Le projet présenté dans ce mémoire a pour objectif de développer un système de récupération d’énergie des gaz d’échappement d’un véhicule à essence. Constitué de piles à combustible à oxyde solide (SOFC) en configuration monochambre, le dispositif doit convertir l’énergie chimique des gaz imbrûlés en électricité. Son fonctionnement en aval du catalyseur trois voies permettrait de compléter son action dépolluante tout en améliorant l’efficacité énergétique du véhicule. Par opposition aux piles SOFC dites conventionnelles, les piles SOFC monochambres ne nécessitent pas de scellement étanche entre les compartiments et fonctionnent sous un mélange gazeux composé d’hydrocarbures et d’oxygène. L’empilement en stack de plusieurs cellules est simplifié et plus compact, son intégration au cœur du pot d’échappement est donc plus simple. Ce concept a été précédemment étudié dans la littérature et le présent projet a pour but d’améliorer les performances délivrées en optimisant certains paramètres : la géométrie de pile et les matériaux d’électrodes et d’électrolyte. De plus, un mélange gazeux plus représentatif des conditions réelles a été défini et utilisé tout au long du projet. Une étude préliminaire sur les matériaux sous forme de poudre a permis de réaliser un premier choix parmi quatre matériaux de cathode et de définir les conditions de fonctionnement théoriques des cellules. Ensuite, les cellules complètes ont été mises en forme puis étudiées sous mélange gazeux. Une densité maximale de puissance de 25 mW.cm-2 à 550°C pour une cellule Ni-CGO/CGO/LSCF-CGO a ainsi pu être obtenue. / This study aims at developing a system able to recover energy from exhaust gases of a thermal engine. Composed of Solid Oxide Fuel Cells (SOFC) in a single chamber configuration, the device has to convert chemical energy of gases into electricity. Embedded in the exhaust line at the exit of the three-way catalyst, the stack of single chamber SOFC will complete the reduction of toxic gases emissions with an improvement of the vehicle energy efficiency.Unlike conventional SOFC, single chamber SOFC do not require any gastight sealing between compartments and work in a mixed atmosphere composed of hydrocarbon and oxygen. Stack assembly is thus simplified and more compact; insertion into the exhaust line is therefore easier. This concept has been previously studied in the literature and this work aims at enhancing performances through the optimisation of some parameters such as cell geometry and cell components materials.Moreover, a more representative gas mixture of actual compositions in the exhaust line has been defined and used all along this project. A preliminary study on the raw materials has allowed to make a first selection among four cathode materials and to define theoretical working conditions of our cells. Afterwards, cells have been elaborated and then studied in the selected gas mixture. A maximum power density of 25 mW.cm-2 has been obtained at 550°C for a Ni-CGO/CGO/LSCF-CGO cell.

Parmi les nouvelles technologies pour l’énergie inscrites dans un contexte de développement durable, les piles à combustible à membrane échangeuse de protons (PEMFC) présentent des aspects séduisants. Toutefois, pour rendre cette technologie compatible avec une application à grande échelle, elle doit répondre à des exigences strictes en termes de coût, performance, et durabilité. Alors que les plaques bipolaires métalliques sont pénalisées par leur résistance à la corrosion et celles en graphite par leurs propriétés mécaniques et leur coût (dû aux phases d’usinage des canaux), les plaques bipolaires composites apparaissent attrayantes en raison de leurs propriétés et performances et de leur coût. Cette thèse s’inscrit dans ce cadre, en proposant un matériau composite à matrice organique de type époxy et charges conductrices de graphite. L’objectif de notre étude consiste à mettre au point un matériau thermodurcissable à base d’une formulation époxyde solide (permettant de contrôler sa chimie et plus particulièrement sa réactivité) fortement chargée en graphite. Deux formulations différentes sont étudiées. La première