Usualmente, em situações práticas de projeto de lajes mistas, procura-se uniformizar ao máximo a espessura das fôrmas de aço, normalmente por razões econômicas (produção em larga escala). Entretanto, em alguns casos, há a necessidade de se especificarem algumas fôrmas com maior espessura, solução essa pouco competitiva no mercado brasileiro. Uma alternativa economicamente interessante em relação ao aumento de espessura é a inserção de armadura adicional, mantendo-se assim a espessura padrão (em geral 0,80 mm) e obtendo-se aumento da área de aço por meio de vergalhões. No entanto, por se tratar de uma solução inusual, o comportamento estrutural das lajes mistas com armadura adicional e seus critérios e diretrizes de dimensionamento não são previstos em normas e manuais técnicos: a ABNT NBR 8800 (2008, p. 226) e o Eurocode 4 (2004, p. 104) mencionam que, caso haja armadura para resistir ao momento fletor positivo, a formulação apresentada deverá ser adequadamente ajustada, mas não apresentam os respectivos critérios e equacionamentos. O ANSI/ASCE 3-91 (1992), o CSSBI S2-2008 (2008) e o ANSI/SDI C-2011 (2011) não mencionam a possibilidade de armadura adicional. Diante desse cenário, investigou-se o comportamento estrutural de lajes mistas com vergalhões e, por meio de uma extensão matemática das formulações já existentes para o caso sem armadura, foram propostos critérios de dimensionamento para os estados-limites últimos (momento fletor e cisalhamento longitudinal) e de serviço (deslocamento vertical). Foram realizados ensaios de flexão em doze protótipos de lajes mistas de dimensões usuais, sendo oito sem barras adicionais e quatro com, variando-se as dimensões (altura e vão, conforme Eurocode 4 (2004)) e com quatro taxas de armadura. A partir desses resultados, pôde-se analisar o comportamento estrutural dos protótipos com armadura adicional, os quais apresentaram ductilidade e capacidade consideravelmente maiores que as correspondentes lajes sem as barras. Por fim, também foram validadas as formulações referentes ao cisalhamento longitudinal (extensões do Método m-k e do Método da Interação Parcial) e ao deslocamento vertical, para os casos mais usuais. / Usually, on the design of composite slabs with profiled steel decking, it is tended to standardize as much as possible the thickness of the steel decking, generally because of economic reasons (large-scale production). Nevertheless, in a few cases it must be necessary to specify thicker steel decking, which is not a competitive solution in the Brazilian market. An economic alternative regarding the increase of thickness is the insertion of additional bottom reinforcement, thus, keeping the standard thickness (in general 0.80 mm) and obtaining the steel area increment through rebars. Notwithstanding, since that is an unusual solution, the structural behavior of composite slabs with additional reinforcement, their criteria and design guidelines are not provided in standards and technical manuals: ABNT NBR 8800 (2008) and Eurocode 4 (2004) state that, if there are additional bars to resist positive bending moment, the formulation should be adapted, however they do not present the respective criteria and equating. CSSBI S2-2008 (2008), ANSI/ASCE 3-91 (1992) and ANSI/SDI C-2011 (2011) do not mention the possibility of using additional reinforcement. In this scenario, the structural behavior of composite slabs with rebars was investigated and, through a mathematic extension of the formulation already used to the unreinforced situation, design criteria were proposed for the ultimate (flexure and longitudinal shear) and serviceability (deflection) limit states. In addition, flexure tests were carried out in twelve composite slabs with usual dimensions, eight of those without additional bars and four with, following the recommendations by Eurocode 4 (2004) about the variation of the dimensions (height and span), with the latter having four reinforcement rates. With the results of those tests, the structural behavior of the reinforced prototypes was analysed, which have showed considerably higher ductility and resistance when compared to those with the unreinforced ones. Finally, the formulations for the usual cases related to longitudinal shear (extensions of the m-k Method and the Partial Interaction Method) and deflection were validated.

