strengths at cracking of beams with welded wire fabric are larger than those of beams with conventional shear reinforcement, while ultimate shear strengths of both type of beams are about the same. Beams with welded wire fabric showed better crack control than beams with conventional shear reinforcement. Cracking strength and ultimate strength of beams under cyclic loading are much lower than those of beams under monotonic loading. The ACI provisions apply if the upper limit of 60000 psi design shear strength is still valid.

碩士
國立中興大學
土木工程學系
84
Abstract The purpose of this study is to investigate the flexural behavior of reinforced concrete beams with welded wire fabric as shear reinforcement under cyclic loading. Atotal of fourteen beam specimens were made. Twelve contained welded wire fabric as shear reinforcement while the other two contained conventional shear reinforcement. The parameters included concrete strength, shear span to depth ratio, spacing of shear reinforcement, ratio of positive steel to negative steel, amount oftension reinforcement and loading history。 The results show that beams with welded wire fabric have less ductility than beams with conventional shear reinforcement. Beams with WWF have better crack control than those with conventional shear reinforcement. Beams with WWF showed faster deterioration than those with conventional shear reinforcement in strength and stiffness. Increase of amount of shear reinforcement and negative steel will increase the energy dissipation capacity。

碩士
國立中興大學
土木工程研究所
86
The purpose of this study is to investigate the shear behavior of concrete columns with welded wire fabric (WWF) as shear reinforcement under cyclic loading. A total of twelve column specimens were made in this study. Eleven of the specimens contained WWF while the other one contained conventional shear reinforcement. The variables included in this study were concrete strength, shear span ratio, axial load, anchorage of ties, amount of shear reinforcement and loading type. 　　The results showed that the ultimate shear strengths of columns with WWF were higher than that of conventional column. Both strengths at cracking and ultimate of columns increased with concrete strength, axial force, while reducing shear span ratio increased the shear strengths. Cyclic loading reduced the shear strengths tremendously. Efficiency of WWF shear reinforcement was higer than conventional shear reinforcement. Use of one longitudinal wire welded to the end of 90° hook of ties provided enough anchorage and thus may ease the construction difficulty result from the 135° hook required by current ACI Code.

An investigation has been carried out to reduce the deformation behavior of polyethylene (PE) woven geotextile fabric by making PE fabric-glass yarn composite structure using stitching and laminating. The results showed that reinforcement significantly reduced the creep and IED as long as the tensile stress is lower than the total load bearing capacity of the glass yarns in the composite structure. However, the strength of PE-glass composite fabric was solely dependent on the strength of the glass yarns. The strength from PE yarns only contributes when all glass yarns are broken. Cast result of concrete columns using the glass yarn reinforced PE fabric by stitching method suggested that the glass yarn must face outside of the fabric formwork to avoid damage of both fabric surface and column surface.

