No / In steel¿concrete composite beams, the longitudinal shear force is transferred across the steel flange/concrete slab interface by the mechanical action of the shear connectors. The ability of the shear connectors to transfer these longitudinal shear forces depends on their strength, and also on the resistance of the concrete slab against longitudinal cracking induced by the high concentration of shear force. Most of the research in composite construction has concentrated on the more traditional reinforced concrete and metal deck construction, and little information is given on shear capacity of the headed studs in precast hollowcore slabs. In this paper, a standard push test procedure for use with composite beams with precast hollowcore slabs is proposed. Seven exploratory push tests were carried out on headed studs in solid RC slabs to validate the testing procedures, and the results showed that the new test is compatible with the results specified in the codes of practice for solid RC slabs. Once a standard procedure is established, 72 full-scale push tests on headed studs in hollowcore slabs were performed to determine the capacities of the headed stud connectors in precast hollowcore slabs and the results of the experimental study are analysed and findings on the effect of all the parameters on connectors¿ strength and ductility are presented. Newly proposed design equations for calculating the shear connectors¿ capacity for this form of composite construction are also be given.

Yes / Herein, we report a catalyst-free ‘click’ reaction: metal-free [2 + 2] cycloaddition–retro-electrocyclisation (CA–RE) of arylynamines with the sluggish acceptor tetracyanoquinodimethane (TCNQ) to provide orthogonal electron-push–pull light-harvesting small molecules: N-heterocyclic dicyanoquinodimethane-substituted methylene malononitriles. Ynamines are reactive alkynes and tend to induce over-reactions with the CA–RE adducts. The reactivity of arylynamines was balanced properly by ensuring the electrondensity of the nitrogen atom was delocalised more over the aromatic rings than the triple bond. / This work was supported by Guangxi Natural Science Foundation (2020JJA120032). / Research Development Fund Publication Prize Award winner, April 2022.

År 2004 blev det känt att delar av Kiruna skulle komma att flyttas för att möjliggöra gruvbrytning i gruvan Kirunavaara. Sedan dess har den byggda miljön i orten påverkats på flera sätt, och därmed även de med anknytning till Kiruna. Denna kandidatuppsats undersöker inställningen till förändringarna i den byggda miljön hos unga vuxna som vuxit upp i Kiruna, men som senare flyttat till Uppsala för studier, samt hur deras syn på att återvända till Kiruna eventuellt kan ha påverkats av stadsflytten. Metoden som använts för att besvara studiens syfte bestod av sex semistrukturerade intervjuer med före detta Kirunabor som flyttat till Uppsala för studier, och bor kvar i Uppsala idag. Resultatet visade att förändringarna i den byggda miljön inte i huvudsak styr hur respondenterna planerar sin eventuella återflytt till Kiruna. Det sompåverkar respondenternas inställning negativt var snarare otillgänglighet till samhällstjänster och oro över framtiden. Å andra sidan visar respondenterna att Kirunas närhet till naturen och familjeliv lockar till att återvända.

yes / In this work, the interfacial bond performance of recycled aggregate concrete filled stainless steel tube (RAC-FSST) members was investigated through the repeated push-out tests. Three coarse recycled aggregate (CRA) replacements (0, 50% and 100%) and two cross-sectional dimensions were considered in the experimental program. The failure pattern, bond stress-slip response and strain development of stainless steel tube were obtained, and the bond mechanisms under different loading stages were analyzed. Test results showed that the ultimate bond stress increases with the increasing CRA content and decreasing cross-sectional dimensions. Compared with CFST members having carbon steel, RAC-FSST members present lower bond stress. The macro-interlocking effect is obvious in the later loading stage, resulting in a significant increase in the post-peak bond slip curves. Finally, the ultimate bond strength and idealized bond stress-slip models for the RAC-FSST members were suggested on the basis of the test results.

