Ce travail de recherche est axé sur la compréhension du comportement en flexion, statique et instantané, des structures multimatériaux acier-béton collées du génie civil. La première étape consiste à mener une analyse expérimentale et numérique par éléments finis non linéaire sur la caractérisation de la connexion. L’essai Push-Out a été retenu : deux dallettes de béton C25/30 sont connectées à un profilé métallique. Nous faisons varier la géométrie des dallettes et du joint de colle. La ruine est cohésive dans le béton proche de l’interface par cisaillement. Un effet favorable du frottement entre dallette et presse peut se développer et induire le développement de contraintes de compression et augmenter la contrainte de cisaillement moyenne à l’interface. Les dimensions des éprouvettes et du joint de colle influent sur la charge de ruine. Ainsi, l’essai Push-Out est, dans l’état actuel de connaissances, difficile à utiliser pour la caractérisation de la connexion collée acier-béton en vue du dimensionnement de structures. La seconde partie est consacrée à l’analyse du comportement de poutres mixtes acier béton collées. Un essai sur poutre constituée de prédalles et d’une dalle de compression confirme que le collage est une alternative aux connexions traditionnelles. Nous développons aussi un modèle de calcul en variables généralisées et en variables locales en 3D non linéaire. La modélisation par éléments finis apporte plus de précisions, notamment sur l’état de contraintes à proximité de l’interface et à l’approche de la ruine. Les dimensions du joint de colle et la plastification du profilé influent sur la zone de rupture dans le béton. / This PhD thesis investigates the connection of steel-flexural members by bonding and focuseson static and instantaneous behavior. First, experimental and numerical analyses are performed. A push out test is used : two concrete blocks are connected to steel members. The influence of the concrete blocks and bonding joint geometry is examined. Cohesive shear failure appears in concrete near the interface. Failure can occur when the average shear strain is twice the tension limit of concrete, which can be explained by favorable slipping between the concrete block and the support. In this case, the bonding joint is not only solicited in shear but also in compression. Results depend on the length of bonding joint and concrete blocks geometry. So, push out test cannot be now used to characterize the bonding connection between steel and concrete in order to design structures. The second is about the analysis of the behavior of steel concrete composite beams. A precast beam with compressive concrete was tested. Results show that a bonding connection can be an alternativesolution regardless of the slab manufacturing. We develop two numerical models. The first one is based on multi-layer beam modeling and the second one is a nonlinear 3D finite element model. The stress distribution close to the interface and near failure is more accurate with the finite element model than with the generalized model. Bonding joint geometry and plastification of steel girder have an influence on the failure region in the concrete.