est à base de prépolymère époxy appelé DGEBA et de dicyandiamide (DDA) comme durcisseur. L’autre formulation étudiée est constituée de DGEBA et de durcisseur : le 3,3’,4,4’-benzophénone dianhydride tétracarboxylique (BTDA). Ces deux formulations ont la particularité d’être très réactives à haute température (180-200°C) caractérisées par des temps de gel très courts (plus petit que 1min) afin d’avoir un temps de cycle de réticulation court pour une industrialisation de la fabrication. De plus, ces mêmes matrices ont montré une bonne stabilité chimique à température ambiante ainsi qu’une bonne stabilité thermique du système réticulé compatible avec la température d’utilisation des piles en fonctionnement. Concernant les réseaux composites résultant de la polymérisation DGEBA/BTDA et DGEBA/DDA, le module au plateau caoutchoutique est dominé par le taux de charge qui est très élevé (85%), celui-ci est ainsi très proche d’un réseau à l’autre et reste supérieur à 1 GPa. Nous constatons une viscosité relativement élevée pour les systèmes fortement chargés, point à prendre en compte lors du procédé de transformation. Enfin, la dernière partie des travaux réalisés concerne l’étude de mélange constitué de la matrice thermodurcissable (DGEBA/DDA/urée) modifiée par un thermoplastique (PEI). L’originalité et l’intérêt de ce travail résident dans l’incorporation de charges conductrices afin que celles-ci puissent se disperser dans la phase continue ou co-continue époxyde-amine lors de la séparation de phase pour limiter la proportion de charges et ainsi la viscosité des systèmes chargés. L’autre intérêt est d’améliorer les propriétés de résistance à la rupture du réseau époxyde TD final grâce à la présence de la phase thermoplastique séparée. / Among the new technologies for energy for sustainable development, PEM fuel cells offer seducing aspects. However, in order to make this technology fit large scale application requirements, it has to comply with stringent cost, performance, and durability criteria. While metal bipolar plates are penalized by their corrosion resistance and those based on graphite by their mechanical properties and cost (due to machining phases of the channels), the composite bipolar plates appear attractive because of their properties, performance and their cost. In such a frame, the goal of this PhD was to propose a composite material based on an epoxy matrix and graphite conductive fillers.The aim of our study was to develop a thermosetting material based on a solid epoxy formulation (to control its chemistry and in particular its reactivity) highly filled with graphite. Two different formulations were studied. The first was based on the epoxy prepolymer DGEBA and dicyandiamine (DDA) as a hardener. The other formulation studied was composed of DGEBA and curing agent: 3,3’,4,4’ benzophenone tetracarboxylic dianhydride (BTDA). Both formulations have the particularity to be very reactive at high temperature (180-200 °C) characterized by very short gel time (less than 1min) to have a short curing cycle for the industrialization of the production. In addition, these matrixes have shown good chemical stability at room temperature and good thermal stability of cross-linked system compatible with the operating temperature of the fuel cell. On composite network resulting from the polymerization DGEBA / BTDA and DGEBA / DDA, the rubbery modulus appears to be dominated by the loading rate, very high (85%), and is above 1 GPa. We see a high viscosity for highly filled systems, point to consider during the process of transformation. The final part of the work concerned the study of blend of the thermosetting matrix (DGEBA / DDA / urea) modified with a thermoplastic (PEI). The originality and interest of this work is the incorporation of conductive fillers so that they can be dispersed in the continuous or co-continuous structure during the phase separation to limit the proportion of charges and and the viscosity of filled systems. The other interest is to improve the properties of tensile strength of the thermosetting epoxy network with the presence of the thermoplastic phase.