Este trabalho tem por objetivo investigar a contribuição da armadura para a capacidade resistente de vigas mistas parcialmente revestidas, bem como sua eficiência para promover o comportamento conjunto aço-concreto, imprescindível para a obtenção de vigas mistas. O estudo engloba uma investigação experimental com ensaios de vigas sob flexão em quatro pontos e uma simulação numérica utilizando o pacote computacional DIANA®, visando obter dados do comportamento de vigas mistas parcialmente revestidas com armadura longitudinal. Foram ensaiados quatro modelos de viga mista parcialmente revestida e duas variáveis foram analisadas: taxa de armadura longitudinal no concreto e posição dos conectores tipo pino com cabeça. Os resultados experimentais mostraram a eficiência do conjunto armadura-conector para o aumento da capacidade resistente à flexão e para a promoção da interação aço-concreto. A simulação numérica teve concordância satisfatória com os resultados experimentais obtidos. / This study aims to investigate the contribution of the steel bars to the flexure capacity and to promote the composite behavior in partially encased composite beams. The study includes an experimental investigation of partially encased beams under bending in four points and a numerical simulation using the computer package DIANA® to collect data from the behavior of partially encased composite beams with longitudinal reinforcement. Four models of partially encased composite beams were tested and two variables were analyzed: rate of longitudinal reinforcement in concrete and position of stud bolts. The experimental results showed the efficiency of the junction between reinforcing bars and stud bolt to the increase the bending capacity of the partially encased beam and to obtain the steel-concrete interaction. The numerical simulation has good agreement with the experimental results.

Les structures composites sont souvent exposées à des ambiances dynamiques plus oumoins sévères. Ces vibrations peuvent développer différentes formes d’endommagement(fracture des fibres, délamination, fissuration de la matrice. . . ). Les défauts locaux sepropagent et affectent les propriétés mécaniques de la structure modifiant ainsi soncomportement dynamique global. Ces changements peuvent induire une dégradationrapide de la structure et une réduction de sa durée de vie. La thèse a pour objectif lamise en oeuvre de modèles de comportement pour le dimensionnement de structurescomplexes intégrant des sous-structures composites susceptibles d’être endommagées.La méthode des éléments finis est utilisée pour modéliser le comportement vibratoirelinéaire et non-linéaire de ces structures et l’endommagement est introduit via un modèlebilatéral, dans un premier temps. Durant le processus de résolution, une des difficultésrencontrées est le coût de calcul très élevé. Ainsi, un méta-modèle a été développé basésur les réseaux de neurones artificiels couplé avec la méthode de condensation par sousstructurationde Craig-Bampton. Les réseaux de neurones artificiels permettent d’estimer,à moindre cout numérique, le niveau d’endommagement sans avoir recours au calculexact. Le modèle d’endommagement bilatéral n’est pas adapté au cas de chargementsalternés ou périodiques. Par conséquent, la deuxième partie de la thèse est orientée versle développement d’un modèle d’endommagement unilatéral qui donne une meilleuredescription du comportement mécanique lorsque les micro-fissures sont fermées. De plus,dans plusieurs applications industrielles, les structures composites utilisées sont de faibleépaisseur. Par conséquent, elles peuvent avoir naturellement un comportement vibratoirenon-linéaire de type grands déplacements. Le modèle de comportement dynamique engrands déplacements et en présence de la non-linéarité matérielle d’endommagement estdéveloppé et validé. A l’issue de ces travaux de thèse, un outil numérique implémentésur MATLAB® a été développé intégrant deux modèles d’endommagement, bilatéralet unilatéral et une méta-modélisation permettant la localisation et l’estimation del’endommagement ainsi que la prédiction de la réponse dynamique des structures composites, totalement ou localement, endommagées. Le méta-modèle proposé permet deréduire significativement le coût de calcul tout en assurant une bonne précision en termesde localisation et d’estimation du niveau d’endommagement. Cet outil peut s’avérer utilepour diverses applications dans le domaine de surveillance de l’état de santé des structurescomposites. / Composite structures are often exposed to more or less severe dynamic perturbations.These vibrations can develop different forms of damage (fiber fracture, delamination,cracking of the matrix, etc.). Local defects propagate and affect the mechanical propertiesof the structure resulting to modify its global dynamic behavior. These changes can leadto the degradation of the structure and the reduction in its lifetime. This thesis focuseson the implementation of behavior models for the dimensioning of complex structuresintegrating damaged composite sub-structures. The finite element method is used tomodel the linear and nonlinear vibration behavior of these structures where the damageis introduced, initially, via a bilateral model. Since the high computational costs duringthe solving process, a meta-model was developed based on artificial neural networkscoupled with the condensation method of Craig-Bampton. Artificial neural networkspermit to estimate the damage severity at a lower numerical cost without resorting toexact calculation. The bilateral damage model is not adapted to the case of periodic loads.Consequently, the second part of the thesis is oriented towards the development of aunilateral damage model which gives a better description of the mechanical behaviorwhen the micro-cracks are closed. Moreover, in