No description available.

Since 1 January 2010 it is a requirement to use the European standards, Eurocodes, in Sweden when constructing bridges. One chapter that has caused an extra amount of problems for the engineers is the one about fatigue analysis, which resulted in us doing this thesis. To do this we had to read all of the Eurocodes that direct, or indirect deals with fatigue and calculating of such. We have read the background documents for the Eurocodes and master’s thesis in the subject. We also studied the calculations of bridges constructed by different construction firms. We have chosen to limit the thesis to discuss only road bridges made of concrete due to the lack of method for verification of concrete in the national appendix. There is a need for clarification of what method to use. To make sure that this thesis will be of use to the constructors, we have presented easy-to-use instructions for how to calculate fatigue on reinforced concrete bridges. We have also calculated an example of a bridge in two spans where we present the calculations in Excel more thoroughly. Fatigue of concrete is in many cases not the critical factor and it can most often be verified by simple methods. The concrete reinforcement is more often the subject to fatigue, but verification can relatively easy be done with the method described in the national appendix if a good Excel- or MathCAD sheet is used. / Sedan den 1 januari 2010 är det krav i Sverige att för bro- och anläggningskonstruktioner använda de nya europeiska standarderna, eurokoder, för dimensionering. Ett kapitel som vållat stora problem för brokonstruktörer är kapitlet om utmattningslaster och dimensionering för dessa vilket ledde till att vi gjorde detta examensarbete. Vi har läst igenom de eurokoder som direkt och indirekt behandlar utmattning och utmattningsberäkningar, granskat bakgrundsdokument till eurokoderna samt läst examensarbeten som handlar om utmattning. Dessutom har vi också granskat beräkningar från ett flertal broar som olika konsultföretag konstruerat. Vi har valt att avgränsa arbetet till att enbart handla om utmattning av vägbroar i armerad betong. Detta har vi gjort för att metoder för verifiering av betongen i vägbroar inte är definierade i de nationella tilläggen till eurokoderna. Därför behövs ett förtydligande av vilka metoder som är lämpliga att använda. För att konstruktörer ska ha praktisk nytta av detta examensarbete, har vi redovisat en beräkningsgång med kommentarer och dessutom utfört egna beräkningar för en förenklad variant av en plattbro i två spann där vi redovisar beräkningarna i Excel mer ingående. Vad vi har kommit fram till är att armeringen ofta är mer utsatt för utmattning än betongen men verifieringsmetoden beskriven för armeringen i det nationella tillägget är en metod som är relativt lätt att använda med ett bra Excel eller MathCAD-ark.

La pratique courante de la conception des ouvrages d'art est fortement orientée par la phase de construction. Traditionnellement, la conception des ouvrages consiste à retenir un dimensionnement qui permet d'atteindre un coût initial de construction le plus faible possible tout en respectant des exigences prescrites pour une durée de fonctionnement donnée. Cette approche est aujourd'hui revisitée pour chercher à intégrer tout le cycle de vie de l'ouvrage, c'est-à-dire à considérer toutes les étapes de sa vie depuis la conception jusqu'à la fin de vie en service. En effet, les activités liées au cycle de vie de l'ouvrage durant les phases d'exploitation, de maintenance/réhabilitation, et de fin de vie génèrent des impacts tant sur le plan économique que sur les plans environnementaux et sociétaux, bien plus importants que la simple phase de conception/construction. Chaque option de dimensionnement peut être associée à un cycle de vie différent et donc à des impacts différents. Pour cette raison et dans une approche de développement durable, cette thèse propose d'analyser les ouvrages dans leur cycle de vie selon trois axes : économique, environnemental et sociétal. Pour cela, une famille d'ouvrage particulière a été retenue : les ponts mixtes acier-béton. Une analyse performantielle est également effectuée pour permettre de prendre en compte différents scénarios de maintenance. Finalement, une procédure d'optimisation et une analyse multicritère sont proposées pour évaluer l'ensemble des variantes de conception et permettre d'avoir une vision globale qui aide les maîtres d'ouvrage et les gestionnaires lors de la prise de décision / The current practice in structural design is strongly impacted by the construction stage. Traditionally, the design process aims at selecting the solution with the lowest initial construction cost while fulfilling prescribed requirements during a fixed service life. This approach is now revisited to integrate the whole “life-cycle” of the structure, i.e to consider the structure from the design step to the end of the service life. Indeed, activities related to the structure life-cycle such as operation, maintenance/rehabilitation and end-of-life generate economic, environmental and societal impacts, which may be more significant than those at the design/construction of the structure. Each design solution might be associated with a different life-cycle, and then with differents impacts. For this reason and within an approach of sustainable development, this PhD work proposes to analyze structures during the overall life-cycle of the structure in accordance with three axes : economic, environmental and social. A performance-based analysis is also performed to take into account different maintenance strategies. Finally, a multi-objective optimization process and a multi-criteria analysis are proposed to assess all design solutions and have a global vision that helps bridge owners and managers in the decision making process