Les planchers mixtes bois - béton sont une solution pertinente en construction neuve comme en réhabilitation. Ce travail de recherche s'inscrit dans une volonté de favoriser l'essor de la construction mixte bois - béton en France. Il vise une meilleure connaissance des phénomènes affectant le comportement mécanique ou thermomécanique de la connexion bois - béton. En comparaison de procédés constructifs traditionnels, relativement peu de recherches ont été menées concernant le comportement d'un système de connexion mixte sous conditions accidentelles de séisme et d'incendie. Ces deux points sont ici abordés via une approche expérimentale puis numérique. Dans ce contexte, plusieurs campagnes expérimentales ont été réalisées.24 essais Push Out ont été réalisés à température ambiante sur le système de connexion mixte bois-béton par tirefonds métalliques SBB. 12 essais Push Out ont suivi un chargement cyclique alterné et 12 autres ont suivi un chargement statique monotone. Les essais ont montré un comportement ductile de la connexion et une bonne résistance mécanique du système. Les essais sous chargement cyclique ont assuré de la capacité du système à dissiper de l’énergie et de quantifier la perte de résistance de la connexion sous chargement alterné. Des modèles descriptifs ont été adaptés afin de mettre en équation les courbes force-déplacement expérimentales.Afin d’étudier plus précisément les phénomènes locaux intervenant entre le bois et le connecteur, une campagne d’essais complémentaires a été menée. Elle consiste en 16 essais d’arrachement du connecteur mis en place dans du lamellé-collé et 3 séries de 16 essais en enfoncement de différentes parties du connecteur (filet, partie lisse) dans du bois lamellé-collé. La connaissance du comportement de la connexion pour ces phénomènes locaux a permis d’alimenter plusieurs modèles prédictifs (numériques et analytiques) du comportement au cisaillement de la connexion. Ces derniers présentent une bonne corrélation avec les essais Push-Out réalisés précédemment.Afin d’apprécier le comportement sous incendie des planchers mixtes bois-béton, des essais sous feu ISO 834 ont été menés. La base de données sur les essais sous incendie des planchers mixtes SBB est composée d’un essai sur plancher mixte chargé (dimensions 5.35m x 3.5m) et d’une série d’essais au cisaillement sur trois configurations différentes de connexion mixte bois-béton. Ces derniers essais fortement instrumentés en thermocouples ont permis de valider les modèles thermiques numériques également développés dans ce travail. Les modèles thermiques et thermomécaniques couplés réalisés sous Abaqus© ont permis de confirmer l’échauffement limité des connecteurs bois-béton en situation d’incendie ainsi que de quantifier les dégradations de rigidité et de résistance de ces derniers. Ainsi le comportement mixte des planchers mixtes bois-béton peut être assuré en situation d’incendie sous réserves de sections suffisantes. / Timber - concrete composite structures are competitive technical solutions for new building construction as well as in refurbishment. This work aims at promoting timber - concrete construction in France thanks to a better knowledge of mechanical and thermo-mechanical behavior of the fasteners. Regarding more traditional buildings systems, few researches were lead about seismic and fire design of timber concrete structures. Particular emphasis is put on those two points in this study through experimental, analytical and numerical approaches. As a matter of fact, several experimental campaigns were lead. 24 Push Out tests have been carried out at ambient temperature on the SBB timber-concrete composite system. The test program involved 12 Push Out tests under cyclic loading and 12 Push Out tests under monotonic loading. Experimental results brought to light the good mechanical performances as well as the large ductility reserve of SBB timber-concrete connection system. The cyclic tests have revealed the system ability to dissipate energy and allowed quantifying the loss of rigidity and resistance of the system. Descriptive models (Foschi, Dolan, Richard) have been adapted to reproduce to the experimental load-slip curves.In order to get further insight into the local phenomenon taking place between timber and the SBB connector, a second test program was devised. The tests involved 16 Pull Out tests (connector from timber) and 3 series of 16 embedment tests og various parts of the connector in glue laminated timber. Thanks to these experimental results, a better understanding of the SBB behavior has been reached. Predictive models are provided for numerical and analytical modeling of timber - concrete fasteners. Those models show good agreement with the Push Out tests introduced in previous part.In order to assess the fire behavior of timber - concrete composite floor system with the SBB connection system, fire tests were conducted according to ISO 834 standard. Fire results database with SBB timber - concrete connection includes a full-scale fire floor test (floor dimensions are 5.35m x 3.5m) and several fire Push Out tests based on three different timber - concrete composite beam sections. Fire Push Out tests were heavily instrumented with thermocouples in order to allow the validation of thermal models developed in this thesis.Thermal and thermomechanical coupled simulations were conducted with finite element software Abaqus©. These models demonstrate the good performances of timber-concrete composite structures subjected to fire. Heating of the elements and loss in shear resistance and stiffness of the connection system were quantified. Furthermore fire design rules are proposed for timber - concrete structures. Fire behavior analysis pointed out that thermal dilatation of concrete must be considered in fire design of timber-concrete composite structures.

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Fibre Reinforced Polymer Composites are extensively used in aircraft structures because of its high specific stiffness, high specific strength and tailorability. Though Fibre Reinforced Polymers offer many advantages, they are not free from problems. The damage of different nature, e.g., service mechanical damages, fatigue damage or environmental damage can be observed during operating conditions. Among all the damages, manufacturing or service induced, delamination related damage is the most important failure mechanisms of aircraft-composite structures and can be detrimental for safety. Delamination growth under fatigue loading may take place due to local buckling, growth from free edges and notches such as holes, growth from ply-drops and impact damaged composites containing considerable delamination. Delamination growth can also occur due to interlaminar stresses, which can arise in complex structures due to unanticipated loading. The complex nature of composite failure, involving different failure modes and their interactions, makes it necessary to characterize/identify the relevant parameters for fatigue damage resistance, accumulation and life prediction. An effort has been made in this thesis to understand the fatigue behavior of carbon fibre reinforced epoxy laminates under aircraft wing service loading conditions. The study was made on laminates with different lay-up sequences (quasi-isotropic and fibre dominated) and different geometries (plain specimen, specimen with a hole and ply-drop specimen). The fatigue behaviour of the composite was analyzed by following methods: . Ultrasonic C-Scan was used to characterize the delamination growth. . Dynamic Mechanical Analysis (DMA) was done to study the interfacial degradation due to fatigue loading. In this analysis, the interfacial strength indicator and interfacial damping were calculated. The DMA also provides the storage modulus degradation under fatigue loading. . Scanning electron microscope examination was carried out to understand the fatigue damage mechanisms. . A semi-empirical phenomenological model was also used to estimate the residual fatigue life. This research work reveals that the Carbon Fibre Reinforced Polymer laminates are in the safe limit under service loading conditions, except the specimen with a hole. The specimen with a hole showed delaminations around the hole due to stress concentration and higher interlaminar stresses at the hole edges and this delamination is found to be associated with fibre breakage and fibre pullout. The quasi-isotropic laminate is found to show poorer fatigue behaviour when compared to fibre dominated laminate and ply-drop also shows poor performance due to high stress concentration in the ply-drop region.