The aim of a master's thesis is to work out a constructional technology project of Moravian regional archive in Brno. The building consists of two parts. First one, the administrative part, is formed by steel main structure and the second one, the depot, which will be used for storage of archivals is formed by reinforced concrete monolithic skeleton. The whole construction is based on bored reinforced concrete piles and located in the undeveloped area at sloping terrain. This thesis will include a progress of realization this object, design machine group, technological rule of the selected phase, financial and timetable plan of realization.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18558号 / 工博第3919号 / 新制||工||1602(附属図書館) / 31458 / 京都大学大学院工学研究科社会基盤工学専攻 / (主査)教授 平石 哲也, 教授 間瀬 肇, 准教授 馬場 康之 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

The main topic of this thesis concerns the behavior of concrete pile cap supported by four piles with two varying positions of longitudinal reinforcements. The positions include top of piles and bottom of the pile cap. For this purpose, non-linear finite element models of a pile cap are created using software ATENA 3D. The goal was to observe which position of reinforcement yields the higher bearing capacity and to observe the failure modes in the models. To achieve the above goals, a short review of theoretical background concerning shear phenomena is performed. This, in order to enhance the knowledge regarding shear stresses, shear transfer mechanism, factors affecting shear capacity, modes of shear failure and relate them to the behavior of pile cap. Furthermore, the calculation of shear resistance capacity based on Eurocode 2 using strut and tie method and sectional approach is presented. The numerical analysis started by creating four pile cap models in ATENA 3D. The difference between the models being the position and ratio of longitudinal reinforcement. The purpose behind two reinforcement ratios were to observe the behavior of pile cap model in two cases: a) when failure occurs prior to yielding of reinforcement; b) when failure occurs while reinforcement is yielding. The models are then analyzed using software ATENA Studio. The results revealed that placing the reinforcement on top of piles in case (a) increased the capacity of the model by 23.5 % and in case (b) increased the capacity by 18.5 %. This because the tensile stresses were found to be concentrated on top of piles rather than the bottom of the pile cap. The final failure mode in the model with top reinforcement position was crushing of the inclined compressive strut at the node beneath the column and in the model with bottom reinforcement position, the splitting of the compressive strut due to tensile stresses developed perpendicular to the inclined strut. The potential advantage of placing the reinforcement at the bottom were a better crack control in serviceability limit state and a slightly less fragile failure mode compared to the top position of reinforcement. A parametric study was performed in the model as well to observe the effects of various parameters on the results obtained. It was found that fracture energy had the most significant effect on the results obtained. Finally, a comparison between the results of numerical analysis and analytical design approaches based on strut and tie method and sectional approach was performed. The comparison reveals that the design values obtained based on strut and tie method for the model were very conservative. In particular, the equation for the strength of inclined compressive strut based on Eurocode 2 was very general. / Det huvudsakliga ämnet för den här avhandlingen handlar om beteendet hos pålfundament som stöds av fyra pålar med två olika positioner av längsgående armering. Positionerna inkluderar toppen av pålarna och botten av slagdynan. För detta ändamål skapas icke-linjära finita elementmodeller av en slagdyna med mjukvaran ATENA 3D. Målet var att observera vilket armeringsläge som ger den högre bärkapaciteten och att identifiera brottmekanismen i modellerna. För att uppnå ovanstående mål utförs en kort genomgång av teoretisk bakgrund rörande skjuvningsfenomen. Detta för att förbättra kunskapen om skjuvspänningar, skjuvöverföringsmekanism, faktorer som påverkar skjuvkapacitet, skjuvbrott och relaterar dem till beteendet hos slagdynan. Beräkningen av skjuvmotståndet baserad på Eurocode2 med hjälp av Srut and tie-metod och sektionsmetod. Den numeriska analysen började med att skapa fyra pålfundament i ATENA 3D. Skillnaden mellan modellerna är positionen och förhållandet mellan längsgående armering. Syftet bakom två armeringsförhållanden var att observera beteendet hos slagdynan i två fall: a) när brott inträffar innan armering plasticeras; b) när brott inträffar medan armeringen plasticeras. Modellerna analyseras sedan med hjälp av programvaran ATENA Studio. Resultaten visade att placering av armeringen ovanpå pålarna i fall a) ökade modellens kapacitet med 23,5% och i fall (b) ökade kapaciteten med 18,5%. Detta på grund av att dragspänningarna visade sig vara koncentrerade på toppen av pålarna snarare än på botten av slagdynan. Det slutliga brottet i modellen med topparmeringsposition var krossning av det lutande tryckstaget vid noden under pelaren. I modellen med bottenarmeringsposition delades kompressionsstaget på grund av dragspänningar vinkelrätt mot det lutande staget. The potential advantage of placing the reinforcement at the bottom were a better crack control and slightly less fragile failure mode compared to the top position of reinforcement. En parametrisk studie genomfördes också i modellen för att observera effekterna av olika parametrar på de erhållna resultaten. Det visade sig att brottenergi hade den mest signifikanta effekten på de erhållna resultaten. Slutligen genomfördes en jämförelse mellan resultaten från numerisk analys och analytiska designmetoder baserade på strut and tie-metoden och sektionsmetoden. Jämförelsen avslöjar att de designvärden som erhölls baserat på strut and tie-metoden för modellen var mycket konservativa. I synnerhet var ekvationen för kapaciteten hos det lutande tryckstag baserad på Eurocode 2 mycket generell.