The design approach is currently very diverse for glass. It differs greatly between European countries and there is not one definite method for the design of glass components. Research in this field has a potential for better design optimization and industry professionals express a limitation of tools and knowledge about glass structure design.The purpose of this study is to analyze glass balustrades with point-fixings and to test a structural verification approach using a Finite Element (FE) software. The theory provides insight of glass as a structural material, different interlayers used for laminated glass, joints and connections, as well as design standards, concepts and regulations. Different models of varying configurations and geometries are created from the evaluation of balustrades with point-fixings available on the Swedish market and the theory. The models represent a glass balustrade with 4- or 6-point-fixings and is regarded as a fully toughened laminated glass component with different stiff and standard interlayers. The structural analysis of point-fixed glass balustrades on the Swedish market indicated a lower stress and deflection resistance capacity than the pre-normative Eurocode criterion. Based on the FE calculations, some guidelines for fulfilling the criterion are proposed.To make glass more generally applicable as a load-bearing material, the limitations of the FE-software, and how the parameters affect the calculation results needs to be taken into consideration. In order to evaluate the interlayers used for the model, a parametric study using FE-analysiswas carried out, in which the maximum stresses and deflections for several variations were calculated. A sensitivity analysis of the balustrade was conducted to evaluate various geometric and material parameters and how they affect the FE software-based model. Comparisons of guidelines and national codes for simplified hand-calculation and the FE-approach were made to obtain some understanding of calculation methods used in the glass industry and to evaluate the results of the structural analysis. The study suggests that the FE approach is an effective method for a relatively quick and easy verification of glass balustrades.

Eurokoderna som utgör svenska normer för verifiering av bärförmåga, stadga och beständighet är i en fortgående utvecklingsfas och är ibland svåra och tidsödande att tillämpa i konstruktionsarbetet. Normerna anpassas kontinuerligt efter att frågor debatteras i branschen och det är viktigt att användarna av Eurokoderna håller sig uppdaterade. Svårtolkade begrepp och definitioner tillsammans med en omständig struktur i Eurokoderna skapar merarbete för användarna. Detta examensarbete sammanställer nödvändig information samt undersöker och utvecklar tillhörande begrepp för två ämnen, lastnedräkning och stomstabilitet. Examensarbetet kommer likt en handbok kunna användas i vardagligt konstruktörsarbete för att snabbt hitta rätt i Eurokoderna och bidra till att reda ut oklarheter kring de två berörda ämnena. Beräkningsexempel är upprättade som praktisk vägledning för respektive ämne där Eurokoderna tillämpas och hänvisas till. Examensarbetet är inriktat på handberäkningar. Dessa handberäkningar kan ligga till grund för initiala bedömningar av ett bärverks dimensioner och övergripande stabilitet men även vara ett stöd i beräkningar i bygghandlingsskeden. / The Eurocodes, which serve as the Swedish standards for verification of mechanical resistance and stability, are in an ongoing development phase and are sometimes difficult and time consuming to apply in the design process. The standards are continuously adapted to issues debated in the industry and it is important that users of the Eurocodes keep themselves up to date. Indistinct terms and definitions in the Eurocodes create, together with an inconvenient structure, extra work for users. This thesis compiles the necessary information and examines and elaborates terms related to two topics, load distribution and structure stability. Similar to a handbook, this thesis can be used in designer’s everyday work to quickly find the right Eurocodes and help sort out the confusion related to the topics in this thesis. Calculation examples are given as a practical guide where Eurocodes are applied and referred to. The thesis is focused on hand calculations. These hand calculations could act as a base for initial assessments concerning structure dimensions and overall stability as well as a guide during final calculations for construction drawings.