L’utilizzo di sistemi FRCM si sta progressivamente affermando in campo ingegneris- tico come promettente tecnica per il rinforzo e la riabilitazione di strutture in cemento e in muratura. Tuttavia, a causa della mancanza di documentate informazione sulle prestazioni nel tempo di questi materiali compositi, ad oggi poco è noto della loro capacità di resistere all’esposizione a diversi ambienti potenzialmente aggressivi. La complessità nello studiare i diversi meccanismi responsabili per il deterioramento di questi sistemi nel tempo è data dai diversi tipi di stress ambientale a cui il materiale può essere esposto durante la sua vita di servizio, così come dall’ampia varietà di materiali che possono essere impiegati. Inoltre, per rinforzi modificati con coating organici o inorganici, spesso proposti in letteratura per aumentare le capacità di carico del composito, le performance complessive del sistema saranno influenzate dal tipo di coating applicato. Lo scopo principale di questo studio è verificare come diverse tecniche, proposte in letteratura per la modifica dei rinforzi in rete, influenzino la capacità degli FRCM di mantenere inalterate le proprie proprietà meccaniche a seguito dell’esposizione a diversi ambienti. Inoltre, al fine di ottimizzare sia le proprietà meccaniche che la durabilità del composito, è stato studiata l’efficacia di coating a base stirene-butadiene contenenti diverse percentuali di nano argille. I rinforzi in fibra presi in considerazione in questo studio comprendono sia fibre in carbonio che in vetro, le prime note per godere di un ottima stabilità chimica, le seconde soggette a corrosione in ambiente alcalino. Le fibre in carbonio sono state modificate con una soluzione ossidativa, un coating epossidico e un a base di nano silice. L’efficacia dei coating con nano argille è stata studiata su fibre in vetro alcalino resistente appositamente filate per questo progetto al Leibniz Institute für Polymerforschung (IPF) di Dresda, dove è stato condotto parte di questo lavoro. Come caso studio di sistemi commercialmente disponibili si è fatto uso di un rinforzo in fibra di vetro preapprettato con coating stirene-butadiene. I protocolli d’invecchiamento accelerato adottati comprendo: immersione dei provini in soluzioni alcaline e saline ed esposizione a cicli gelo-disgelo. I test sono stati eseguiti sia sul materiale composito che su i suoi componenti (matrice e rete in fibra). L’effetto dei vari ambienti di esposizione sulla matrice cementizia è stato studiato tramite test a flessione e compressione abbinati a cromatografia ionica e diffrazioni a raggi X. Tensil test e pull-out test sono stati eseguiti su singoli yarn al fine di valutare l’effetto dei caoting sulle proprietà meccaniche e la durabilità del rinforzo e del materiale composito. La caratterizzazione del sistema ottenuto con la rete preapprettata è stato eseguito tramite tensile test. Per le fibre realizzate all’IPF sono stati effettuati anche test micro meccanici su filamenti singoli. Analisi FTIR, TGA, DSC, XRD, SEM-EDX e AFM sono state effettuate per la caratterizzazione dei coating e della superficie delle fibre. In generale si è potuto constatare che la stabilità chimica del rinforzo svolge un ruolo secondario nella durabilità del composito, e che sulla base del comportamento delle singole componenti non si possono trarre conclusioni sulla capacità del composito di sottostare l’esposizione a diversi ambienti. Il coating epossidico e quello a base di nano silice sono in grado sia di aumentare l’interazione delle fibre in carbonio con la matrice, che di preservare le proprietà del composito nel tempo. Per i coating contenenti nano argille, un aumento delle capacità di carico è stato osservato nelle prove di pull-out al crescere della percentuale di nano argille. Tuttavia i migliori risultati in termine d’interazione coating-matrice e durabilità del composito si ottengono per un quantitativo di nano argille pari al 5%.
Over the last decades Fabric Reinforced Cementitious Matrix (FRCM) systems have gained great interest as a promising technique for the reinforcement and rehabilitation of concrete and masonry structures. However, due to the lack of anecdotal information or documented long-term performance, at present relatively few is known about the durability of these materials under different environmental exposure. Therefore, a comprehensive understating of the different mechanisms responsible for the deterioration of FRCM systems over time is still an issue. This is due to the different kind of environmental stress that the composite may have to withstand during its life, and on the great varieties of materials (cementitious matrices and fabrics) that can be employed. Moreover, when textile are modified with some kind of coatings, as it has been proposed by different studies to improve the mechanical properties of the composite, the overall performance of the composite over time will also be affected by the different kind of coatings possibly applied. The primary aim of this work is to understand how different techniques, proposed in the literature for the modification of FRCM reinforcements, influence the ability of the composite to withstand environmental exposures. Secondary, different coatings based on a Carboxylated Styrene Butadiene (SB) polymer formulated with increasing percentage of nanoclay were investigated as modification technique to obtain a composite with improved mechanical properties and durability. Chemically stable carbon fibers as well as AR-glass fibers, which are known to undergo chemical degradation in alkaline environments, have been used. Carbon fibers have been modified with an oxidative solution, a nanosilica coating and an epoxy coating. The experimental nanoclay-SB coatings were applied on AR-glass fibers specifically spun for this project at the Leibniz Institut für Polymerforschung Dresden (IPF), where part of this work has been conducted. Durability test on commercially available reinforcements were also conducted using a Styrene Butadiene preimpregnated AR-glass fabric. Aging protocols adopted include immersion in saltwater and alkaline solution and freeze–thaw cycles. Tests were performed on both the composite material and its components. Compressive and three point bending test were employed to evaluate the change in the matrix properties after environmental exposure. Ionic chromatography and X-ray diffraction (XRD) were used to investigate possible change in the chemical composition of the matrix. Tensile test on single yarn and pull-out test were respectively employed to evaluate the effect of different coatings on the durability of the reinforcement and the composite. Characterization of the composite based on the AR-Glass commercial fabric were performed on FRCM coupons. For the IPF fibers single fiber tensile test and quasi-static single fiber pull-out test were also performed. FTIR, TGA, DSC, XRD, SEM-EDX and AFM analysis were employed for the characterization of the coatings as well as the surfaces of the modified fibers. In general, it could be observed that the chemical stability of the reinforcement plays a minor role on the durability of the composites, and that no conclusion on the ability of the composite to withstand different environmental exposure can be drawn on the base of the components’ behavior. Epoxy resin and nanosilica coatings were both found to improve the interaction of the reinforcement with the matrix and simultaneously preserve the mechanical properties of the composite over time. For the nanoclay coatings an increase in the pull-out load was observed for high amount of nanoclay. However, the best results in terms of polymer-matrix interaction and durability were obtained with the addition of 5% of nanoclay in the polymeric coating.