This thesis investigates the impact of interface surface treatment methods for use in the Virginia Inverted T-Beam bridge system. The specific system consists of precast beams with thin bottom flanges placed next to one another, with a cast-in-place slab on top. Previous research has shown that the strength of this system after cyclic loading is highly dependent upon the shear strength of the interface between the precast and cast-in-place sections, especially for the adhesion-based connection configuration. The approval of this bridge system for use in bridges with high daily traffic volumes hinges on the verification of its strength and durability for a 50-year lifespan. The shear strength of ten different surface textures was tested using push-off tests to determine which interface roughening methods would prove adequate for use in the bridge system. The strength was found to depend on both the amplitude and the geometry of the undulations on the beam-to-slab interface. Using this information, a texture was selected for a new trial of the adhesion-based connection configuration, and a test specimen was constructed. After completing cyclic loading to simulate the design life of the bridge, it was found that the system achieved a strength similar to previous monotonically loaded specimens. It was concluded that the bridge is safe for use in high daily traffic areas provided that a surface roughening with adequate shear strength is used. / Master of Science / The Virginia Inverted T-Beam bridge system was initially designed to be more durable and economical than other types of bridges. The bridge is constructed by arranging prefabricated beams side-by-side across the span before placing fresh concrete overtop. In the most economical version of the system, the only connection between the beams is the newly placed concrete. For the beams and topping to act together, the bond between them must be strong. Roughening the surface of the prefabricated beams increases the strength of the bond, although different roughening patterns achieve different levels of strength. Past tests of the bridge system have utilized inadequate roughing patterns which lead to low bridge failure loads after many loading cycles. This low-cost configuration is currently only approved for use in low daily traffic areas. The goal of this research was to determine a roughening pattern that would result in a high bridge failure load which would allow the low-cost configuration to be approved for high daily traffic areas. Several roughening patterns were investigated and the patterns producing the highest shear strengths were determined. The best pattern was chosen to be used for the bridge configuration and a sub-section of the bridge was constructed. This specimen was subjected to a loading protocol that simulated the traffic that an actual bridge would be subjected to over its life span. The failure load was then measured and found to be high enough to warrant the use of the specific system in high daily traffic areas.

[EN] This thesis proposes a method for assessing the seismic vulnerability of the residential building in Valencia, understood according to the definition of Sandi (1983), and prediction of damage to buildings in terms of seismic intensity. With this aim, we have studied different methods of analysis of vulnerability and damage to the building, ranging from the simplest based on visual observation to others involving the use of computer applications for estimating capacity and demand curves models using push-over. Given the complexity of the models of the behavior of buildings under earthquake and scattering observations recorded earthquakes in history, none of these methods is able to provide a satisfactory predicting expected damages under any circumstances. Therefore, we maintain a reliable estimate of the seismic vulnerability of buildings should be based on the correlation results or combination of different methods. For this purpose, first, we have presented the state of the art on evaluation methods available. Then we characterized the Valencian housing stock and identified their most representative building types. From this description, we estimated the expected damage in these buildings according to their situation and the intensity of the earthquake, by applying the general methods of assessment and, in the case of a particular building representative, the application of models push-over. Finally, we compared the results obtained and we discussed possible strategies correlation and interpretation of different methods. / [ES] Esta tesis propone un método de evaluación de la vulnerabilidad sísmica de la edificación residencial valenciana, entendida de acuerdo con la definición de Sandi (1983), y de predicción de los daños en las construcciones en función de la intensidad sísmica. Con este objetivo, hemos estudiado diferentes métodos de análisis de vulnerabilidad y daños en la edificación, abarcando desde los más sencillos basados en la observación visual hasta otras que impliquen la utilización de aplicaciones informáticas para la estimación de las curvas de capacidad-demanda mediante modelos push-over. Teniendo en cuenta la complejidad de los modelos de aproximación al comportamiento de los edificios sometidos a sismo y la dispersión en las observaciones registradas en terremotos históricos, ninguno de estos métodos es capaz de ofrecer una predicción satisfactoria de los daños esperados en cualquier circunstancia. Por ello, sostenemos que una estimación fiable de la vulnerabilidad sísmica de los edificios debe basarse en la correlación o combinación de resultados de diferentes métodos. Con este objetivo, en primer lugar, hemos presentado el estado del arte sobre los métodos de evaluación disponibles. A continuación, hemos caracterizado el parque inmobiliario valenciano e identificado sus tipos edificatorios más representativos. A partir de esta caracterización, hemos estimado el daño esperado en estos edificios en función de su situación y de la intensidad del sismo, mediante la aplicación de los métodos generales de evaluación y, en el caso de un edificio particular y representativo, la aplicación de modelos push-over. Por último, hemos comparado los resultados obtenidos y hemos discutido posibles estrategias de correlación e interpretación de los diferentes métodos. / [CA] Aquesta tesi proposa un mètode d'avaluació de la vulnerabilitat sísmica de l'edificació residencial valenciana, entesa d'acord amb la definició de Sandi (1983), i de predicció dels danys en les construccions en funció de la intensitat sísmica. Amb aquest objectiu, hem estudiat diferents mètodes d'anàlisi de vulnerabilitat i danys en l'edificació, abastant des dels més senzills basats en l'observació visual fins a d'altres que impliquen la utilització d'aplicacions informàtiques per a l'estimació de les corbes de capacitat-demanda mitjançant models push-over. Tenint en compte la complexitat dels models d'aproximació al comportament dels edificis sotmesos a sisme i la dispersió en les observacions registrades en terratrèmols històrics, cap d'aquests mètodes és capaç d'oferir una predicció satisfactòria dels danys esperats en qualsevol circumstància. Per això, sostenim que una estimació fiable de la vulnerabilitat sísmica dels edificis ha de basar-se en la correlació o combinació de resultats de diferents mètodes. Amb aquest objectiu, en primer lloc, hem presentat l'estat de l'art sobre els mètodes d'avaluació disponibles. A continuació, hem caracteritzat el parc immobiliari valencià i identificat els seus tipus edificatoris més representatius. A partir d'aquesta caracterització, hem estimat el dany esperat en aquests edificis en funció de la seua situació i de la intensitat del sisme, mitjançant l'aplicació dels mètodes generals d'avaluació i, en el cas d'un edifici particular i representatiu, l'aplicació de models push-over. Finalment, hem comparat els resultats obtinguts i hem discutit possibles estratègies de correlació i interpretació dels diferents mètodes. / Iborra Posadas, J. (2016). ESTIMACIÓ DE LA VULNERABILITAT SÍSMICA D'UNA ZONA RESIDENCIAL I PREDICCIÓ DEL SEU DANY ESPERAT EN FUNCIÓ DE LA INTENSITAT SÍSMICA [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/62592