several industrial applications, the usedcomposite structures have small thickness. Therefore, they can naturally have a geometricnon-linear dynamic behavior. The model of dynamic behavior in large displacements andin the presence of material non-linearity of damage is developed and validated. At theend of this thesis, a numerical tool implemented on MATLAB® software was developedintegrating two models of damage, bilateral and unilateral, and a meta-modeling allowingthe localization and the estimation of the damage as well as the prediction of the linear andnon-linear dynamic responses of composite structures, totally or locally, damaged. Theproposed meta-model reduces significantly the computational cost and ensuring a goodaccuracy in terms of localization and estimation of the damage severity. Thereby, thistool can be useful in life-time estimation and monitoring strategies of composite structures.Thèse de

Ce mémoire présente la modélisation, la simulation, l’expérimentation et la conception d’une structure composite intelligente pour des mesures de haute température (jusqu’à 300 °C). Pour ce faire, une fibre à revêtement métallique, particulièrement résistante pour de tels niveaux thermiques, a été considérée et intégrée au sein d’un revêtement d'alumine. La structure composite intelligente se compose alors du substrat, du dépôt et d’un capteur à fibre optique à modulation d’intensité. Pour mener cette étude, une estimation des flux thermiques basée sur le thermogramme expérimental s’est révélée nécessaire afin d’alimenter un modèle numérique. Différents modèles ont ensuite été construits afin d’évaluer les niveaux de températures atteints en surface ainsi que les niveaux de contraintes au sein même du composite. La simulation a montré que le dépôt pouvait thermiquement être considéré comme une couche mince et que la diffusion de la chaleur au sein du dépôt et du substrat était rapide et pouvait être estimée à l'échelle de la milliseconde. La répartition des contraintes est comme on pouvait s'y attendre dépendante du flux incident mais aussi de la géométrie globale du composite. Les contraintes restent relativement uniformes lors de l'échauffement et durant leur propagation mais s’intensifient après le refroidissement. Il s'avère également que les contraintes résultantes ne sont pas symétriques dans la fibre et sont dépendantes de la position de la fibre par rapport au substrat. Après une phase de modélisation des niveaux thermiques et des contraintes susceptibles d’être atteints au sein du matériau, une phase expérimentale consistant à intégrer une fibre optique non fonctionnalisée dans un dépôt d’alumine a donc été réalisée. Les observations microscopiques en surface et en coupe ont été effectuées afin de vérifier l’intégrité de la fibre intégrée. L’adhérence mécanique des fibres a ensuite été mesurée ainsi que l’atténuation optique pendant le processus d’intégration et le comportement thermique de l’ensemble durant des cyclages thermiques. Enfin, un capteur à fibre optique à modulation d’intensité a été conçu par intégration dans un dépôt céramique réalisé par projection thermique. Un système de mesure de la température a donc été construit et les premiers essais de réponse thermique ainsi que le cyclage thermique du capteur de température ont été effectués et analysés. En concluision, cette étude démontre la faisabilité d’une structure composite intelligente par intégration d'un capteur à modulation d’intensité à fibre optique dans un dépôt céramique élaboré par projection thermique susceptible de pouvoir travailler jusqu’à des températures de 300 °C. / This paper presents the modeling, simulation, experimentation and design of a smart composite structrure for high temperature measurements (up to 300 °C). In order to achieve this goal, a high temperature resistant metal coated optical fiber was considered and integrated into alumina coating. The smart composite structure consists of a substrate, a coating and an intensity modulated optical fiber temperature sensor. Firstly, an estimation of heat flux based on a experimental thermogram was firstly carried out in order to feed a numerical modeling. Then, different modelings were built to evaluate the surface temperature levels as well as the composite stress levels. The simulation showed that the composite (substrate and coating) could be considered as a thermally thin medium, the heat propagation within the composite was fast and could be estimated at a scale of millisecond. The stresses remained relatively uniform during the heating process but intensified during the cooling process. The modeling also showed that the stresses are not symmetrical in the fiber and depend on the position of the fiber relative to the substrate. After a modeling evaluation of the thermal levels as well as the stresses that may be achieved in the composite, an experimental step integrating a optical fiber into a thermal coating was carried out. Microscopic observation of surface and cross section were conducted in order to analyze the characteristics of the integrated fiber. The mechanical strength of the integrated fiber was then measured and the optical attenuation during the integration process as well as the thermal behavior of the integrated fiber during the thermal cycling were evaluated. Finally, an intensity modulated optical fiber temperature sensor was designed and integrated into ceramic coating by thermal spraying. A temperature measuring system was designed and the first tests of the thermal response as well as thermal cycling of temperature sensor were carried out. This study demonstrates the feasibility of designing a high temperature resistant smart composite structure by integrating an intensity modulated optical fiber temperature sensor in a ceramic coating elaborated by thermal spraying.