Västlänken i Göteborg är ett tunnelprojekt för järnväg som skall byggas under centrala Göteborg. Tunneln byggs genom både berg och lera, projektet kommer att använda sig av ett flertal tekniker och konstruktionslösningar. Västlänken är ett av de första stora infrastrukturprojekt i Sverige där slitsmurar används som permanenta konstruktioner. På uppdrag av Trafikverket har två olika typer av stödmurskonstruktioner undersökts med avseende på deras klimatpåverkan. Konstruktionslösningarna är en temporär spont med tillhörande tunnelvägg och en slitsmur. Slitsmuren används både som en temporär konstruktion under byggskedet och en del i den permanenta tunnelväggen. Slitsmurar har först nyligen blivit godkända att användas som delar av permanenta konstruktioner av Trafikverket. Av denna anledning finns det inte mycket information om konstruktionens klimatpåverkan. Syftet med rapporten är att undersöka klimatpåverkan från de två olika konstruktionslösningarna. Jämförelsen har gjorts med hjälp av livscykelanalyser för att få den mest övergripande analysen. En livscykelanalys (LCA) är ett verktyg för att synliggöra en produkts totala miljöpåverkan under dess livstid. Detta åstadkoms genom att alla de olika delprocesser som krävs för att skapa produkten inventeras och analyseras. LCA har utförts med datorprogrammet SimaPro och databasen Ecoinvent. I SimaPro har båda konstruktionslösningarna modellerats och deras miljöpåverkan sedan beräknats med ReCiPe 2016. Indata till LCA har samlats in från ritningar och diskussioner med experter på området. Resultatet från livscykelanalysen visar att slitsmurarna i detta projekt har större klimatpåverkan än konstruktionslösningen med spont och en platsgjuten betongmur. För slitsmuren står armering samt betong för den största delen av klimatpåverkan och för sponten är det den stora mängden stål som krävs vid de kraftiga dimensionerna. Då en del av konstruktionerna inom projektet ej var färdigprojekterad när denna rapport författades rekommenderas ytterligare studier på ämnet för att validera resultaten / The West Link Project is as tunnel project for the railroad that will be constructed below central Gothenburg. The project is built through clay and solid rock thus making use of several techniques and structural solutions. The West Link Project (Västlänken) is the first major infrastructure project in Sweden where diaphragm walls are used as a part of the permanent structure. Two different structures have been examined on behalf of the Swedish Transport Administration, with regards to their climatic impact. The two structures examined are a temporary sheet pile with a cast-in-place concrete wall that is used as a part of the tunnel wall, and a diaphragm wall. The diaphragm wall is used as an earth retaining wall during the construction stage and as a part of the permanent tunnel wall. Diaphragm walls have just recently been approved as parts of permanent structures by the Swedish Transport Administration. Due to this there isn’t a lot of information available on their climatic impact. The purpose of this paper is to examine the climatic impact of these two different structures. The comparison has been performed by the use of a lifecycle analysis to get the most comprehensive analysis. A lifecycle analysis (LCA) is a tool that helps to get a perspective on a product’s total environmental impact over the course of its lifetime. This is accomplished by doing an inventory of all the different processes involved in its production. For the LCA the computer program SimaPro, and the database Ecoinvent were used. In SimaPro both of the structure have been modelled and their environmental impact has been calculated with ReCiPe 2016.Input for the LCA have been gathered from drawings and communication with experts. The result of the LCA shows that in this project the diaphragm walls have a higher climatic impact than the sheet pile and concrete wall. With regards to the diaphragm wall the majority of its climatic impact is from the large amounts of reinforcement and concrete used. For the sheet pile the steel used to manufacture sheets of the dimensions used in the project is the largest contributing factor. Due to the fact that some of the structures in the project are still being at the design stage at the time of writing further studies are recommended to validate the results.

This thesis designs attractive living for students and affect positively surrounding areas. Integrate suitable functions to improve the quality of quater.