En pelarfot är en stål-till-betongknutpunkt som består av en fotplåt med insvetsad stålpelare och grundskruvar som gjuts ner i betonggrundkonstruktionen. Pelarfoten används till att överföra lasten från bärande pelare ner till grunden och grundskruvarna hjälper till att ta upp skjuvkrafter samt dragkrafter som uppstår av böjmoment. Vid dimensionering av pelarfötter finns principer och råd för beräkning att hämta från Eurokoderna. Dock kan det ta tid att hitta alla anvisningar som finns spridda mellan olika Eurokoder. I praktiken är det effektivt att använda något av de designprogram som är specialiserade förknutpunktermed automatisk beräkningsfunktion. I denna rapport studeras beräkningsprinciper enligt Eurokoderna som underlag förförståelse av dimensionering av en pelarfot. Sedan används designprogram för att dimensionera pelarfoten. Målet är att ta reda på vilket eller vilka program som är lämpligast för dimensionering av pelarfötter. Programmen som används är Peikko Designer, IDEA StatiCa och FEM-Design Steel Joint där alla har sina egna beräkningsrutiner för att uppfylla Eurokoderna. Utvärderingen gjordes endast för pelarfotstypen PF3 med samma lastkombinationer i tre fallstudier. För grundskruvar användes standardskruvar från Peikkos sortiment vid förankringen. Resultatet visade sig att programmen är lämpligast för sitt användningssyfte. Peikko Designer är lämpligast för beräkning av sina egna grundskruvar. IDEA StatiCa är lämpligast för dimensionering av pelarfötter i allmänhet med större noggrannhet med hjälp av FEM. FEM-Design Steel Joint är däremot inte längre lämpligt vid användning på grund av en gammal standard. / A column base is a steel-to-concrete connection that consists of a base plate welded to a steel column and anchor bolts casted into the concrete foundation. The column base is used to transfer loads from the load-bearing column to the foundation and the anchor bolts help to absorb shear forces as well as tensile forces that arise from bending moments. When designing a column base, there are calculation principles and advice to be taken fromtheEurocodes. However, it can take time to find all the instructions indifferent to Eurocodes. In practice, it is efficient to use design programs that specialize in steel connections with automatic calculation functions. In this report, calculation principles according to the Eurocodes are studied as a basis for understanding the design of a column base. Then design programs are used to verify the column base. The goal is to find out which program or programs are most suitable for practical use.  The programs used are Peikko Designer, IDEA StatiCa and FEM-Design Steel Joint, where all of which have their own calculation routines for complying with the Eurocodes. The evaluation was made only considering the column base type PF3with the same load combinations in three case studies. For anchor bolts, Peikko’s standard anchor bolts are used for anchoring. The result showed that the programs are most suitable for their intended use. Peikko Designer is most suitable for calculating its own anchor bolts. IDEA StatiCa is most suitable for design of column bases in general with greater accuracy using FEM. However, the FEM-Design Steel Joint is no longer suitable for use due to implementation of an old standard.

This thesis is about determining the risks of positioning swimming pools on top of high-rise buildings.Pursuing this determination, computational simulations of constructed structural models in a finiteelement model software called RFEM have been analyzed. In further pursuit of wanted results comingfrom the computational software, the models have acquired relevant theory regarding both swimmingpools and high-rise buildings respectively to obtain realistic approximations of equivalent results if themodels were real life structures. Thence analytical observations and measures of each structural modelcontaining different positions of the swimming pools are generated, in several degrees, differentpossibilities of risks of failure are possible. Results have been compared out of design of swimmingpools and high-rise buildings in an initial stage of background and thereafter set as input values for themodeling where following perspectives have been analyzed:• Structural deformations,• Internal forces,• Utilization ratios, and• Mode shapes.Further analysis of social-, economic-, and environmental sustainability have been deliberated. Thus,in conclusion of this thesis, swimming pools positioned on top of the structure core or at center of theplan section tend to harm the stability of the structure likewise if the positioning of the swimming poolare cantilevered completely over the edge of the rooftop. More suitable design would either bepositioning the swimming pool attached to the core of the structure meanwhile cantilevered over theedge or integrated entirely along the edge.The results showed that some of the overhanging swimming pools pass the requirements of theEurocode. This will result in the columns experiencing a utilization which exceed its capacity. Thecolumn utilization was shown to behave differently depending on where the swimming pool was placedon the top floor. Furthermore, it was also a difference between the structures studied as dimensions ofthe members required either more or less depending on the form the structure had. The reaction of theswimming pool could be observed to behave as a stiff part of the structures with the deformation mostlybeing located at the slabs. The internal forces developed in the members due to the swimming poolaffected the columns at the bottom floors the most. The thesis finally shows how much is needed forthe worst case of each structure to pass the requirements. This resulted in different dimensions for themembers where the smaller structure (structure model 1) needed bigger dimensions and the largerstructure (structure model 2) needed smaller dimensions compared to the originally based dimensions.The social, economic, and environmental impact of the structures showed that the larger structureswould release more carbon dioxide than the smaller structures. The social aspect was treated moreregarding the safety and the experience of the user of the facility of swimming pool. The reinforcementvaried the most between the structures with the concrete being mostly the same for the two differentstructures made, in which an impact was made for both the economic and the environmental. Here itwas shown that in order to pass the requirements of the Eurocodes the impact on the climate needed tobe considerable different.