Fiber orientation angle stands out as one of the most effective design variables in the design optimization of composite structures. During the manufacturing of the composite structures, one can change the fiber orientation according to the specific design needs and constraints to optimize a pre-determined performance index. Fiber placement machines can place different width tows in curvilinear paths resulting in continuous change of the fiber orientation angle in a layer of the composite structure. By allowing the fibers to follow curvilinear paths in the composite structure, modification of load paths within the laminate can be obtained. Thus, more favorable stress distributions and improved laminate performance can be achieved. Such structures are called as variable stiffness composites structure. This thesis presents a fundamental study on the discrete fiber angle and continuous fiber path optimization of composite structures. In discrete fiber angle optimization, application of different analysis/optimization tools is demonstrated for optimum fiber angle optimization at the element level for both orthotropic and laminated composite structures. In the continuous fiber path optimization, which can be produced with fiber placement machines, optimized fiber paths are determined for different case studies. Continuous fiber path optimization is performed by means of an interface code that is developed. It is hard to find the global optimum for complex optimization problems with hundreds of design variables. In order to find the global optimum solution for such complex optimization problems, a gradient based optimization algorithm is not appropriate because there will be a lot of local minima for the problem and gradient based optimization algorithms may be stuck at the local minimums. Therefore, an evolutionary algorithm is a better solver for such kind of complex optimization problems. In this thesis, genetic algorithm, an evolutionary algorithm, in MATLAB Optimization Toolbox is used for the optimizer and commercial finite element program Nastran is used for the structural solver. For the continuous fiber path optimizations these two programs are integrated with the interface code that is developed. Manufacturing constraints of a typical fiber placement machine is also included in the constraint definition of continuous fiber path optimization. By coupling of Nastran finite element solver and MATLAB genetic algorithm tool, with the manufacturing constraint for the fiber placement machines, the first buckling load of a continuous fiber composite plate is increased %22 with respect to a composite plate with zero degree orientations.

Usualmente, em situações práticas de projeto de lajes mistas, procura-se uniformizar ao máximo a espessura das fôrmas de aço, normalmente por razões econômicas (produção em larga escala). Entretanto, em alguns casos, há a necessidade de se especificarem algumas fôrmas com maior espessura, solução essa pouco competitiva no mercado brasileiro. Uma alternativa economicamente interessante em relação ao aumento de espessura é a inserção de armadura adicional, mantendo-se assim a espessura padrão (em geral 0,80 mm) e obtendo-se aumento da área de aço por meio de vergalhões. No entanto, por se tratar de uma solução inusual, o comportamento estrutural das lajes mistas com armadura adicional e seus critérios e diretrizes de dimensionamento não são previstos em normas e manuais técnicos: a ABNT NBR 8800 (2008, p. 226) e o Eurocode 4 (2004, p. 104) mencionam que, caso haja armadura para resistir ao momento fletor positivo, a formulação apresentada deverá ser adequadamente ajustada, mas não apresentam os respectivos critérios e equacionamentos. O ANSI/ASCE 3-91 (1992), o CSSBI S2-2008 (2008) e o ANSI/SDI C-2011 (2011) não mencionam a possibilidade de armadura adicional. Diante desse cenário, investigou-se o comportamento estrutural de lajes mistas com vergalhões e, por meio de uma extensão matemática das formulações já existentes para o caso sem armadura, foram propostos critérios de dimensionamento para os estados-limites últimos (momento fletor e cisalhamento longitudinal) e de serviço (deslocamento vertical). Foram realizados ensaios de flexão em doze protótipos de lajes mistas de dimensões usuais, sendo oito sem barras adicionais e quatro com, variando-se as dimensões (altura e vão, conforme Eurocode 4 (2004)) e com quatro taxas de armadura. A partir desses