This study investigated the effect of sensor mass, sensor location, and delamination location of different composite structures under dynamic loading. The study pertains to research of the use of accelerometers and dynamic response as a cost-effective and reliable method of structural health monitoring in composite structures. The composite structures in this research included carbon fiber plates, carbon fiber-foam sandwich panels, and carbon-fiber honeycomb sandwich panels. The composite structures were manufactured with the use of a Tetrahedron MTP-8 heat press. All work was conducted in the Cal Poly Aerospace Structures/Composites Laboratory. Initial delaminations were placed at several locations along the specimen, including the bending mode node line locations. The free vibration of the composite structure was forced through a harmonic horizontal vibration test using an Unholtz-Dickie shake system. A sinusoidal sweep input was considered for the test. The dynamic response of the composite test specimens were measured using piezoelectric accelerometers. Measurements were taken along horizontal and vertical locations on the surfaces of the composite structures. Square inch grids were marked on the surfaces to create a meshed grid system. Accelerometer measurements were taken at the center of the grids. The VIP Sensors 1011A piezoelectric accelerometer was used to measure vibration response. The measurements were then compared to response measurements taken from a PCB Piezotronics 353B04 single access accelerometer to determine the effects of sensor mass. Deviations in bending mode natural frequency and differences in mode shape amplitude became the criteria for evaluating the effect of sensor mass, sensor location, and delamination location. Changes in damping of the time response were also studied. The experimental results were compared to numerical models created using a finite element method. The experimental results and numerical values were shown to be in good agreement. The sensor mass greatly affected the accuracy and precision of vibration response measurements in the composites structures. The smaller weight and area of the VIP accelerometer helped to minimize the decrease in accuracy and precision due to sensor mass. The effect of sensor location was found to be coupled with the effect of sensor mass and the bending mode shape. The sensor location did not affect the vibration response measurements when the sensor mass was minimized. Off-center horizontal sensor placement showed the possibility of measuring vibration torsion modes. The effect of delamination changed the bending mode shape of the composite structure, which corresponded to a change in natural frequency. The greatest effect of the delamination was seen at the bending mode node lines, where the bending mode shape was most significantly affected. The effect of delamination was also dependent on the location of the delamination and the composite structure type. The results of this study provided considerations for future research of an active structural health monitoring system of composite structures using dynamic response measurements. The considerations included sensor mass reduction, sensor placement at constraints and bond areas and the presence of damping material.

[pt] Propostas mais antigas para nominalizações sentencias se concentram nas gerundivas do inglês, analisando-as como nominalizações a partir de sentenças (Lees, 1960; Chomsky, 1970), enquanto investigações mais recentes variam em analisá-las como estruturas sentencias podadas (Frank e Kroch, 1994) ou nominalizações a partir de diferentes domínios (Abney, 1987; Alexiadou, 2001; Panagiotidis e Grohmann, 2005; Kornfilt e Whitman, 2011). Em comum, essas propostas observam a subordinação (sentencial) como gatilho para o processo de inserção de um elemento nominalizador na estrutura sintática. Enfrentam, contudo, dificuldades no tratamento da complexidade interna das estruturas resultantes, apresentando problemas de violação de c-seleção e de definição adhoc da defectividade dos traços das categorias envolvidas. O presente trabalho lança a hipótese de que as nominalizações sentenciais emergem da hibridação das categorias funcionais C e D, contestando a ideia clássica de que tais categorias constituem (tão somente) conjuntos estanques de traços. A hipótese abre caminho para uma análise das gerundivas do inglês como estruturas dominadas por uma categoria funcional híbrida, nesse caso C(interseção)D (complementizador interseção com determinante). A análise proposta pode se aplicar translinguisticamente, podendo ainda abarcar diferentes tipos de nominalização dentro de uma mesma língua. / [en] Early studies on nominalization focus on English gerunds as sentential nominalizations (Lees, 1960; Chomsky, 1970), while recent investigations vary in analysing them as pruned clauses (Frank and Kroch, 1994) or nominalizations of different syntactic domains (Abney, 1987; Alexiadou, 2001; Panagiotidis and Grohmann, 2005; Kornfilt and Whitman, 2011). In common, these proposals understand (clausal) subordination as a trigger for insertion of a nominalizer element into the syntactic structure. They face however, difficulties in dealing with the internal complexity of the resulting structures, while challenging principles of c-selection and appealing to ad-hoc definitions for the defectiveness of the involved categories. The present study raises the hypothesis that sentential nominalizations result from hybridization of the functional categories C and D, rejecting, thus, the classical idea that these functional elements are formed only by rigid, solid sets of formal features. This hypothesis paves the way for an analysis of English gerundives as structures headed by a hybrid functional category, in this case, C(intersection)D (complementizer intersection determinant). This analysis might apply crosslinguistically while explaining different types of intra-language nominalizations.