Skewed bridges have exhibited poorer performance during lateral earthquake loading when compared to non-skewed bridges (Apirakvorapinit et al. 2012; Elnashai et al. 2010). Results from small-scale laboratory tests by Rollins and Jessee (2012) and numerical modeling by Shamsabadi et al. (2006) suggest that skewed bridge abutments may provide only 35% of the non-skewed peak passive resistance when a bridge is skewed 45°. This reduction in peak passive force is of particular importance as 40% of the 600,000 bridges in the United States are skewed (Nichols 2012). Passive force-deflection results based on large-scale testing for this study largely confirm the significant reduction in peak passive resistance for abutments with longitudinal reinforced concrete wingwalls. Large-scale lateral load tests were performed on a non-skewed and 45° skewed abutment with densely compacted sand backfill. The 45° skewed abutment experienced a 54% reduction in peak passive resistance compared to the non-skewed abutment. The peak passive force for the 45° skewed abutment was estimated to occur at 5.0% of the backwall height compared to 2.2% of the backwall height for the non-skewed abutment. The 45° skewed abutment displayed evidence of rotation, primarily pushing the obtuse side of the abutment into the backfill, significantly more than the non-skewed abutment as it was loaded into the backfill. The structural and geotechnical response of the wingwalls was also monitored during large-scale testing. The wingwall on the obtuse side of the 45° skewed abutment experienced nearly 6 times the amount of horizontal soil pressure and 7 times the amount of bending moment compared to the non-skewed abutment. Pressure and bending moment distributions are provided along the height of the wingwall and indicate that the maximum moment occurs approximately 20 in (50.8 cm) below the top of the wingwall. A comparison of passive force per unit width suggests that MSE wall abutments provide 60% more passive resistance per unit width compared to reinforced concrete wingwall and unconfined abutment geometries at zero skew. These findings suggest that changes should be made to current codes and practices to properly account for skew angle in bridge design.

This thesis focuses on the field performance of IsoTruss®-reinforced concrete beam columns for use in driven piles. Experimental investigation included one instrumented carbon/epoxy IsoTruss®-reinforced concrete pile (IRC pile) and one instrumented steel-reinforced concrete pile (SRC pile) which were driven into a clay profile at a test site. These two piles, each 30 ft (9 m) in length and 14 in (36 cm) in diameter, were quasi-statically loaded laterally until failure. Behavior was predicted using three different methods: 1) a commercial finite difference-based computer program called Lpile; 2) a Winkler foundation model; and, 3) a simple analysis based on fundamental mechanics of materials principles. Both Lpile and Winkler foundation model predictions concluded that the IRC pile should hold approximately twice the load of the SRC pile. Applying mechanics of materials principles found the predicted stiffness of the piles to be consistent with the laboratory results. Due to unresolveable errors, experimental field test data for the SRC pile is inconclusive. However, analysis predictions in conjunction with field test data for the IRC pile show that the IRC pile should perform similar to predictions and laboratory test results. Therefore, IsoTruss® grid-structures are a suitable alternative to steel as reinforcement in driven piles.

Pile foundations near the crest of a slope are often required to resist lateral loads. This is particularly important for piles at the abutments of bridges. However, limited full-scale test data are available to indicate how the lateral resistance of a pile would be affected when it is located near the crest of a slope. To investigate the effect of a slope on lateral pile resistance, three full scale lateral load tests were conducted on an instrumented steel pipe pile. For the first test, the pile was laterally loaded in horizontal ground. For the second test the pile was at the crest of a 30 degree slope and in the third test the pile was placed three diameters behind the crest of the 30 degree slope. The soil around the pile consisted of clean sand compacted to about 95% of the modified Proctor maximum unit weight for all three tests. Laboratory and in-situ direct shear tests indicated that the friction angle of the sand was approximately 39 degrees. The pile was instrumented with strain gages at approximately 1.5 ft intervals along its length so that the bending moment versus depth profile could be determined. Pile head load, deflection, and rotation were also measured. Based on the results, the presence of the slope decreased the ultimate lateral resistance of the pile-soil system by approximately 25% and 10% for tests two and three, respectively. The presence of the slope also resulted in an increase in the maximum bending moment of approximately 40% and 30% for tests two and three, respectively. Analyses using LPILE matched the lateral resistance for the pile in horizontal ground, but significantly overestimated the decrease in resistance due to the sloping ground. A mathematical model was developed to predict the ultimate strength of a pile located some distance from the crest of a cohesionless sloping profile. Parametric test results using the model were within 2.6 % of the measured results of tests two and three.