resultados, pôde-se analisar o comportamento estrutural dos protótipos com armadura adicional, os quais apresentaram ductilidade e capacidade consideravelmente maiores que as correspondentes lajes sem as barras. Por fim, também foram validadas as formulações referentes ao cisalhamento longitudinal (extensões do Método m-k e do Método da Interação Parcial) e ao deslocamento vertical, para os casos mais usuais. / Usually, on the design of composite slabs with profiled steel decking, it is tended to standardize as much as possible the thickness of the steel decking, generally because of economic reasons (large-scale production). Nevertheless, in a few cases it must be necessary to specify thicker steel decking, which is not a competitive solution in the Brazilian market. An economic alternative regarding the increase of thickness is the insertion of additional bottom reinforcement, thus, keeping the standard thickness (in general 0.80 mm) and obtaining the steel area increment through rebars. Notwithstanding, since that is an unusual solution, the structural behavior of composite slabs with additional reinforcement, their criteria and design guidelines are not provided in standards and technical manuals: ABNT NBR 8800 (2008) and Eurocode 4 (2004) state that, if there are additional bars to resist positive bending moment, the formulation should be adapted, however they do not present the respective criteria and equating. CSSBI S2-2008 (2008), ANSI/ASCE 3-91 (1992) and ANSI/SDI C-2011 (2011) do not mention the possibility of using additional reinforcement. In this scenario, the structural behavior of composite slabs with rebars was investigated and, through a mathematic extension of the formulation already used to the unreinforced situation, design criteria were proposed for the ultimate (flexure and longitudinal shear) and serviceability (deflection) limit states. In addition, flexure tests were carried out in twelve composite slabs with usual dimensions, eight of those without additional bars and four with, following the recommendations by Eurocode 4 (2004) about the variation of the dimensions (height and span), with the latter having four reinforcement rates. With the results of those tests, the structural behavior of the reinforced prototypes was analysed, which have showed considerably higher ductility and resistance when compared to those with the unreinforced ones. Finally, the formulations for the usual cases related to longitudinal shear (extensions of the m-k Method and the Partial Interaction Method) and deflection were validated.

Este trabalho tem por objetivo investigar a contribuição da armadura para a capacidade resistente de vigas mistas parcialmente revestidas, bem como sua eficiência para promover o comportamento conjunto aço-concreto, imprescindível para a obtenção de vigas mistas. O estudo engloba uma investigação experimental com ensaios de vigas sob flexão em quatro pontos e uma simulação numérica utilizando o pacote computacional DIANA®, visando obter dados do comportamento de vigas mistas parcialmente revestidas com armadura longitudinal. Foram ensaiados quatro modelos de viga mista parcialmente revestida e duas variáveis foram analisadas: taxa de armadura longitudinal no concreto e posição dos conectores tipo pino com cabeça. Os resultados experimentais mostraram a eficiência do conjunto armadura-conector para o aumento da capacidade resistente à flexão e para a promoção da interação aço-concreto. A simulação numérica teve concordância satisfatória com os resultados experimentais obtidos. / This study aims to investigate the contribution of the steel bars to the flexure capacity and to promote the composite behavior in partially encased composite beams. The study includes an experimental investigation of partially encased beams under bending in four points and a numerical simulation using the computer package DIANA® to collect data from the behavior of partially encased composite beams with longitudinal reinforcement. Four models of partially encased composite beams were tested and two variables were analyzed: rate of longitudinal reinforcement in concrete and position of stud bolts. The experimental results showed the efficiency of the junction between reinforcing bars and stud bolt to the increase the bending capacity of the partially encased beam and to obtain the steel-concrete interaction. The numerical simulation has good agreement with the experimental results.