En situation d’incendie, la dégradation des propriétés mécaniques des matériaux constitutifs d’une structure peut sensiblement en modifier le comportement global. Ainsi, lors d’essais au feu ou de sinistres réels, des flèches significatives sont observées sans ruine globale du plancher. Ceci traduit l’activation d’un mécanisme basé sur une borne supérieure de plasticité en grands déplacements et appelé effet membrane. Ainsi, malgré la perte des propriétés du béton, de l’acier d’armatures et de l’acier de construction des poutres connectées à une dalle en béton armé ou mixte acier-béton, la capacité portante de cette dalle se définit comme une fonction croissante de sa flèche. En pratique, le comportement complexe des planchers mixtes acier-béton peut être appréhendé par des modèles dits simplifiés ou avancés, suivant le niveau de précision souhaité. La méthode analytique FRACOF permet par exemple d’étudier un plancher global à température élevée, en se basant sur les modèles de comportement simplifiés des matériaux, acier et béton, définis dans les Eurocodes. Par cette méthode, la capacité portante d’une dalle peut alors être déterminée en tenant compte des profilés métalliques connectés à la dalle, et de l’activation d’un effet membrane en grands déplacements. Cette méthode analytique a été validée par une comparaison à des modèles éléments finis, ainsi qu’à des résultats d’essais au feu en grandeur nature. Elle est applicable à des profilés en acier laminé à chaud avec des portées pouvant atteindre 20 m. Or le franchissement de ces portées nécessite des sections de poutre à forte inertie, afin de limiter les flèches du plancher en service. Pour limiter la quantité d’acier que requerraient de telles poutres, le recours à des poutres cellulaires est une solution pratique et esthétique. Un modèle élément finis de poutres cellulaires en acier seul et mixtes est proposé dans le cadre de la thèse de doctorat. Le comportement thermo-mécanique des poutres cellulaires en acier seul est modélisé sous le code Cast3M. Les poutres mixtes sont modélisées en combinant un calcul de transfert thermique sous Cast3M et une analyse mécanique sous ANSYS. Les poutres en acier et la dalle en béton ou mixte sont représentées par des éléments de type coque. Les connecteurs sont représentés par des éléments de type poutre. Ce modèle tridimensionnel tient par ailleurs compte des non-linéarités matérielle et géométrique. Il est confronté à des résultats d’essais à températures normale et élevée. La validation du modèle est suivie d’une comparaison à une méthode analytique existante pour en vérifier la précision et le degré de conservatisme. Les poutres cellulaires sont ensuite étudiées en tant que partie intégrante de planchers mixtes acier-béton sous incendie. Un essai en grandeur nature sous feu réel met en évidence l’activation d’un effet membrane en présence de poutres cellulaires non-protégées, sans ruine du plancher. Les résultats de l’essai sont utilisés pour calibrer un modèle élément fini tridimensionnel. La calibration est effectuée en s’appuyant sur la distribution des températures dans les différents composants du plancher, la durée de résistance au feu, la forme des déformées et les modes de ruine. Ensuite, le modèle, qui peut reproduire le comportement thermo-mécanique d’un plancher mixte, est utilisé pour évaluer une proposition d’extension de la méthode FRACOF à des planchers mixtes comportant des poutres cellulaires. / In a fire situation, the decrease of the material properties of a structure can significantly modify its overall behaviour. Hence, during fire tests or real fires, very large deflections can be observed on a floor without any global collapse. This highlights the activation of a large-displacement plastic upper bound mechanism called membrane action. Thus, in spite of the property loss of concrete, reinforcement steel and constructional steel of the beams connected to a reinforced concrete or composite slab, the load bearing capacity of this slab is defined as an increasing function of its vertical deflection. In practice, the behaviour of composite steel and concrete floors can be assessed with simplified or advanced models, depending on the expected level of precision. For instance, the analytical method named FRACOF enables to study a whole floor at elevated temperatures, on the basis of the Eurocodes simplified models for the behaviour of steel and concrete. With this method, the load bearing capacity of a slab can then be estimated taking account of steel profiles connected to the slab and tensile membrane action in large displacements. This analytical method has been validated against finite elements models as well as results from full scale fire tests. It applies to hot-rolled steel profiles spanning up to 20 m. However, such spans require sections with a great moment of area to limit the floor deflection in serviceability state. In order to limit the amount of steel required, cellular beams can be utilized as a practical and aesthetical solution. A finite element model for steel and composite steel and concrete cellular beams is proposed in the scope of the PhD thesis. The thermo-mechanical behaviour of steel cellular beams is modelled under Cast3M code. Composite beams are modelled combining a heat transfer calculation under Cast3M to a mechanical analysis under ANSYS. The steel beams and the reinforced or composite slab are modelled with shell elements. The shear studs are modelled with beam elements. Besides, this 3D model takes into account both material and geometrical nonlinearities. It is compared with tests results at both normal and elevated temperatures. Once validated, the model is compared to an existing analytical method in order to check the precision and the level of conservatism of the latter. Then, cellular beams are studied as part of composite steel and concrete floors in a fire situation. A full-scale natural fire test puts into evidence tensile membrane action with unprotected cellular beams, without any overall collapse. The test results are used for calibrating a 3D finite element model. This calibration relies on the temperature distribution in the different parts of the floor components, the fire resistance degree, the deformed shape and the failure modes. The model, which can reproduce the thermo-mechanical behaviour of a composite floor, is then utilized for assessing an extension proposal of the FRACOF method to composite floors made of cellular beams.