碩士
國立臺灣大學
國際企業學研究所
92
Composite material is made of 2 or above kinds of chemical & engineering raw material with excellent strength at a light weight. Take resin and reinforcement material for example, they can be combined into reinforcement plastics, which is one type among composite material. However, accompanying with the changing of international environment, shift abroad has become an hot issue of enterprises management in recent years and polymer composite is no exception. So far, manufacturing basement of tennis racket and golf instruments have shifted abroad, and PCB is on its way to Mainland China step by step. As a result, how to take advantage of China’s workforce, to strengthen our capability and to prevent its inanition are the serious topics to get foothold in Taiwan. Therefore, choosing fiberglass industry in Taiwan as my object of research, ranged from traditional fiberglass reinforcement plastics ( including thermoplastic and thermosetting plastics ) to electrical fabric market, there is obvious difference in price, scale and capability between fiber and fabric, which are made of glass, while the development of Taiwanese fiberglass industry has been learned. Therefore, the thesis takes the concept of Structure-Conduct-Performance (SCP) from industrial economics as a basis of my research and introduces the concepts of marketing segmentation from STP marketing, competitive strategy from Porter to be the variables of business behavior to observe both strategy and marketing positioning and realized marketing mix in order to find the difference of marketing strategy and structure between each company, to connect with their specific performance to find the difference and critical factor of the reason. Then, the last will take a further analysis to differentiate the structure, behavior, and performance between FRP and electrical fabric glass market in order to map out future development for related firms. According to conceptual logic framed in the context, empirical results show the following. 一、Marketing Structure and Strategic Behavior 1.The degree of competition between firms in electrical fabric market is mainly affected by market concentration, vertical integration, and product differentiation. 2.Marketing segmentation strategy toward both FRP & Fabric markets is not affected by the degree of competition. 3.Development of product property in marketing strategy is related to production differentiation in marketing structure. 二、Marketing Strategy and Competitive Stagegy 1.Marketing segmentation strategy is related to business competitive strategy. 2.The higher degree of production differentiation in market structure will make brand effect more critical. 三、Implement of Marketing-Mix 1.The higher degree of competition between firms will make the price more sensitive. 2.Electrical fabric firms tend to take direct-sale channel than FRP firms. 3.Both FRP & Fabric markets mainly promote through personal selling. 4.The performance of fabric firms is more sensitive to market conduct. However, FRP firms are more sensitive to marketing structure. Due to limitation on this research process conducted, some suggestions of future research are proposed to indicate a further direction for the later research.

This research includes a preliminary study prior to the commencement of the Ph.D. work and three phases of design, construction and testing of three generations of moment-shaped beams. Each phase of the research brought a better understanding of curved beams which follow the shape of the moment diagram. The moment diagram in this study was for simply supported beams supporting a uniformly distributed load as would be the case in the majority of building designs. The original theory for this research can be described as follows: Moment-shaped beams are the natural outcome of a fundamental understanding of stress paths in a horizontal load bearing member. By following these stress paths we may provide materials where required to most efficiently carry the compression and tension stresses to the supports. Allowing stresses to follow their naturally desired paths reduces regions where stresses cross paths called disturbed regions. The outcome of the final phase of this research was the development of the third generation of curved beams with a camber. These beams, designated as Cambered Curve beams (CCBs), exhibited the same behaviour as the rectangular control beam design using CSA-A23.3 up to the serviceability failure of L/360 (12mm). The CCB moment-shaped beams require 20% less concrete and 40% less reinforcing steel (no shear stirrups) to carry the ultimate load which is only 12% less than that carried by the CSA-designed control beam. Due to a closed system of internal forces, the moment-shaped beams remain intact and are able to sustain self weight, even after total failure. A significant part of this research was to modify and verify a FORTRAN-based finite element analysis program: FINIT-Y. This program was reconstructed to analyse a full size beam, and enabled the researcher to model and correctly predict the maximum load, crack pattern and failure mode. This study found that moment-shaped beams with no shear reinforcement have the same stiffness and load carrying capacity as the CSA-designed rectangular control beam with shear reinforcement up to serviceability failure (L/360). The study also found that moment-shaped beams have significantly lower ductility at the ultimate load.