京都大学 / 新制・課程博士 / 博士(理学) / 甲第25097号 / 理博第5004号 / 新制||理||1714(附属図書館) / 京都大学大学院理学研究科数学・数理解析専攻 / (主査)教授 望月 新一, 教授 大木谷 耕司, 准教授 星 裕一郎 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM

Le travail rapporté dans ce mémoire de thèse concerne la synthèse et la caractérisation de nouveaux semi-conducteurs organiques basés sur un coeur bithiophène. Ce travail s'inscrit dans le prolongement de précédents travaux réalisés au laboratoire portant sur des dérivés du type distyryl-oligothiophènes. Au cours de ce travail, plusieurs voies de synthèse ont été développées afin de fonctionnaliser un coeur bithiophène, rigide ou non, avec différents groupements fonctionnels, principalement pour trois types d'applications : (i) la réalisation de transistors à base de couche mince organique (OFETs), (ii) l'élaboration de cellules solaires à partir de composés push-pull et (iii) le développement de capteurs. Le premier chapitre est consacré à la fonctionnalisation du benzo-[2,1-b:3,4-b']dithiophène-4,5-dione soit par des groupements mésogéniques soit par des motifs aminostyryles. L'objectif est la possibilité de préparer des OFETs par la voie liquide et de tirer profit des propriétés cristal liquide pour améliorer les performances électriques. Les propriétés cristal liquides ont été décrites, et les transistors réalisés. Malheureusement aucune mobilité de porteur de charge n'a pu être enregistrée. Dans un deuxième temps, des modifications structurales ont été apportées sur certaine des structures synthétisées afin d'améliorer les propriétés recherchées. Toutefois, au moment de la rédaction de ce manuscrit, les OFETs n'étaient pas réalisés. Dans le deuxième chapitre, de nouvelles molécules push-pull de type cruciformes ont été synthétisées dans le but d'évaluer leurs performances en tant que composés organiques actifs dans des dispositifs photovoltaïques. / The work reported herein concerns the synthesis and the characterization of new organic semiconductors built around the bithiophene core. It was relied on an extended work carried out previously in our laboratory on distyryloligothiophene derivatives. The main part of this work was dedicated to develop new functionalized organic semi-conductors with the aim to improve their properties for optoelectronic applications, mainly for: i) the realization of transistors with organic thin layer (OFETs), ii) the elaboration of solar cells from push-pull derivatives and iii) the development of sensors. The first chapter is devoted to the functionalization of the benzo-[2,1-b:3,4-b ']bithiophene-4,5-dione core either by mesogenic or aminostyryl groups with the purpose to improve, using liquid crystal properties, the microscopic ordering and the electrical performances of the synthetized organic semiconductors as well as their solution processability. Besides the liquid crystal properties characterization showing interesting behavior, the OFET devices have been made from those semiconductors but unfortunately have led to, as unexpected, poor charge transport properties. Some structural modifications have been done in order to optimize the charge transport characteristics nevertheless their electrical characterization still under progress up to now. In a second part, some push-pull derivatives, having a cruciform-like structure, have been synthetized and characterized in order to use them as an active organic layer in photovoltaic devices. Their optoelectronic properties have been evaluated and reported.