It is of interest to investigate extended usability of Saab’s Deployable Aircraft Maintenance facility(DAM) with respect to Eurocode standards. One of the features of the deployable hangar is that it shouldcomply with the structural strength standards for permanent buildings which requires compliance withEurocodes.Eurocodes are European standards which deals with the development of building and structural design.Compliance with Eurocodes works as a proof of requirement for mechanical strength, stability andsafety of structures. The Eurocodes were created by the European Committee for Standardization withthe intent to simplify technical obstacles and enable trade within Europe and elsewhere.The thesis has resulted in the creation of a Finite Element Model (FE-Model) of the deployable hangar,for which different loading combinations have been applied. From the FE-results, trade-off curves havebeen generated that show the effect that the different loading conditions have on the differentcomponents of the hangar. This is done for the current configuration of the hangar and for differentproduct variants. The analysis includes the effects of increased load levels.From the trade-off curves it is possible to see to what extent the hangar can withstand increased load.This is being measured with a Eurocode ratio. It has been found that the Eurocode ratio is directlydependent on increase of loads i.e. increased loads give a linear increase in Eurocode ratio for most ofthe components studied. The product variants consists of different lengths of the hangar. From the studyit has been found that adding or removing sections does not have a substantial effect on the strength ofthe hangar and the Eurocode ratio mostly remains constant. In addition the most critical componentshave been found and design suggestions have been proposed to improve the strength of the hangarwithin compliance with Eurocodes.

This paper presents the details of an experimental investigation on the behaviour of axially loaded concrete-filled stainless steel elliptical hollow sections. The experimental investigation was conducted using normal and high strength concrete of 30 and 100 MPa. The current study is based on stub column tests and is therefore limited to cross-section capacity. Based on the equations proposed by the authors on concrete-filled stainless steel circular columns, a new set of equations for the stainless steel concrete-filled elliptical hollow sections were proposed. From the limited data currently available, the equation provides an accurate and consistent prediction of the axial capacity of the composite concrete-filled stainless steel elliptical hollow sections.