[pt] Esta dissertação tem como objetivo avaliar o comportamento estrutural de um sistema misto pré-fabricado através de um estudo teórico-experimental. O modelo estrutural é composto por dois perfis I laminados que são ligados através de conectores localizados na alma do perfil I e preenchidos por concreto armado. Foi realizado um estudo teórico baseado na análise linear elástica e formulações não lineares através do Método dos Elementos Finitos (MEF) com o uso do software ABAQUS avaliando o comportamento estrutural submetido à flexão no eixo não-múltiplo. Foi analisado o comportamento carga x deslocamento, bem como a carga última do sistema. Foi desenvolvido um programa experimental no Laboratório de Estruturas e Materiais da PUC-Rio, para avaliar o comportamento estrutural do sistema proposto, quando submetido à flexão, a fim de validar os resultados obtidos na análise numérica. Os resultados experimentais foram comparados com os resultados obtidos computacionalmente e os teóricos calculados com base na norma ABNT NBR 8800:2008. Por fim, foram avaliadas as condições econômicas para implementação do sistema e analisada a eficiência estrutural visando um método construtivo industrializado. / [en] This study aims to evaluate the structural behavior of a pre-fabricated composite system by developing a theoretical and experimental study. The structural model consists of a rolled double I section connected by its webs and filled with reinforced concrete. A theoretical study, based on linear and nonlinear static analysis considering the Finite Element Method (FEM), was done using ABAQUS software. Based on this study, an experimental programme was developed at the Structure and Materials Laboratory of PUC-Rio, to evaluate the structural behavior of the proposed system submitted to a bending test, in order to validate the numerical results obtained in the numerical analysis. The experimental results were compared to the numerical results and the design recommendations of the Brazilian standards ABNT NBR 8800:2008. Finally, the economic conditions for the implementation of the system and its structural efficiency were evaluated, aiming to industrialization of construction.

The results of a pilot series of tests, designed to investigate the influence of the presence of a composite floor slab on the performance of steel beam-to-column connections, are reported. Direct comparisons against equivalent bare steel tests show improvements in moment capacity (up to 15 times), with reinforcement anchorage being the main controlling factor. Thus joints to internal columns where the deck runs parallel to the beams and relatively small numbers of bars supplement the basic mesh reinforcement may be expected to give the best performance.

Carbon fibre reinforced plastic (CFRP) materials are of interest for the aerospace and aviation industry to master growing economic and ecological challenges. In contrast to conventional metallic materials, they offer both higher specific material properties, such as strengths, stiffnesses, and an increased energy absorption capacity in case of impact loading scenarios. Additionally, the possibility of integrating functional elements, such as actuators and sensors, predestine CFRP for the development of more lightweight structural components. In this study, a generic composite structure is instrumented with embedded piezo ceramic sensor elements. A technology for TEmSAL is presented and applied within an autoclave manufacturing process. Aspects of the designing process, manufacturing and instrumentation as well as experimental impact sensing and self-actuation results are presented and discussed.

<p>3D printing of concrete (3DPC) has been demonstrated to be a potential and viable solution for different infrastructure applications considering its multiple benefits and the continuous advances in achieving an advanced manufacturing process, using innovative materials, and using unique approaches to demonstrate high-performance characteristics. Still, some challenges remain to be addressed as this technology advances through the stages of prototyping, validation, and testing; looking to establish itself as an alternative to cast concrete for the mass production of civil infrastructure. The research presented in this dissertation is focused on the influence of the fabrication process of 3D-printed concrete on three relevant aspects for its deployment in large-scale scenarios. These aspects include the scalability of mixture development for different printing systems, the mechanical performance of reinforced 3D-printed elements, and the initial evaluation of durability properties. This research aims to contribute to the development of strategies to understand the effects of the mixture composition and the use of supplementary cementitious materials (SCMs) in the process of mixture development to enhance the printability characteristics, fresh state properties, and durability properties of these materials. Furthermore, the incorporation of novel reinforcement alternatives and controlled architectures, in addition to the study of the transport properties of 3D-printed elements can lead to advances in the use of 3D-printed concrete in structural applications.</p>