This thesis deals with the distributed and stochastic algorithms including testing their convergence in networks. The theoretical part briefly describes above mentioned algorithms, including their division, problems, advantages and disadvantages. Furthermore, two distributed algorithms and two stochastic algorithms are chosen. The practical part is done by comparing the speed of convergence on various network topologies in Matlab.

Ce travail porte sur l'étude des comportements en flexion à court et long termes des poutres hybrides collées constituées d'un profilé pultrudé GFRP et d'une dalle en béton, assemblés par un joint de colle époxy. L'utilisation du collage dans des structures réelles se heurte encore à la réticence des concepteurs en raison du manque de garanties sur la durabilité à long terme et de l'absence d'outils de modélisation donnant la durée de vie en service des assemblages collés. La présente étude constitue donc un jalon dans cette démarche de compréhension du comportement à long terme de ces structures collées. Elle s'appuie sur analyse multi-échelles qui permet d'aborder le problème à l'échelle locale de l'interface (essai pushout) et à l'échelle globale de l'élément de structure (essai de flexion sur des poutres). Des essais de vieillissement accéléré ont tout d'abord été conduits pour étudier les effets de l'humidité et de la température sur l'adhésif seul et sur l'assemblage structural et il en ressort que l'eau, et notamment une immersion prolongée, s'avère particulièrement néfaste à la résistance au cisaillement des éprouvettes et modifie leur mode de ruine. La réponse instantanée de l'assemblage pultrudé-béton a ensuite été plus amplement étudiée. Grâce à une étude paramétrique expérimentale, une géométrie et une méthode de fabrication des éprouvettes ont été définies pour assurer la reproductibilité des résultats et limiter leur dispersion. De plus, un modèle numérique 3D a été développé dans le code d'éléments finis Cast3m et montre une distribution de contraintes, notamment de cisaillement, non uniforme le long de la surface de collage avec une concentration aux extrémités du joint. Une analyse paramétrique numérique a permis d'identifier les dimensions des dallettes et du joint de colle comme des paramètres influents sur la résistance des éprouvettes. Enfin, le comportement en fluage d'une poutre hybride est étudié. Sous l'effet d'un vieillissement naturel, seul, le joint d'adhésif ne s'avère pas impacté. Des essais de fluage en flexion 3-points ont été effectués pour étudier les réponses à long terme du profilé seul et de la poutre hybride. Ils montrent une augmentation considérable du déplacement des poutres en raison du fluage et du retrait du béton et du fluage du profilé. Des modèles 3D en variables locales, dans le cadre de la viscoélasticité linéaire, sont développés dans Cast3m et permettent de fidèlement restituer l'évolution des déplacements et des états de déformation au cours du temps pour les différentes poutres testée / This dissertation focuses on the short- and long-term responses of bonded hybrid beams consisting of a GFRP-pultruded profile bonded by an epoxy adhesive joint to a reinforced concrete-slab. The problems related to the durability and the long-term response of these structures still represent an open issue. The present study is meant to increase the knowledge and understanding of these hybrid structures in this context. Firstly, different accelerated ageing tests were carried out to evaluate the effects of some environmental agents such as water, moisture and freeze thaw cycles in the behaviour of GFRP/concrete bonded assemblies. Mechanical characterizations were carried out on control and exposed of both materials and push-out specimens to quantify the degradation and damage of the mechanical resistance of each material and of the adhesive bond properties. The water effect on the adhesion of the joints was found to be significant, especially at longer immersion times. The second part was directed at characterizing the push-out test. An experimental parametric study was performed to elaborate a methodology of fabrication of the push-out specimens that can reduce the dispersion of results and give an accurate prediction of the shear strength on a limited set of specimens. Also, a 3D finite-element model was developed using the finite-element code Cast3m. This model showed that the stress components, especially peel and shear stresses, are not constants across the bonding area and peaking near the free edges (stress concentrations). A numerical parametric study allowed to conclude that the most effective geometrical parameters influencing bond between GFRP and concrete were the bonded length and the dimensions of the concrete substrate. Last part deals with experimental and numerical investigations carried out to study the short- and long-term flexural behaviour of full-scale hybrid beams. All experiments showed considerable increase in beam deflection over time due to concrete creep and shrinkage and GFRP creep. Finally, 3D-finite-element models, realized with Cast3m, are developed based on the incremental formulation of the linear-viscoelasticity theory. The proposed models allow evaluation of the long-term deflection of the pultruded and hybrid beams. Using the proposed model, evolution with time of stresses, strains and displacements in different location of the hybrid beam are obtained