The first chapter introduces the basic principles governing the phenomenon like ferroelectricity, piezoelectricity and pyroelectricity, which influences the material properties for its device applications. An effort is made to examine the present status of material issues, measurement techniques and applications pertaining to the lead based PZT type systems. This chapter also highlights the objectives and the scope of work. The second chapter deals with the various basic experimental techniques and principles adopted for the synthesis and characterizations of materials which include phase and quantitative analysis by X-ray diffraction, density measurements, microstructures by scanning electron microscopy, electrical properties such as dielectric permittivity, dielectric loss, and piezoelectricity by impedance analyzer and piezometer etc. The materials were synthesized via two step solid state reaction by adopting a low temperature calcinations route. Further, hot processing was employed for densification and better control of microstructure of the ceramics. In the third chapter PZT1-x –PZNx (x=0, 0.1, 0.2 & 0.3) compositions prepared by the single step low temperature calcination method have been described. It is seen that the pyrochlore free perovskite phase could be obtained up to x=0.2 compositions. The effect of additives like Li and Mn on the structure, sinterability, microstructure, density and dielectric properties has been investigated. The improvement in densification and ferroelectric properties were observed for Li addition favor tetragonal phase while Mn addition compositions were inclined to pseudocubic phase. Further, the addition of Mn led to the significant decrease in Tc than the parent compositions compared to Li added compositions. In the fourth chapter, the X-ray diffraction data on pbzrx Ti1-x O3 (PZT) for x=0.48 to 0.52 are presented. High resolution x-ray studies for composition x=0.5 show the MPB which consists of monoclinic Zr rich studies and tetragonal Ti rich phase at room temperature. The refined structural parameters for MPB compositions have been obtained using least square Rietveld refinement program, FULLPROF 2006. The evolutions of lattice parameters of the system were also studied with respect to the temperature. The phase transformation in the system has been analyzed by x-ray diffraction pattern and dielectric measurements. The monoclinic phase transforms to tetragonal phase at 270oC after which the tetragonal phase transforms to paraelectric cubic phase at 370DoC. Dielectric properties show signature of the phase transformation. Hence, it is concluded to pole the MPB samples below 270o C to gain the advantage of increased ease of polarization reorientation for monoclinic phase. The fifth chapter deals with the systematic structural investigation on PZT1-y-PNZy (PZT-PNZ) and PZT1-y-PMNy (PZT-PMN) systems. In this chapter, an effort has been made to determine quantitatively the MPB phase contents and variation in Zr/Ti ratio of PZT-PZN and PZT-PMN systems. High resolution XRD data has been used for quantitative phase analysis using FULLPROF 2006. The correlation between the width of MPB and grain size has also been discussed for these systems. It is found that the addition of PMN and PZN to PZT system shifts the MPB towards pbZrO3 (PZ). The MPB can be regained by tuning the Zr/Ti ratio in the system. Further, there exists an inverse relation between the grain size and coexistence region in the system. It is seen that the MPB range is from x=0.48 to 0.58 and x=0.44 to 0.58 for 10% and 20% PZN concentration respectively. Similar trend has been obtained for the PZT-PMN system. The MPB ranges from x=0.46 to 0.53 and x=0.42 to 0.50 for 10% and 20% PMN respectively. The broadening of coexistence width is attributed to the lower grain size of our samples synthesized by adopting low temperature calcinations route. The sixth chapter deals with the hot pressing technique employed (adopting low temperature calcinations) for the synthesis of various PZT-PMN compositions with an intention of obtaining highly dense piezoceramics with fine, homogeneous and uniform microstructure. It also describes the dielectric, pyroelecrtic and pi ezoelectric properties were enhanced by hot processing technique. Li and Mn addition further improved the properties of the system. The seventh chapter investigates various nominal compositions of PZT-(Li, Nb) compositions based on certain assumptions. The attempt was made to introduce Li at A site and B site of ABO3 perovskite lattice. The ball milled, calcined powders were densified at<1000oC using hot pressing technique to prevent Li and Pb loss. High density ceramics have been studied for structural, dielectric, piezoelectric and pyroelectric properties. Through the clear cut evidence for the identification of Li site in the PZT system could not be established but the system which were synthesized under the assumption that Li substitutes A-site of the perovskite, favored the tetragonal phase and led to the enhancement in the dielectric, pyroelectric and piezoelectric properties. Further, their transition temperature was higher compared to the compositions where Li was tried to substitute B-site, which makes them promising candidates for transducer applications. The key finding in this thesis has been carried out by the candidate as part of the ph. D. programme. She hopes that this would constitute a worthwhile contribution towards the understanding of the behavior of lead based perovskites and in tailoring the properties of these ceramics towards device applications by the introduction of suitable additives in the system.

The aim of diploma thesis was to design alternative of composite road bridge in Trenčín. The bridge beam is designed as continuous with theoretical span of 65 m + 106 m + 65 m. Permanent load, climatic load (uniform and nonuniform temperature variation, windload), shrinkage, differential settlement and traffic load were taken into consideration according to Eurocodes. Technical report, static report, drawings, bill of quantities are included. Computational model for evaluation of internal forces was carried out in SCIA Engineer software.

This diploma thesis is deals with design of steel structure of a shopping centre. The object is situated in the Ostrava and has a rectangular and semicircle ground plan. The total ground plan dimensions are 72,5 x 55,0 m. The maximum height of a building is 18,75 m. The object has three storeys above ground. The material of main construction is steel grade S235. The ceilings are constructed from a steel-concrete beams. The roof above central part of the object has shape of a circular arch; above the other part of the building is a pitched roof. The design of main structures was made for two variants. The design of connections, anchorage and drawing documentation were made for the preferable variant.