No description available.

As últimas quatro décadas foram importantes para o desenvolvimento da malha rodoviária brasileira. O sistema de rodovias do país recebeu incentivos financeiros à sua expansão e diversas soluções estruturais para pontes e viadutos foram criadas a fim de atender à demanda de infraestrutura. Em contrapartida, a carência de programas de manutenção preventiva tem causado um crescimento significativo no número de estruturas desse tipo que se encontra em estágio avançado de deterioração. Dessa maneira, esta dissertação propõe um plano de monitoramento de curta duração para monitorar o comportamento estrutural de uma ponte rodoviária curva de concreto armado já em serviço. A partir da revisão do estado-da-arte no assunto, são apresentados os tipos de monitoramento, as possíveis grandezas a serem monitoradas e as ferramentas para medi-las, assim como suas vantagens e desvantagens. A fim de avaliar estruturalmente o comportamento da ponte e auxiliar no plano de monitoramento, uma hierarquia de seis modelos numéricos é desenvolvida. Então, o plano de monitoramento proposto é aplicado na ponte sob estudo para aquisição de dados, que são posteriormente tratados e confrontados com os dois modelos numéricos mais complexos da hierarquia em um processo de análise e calibração desses modelos. Dessa análise, é possível mostrar a representatividade dos modelos desenvolvidos e a relação entre complexidade do modelo, número de parâmetros adotados para a representatividade da estrutura e convergência de resposta. / The last four decades were important for the development of the Brazilian highway system. Investments were made on the expansion of highways and many structural solutions for bridges and viaducts were developed in order to attend the countrys demand. In contrast, the lack of preventive maintenance programmes has caused a significant increase in the number of those structures found in advanced deterioration stage. Thus, this thesis aims to suggest a short-term monitoring plan to monitor the structural behaviour of a curved highway concrete bridge in service. From studies on state-of-the-art in monitoring, it is presented its types, magnitudes and tools to measure them structures, as well as their advantages and disadvantages. In order to assess the structural behaviour of the bridge and support the monitoring plan, a hierarchy of six numerical models is developed. Then, the proposed monitoring plan is applied to the bridge under study for data acquisition. Afterwards, this data is processed and compared with the two more complex numerical models of the hierarchy in a process of analysis and calibration of these models. From this analysis, it is possible to show the representativeness of the developed models and the relationship between model complexity, number of parameters and convergence.

As últimas quatro décadas foram importantes para o desenvolvimento da malha rodoviária brasileira. O sistema de rodovias do país recebeu incentivos financeiros à sua expansão e diversas soluções estruturais para pontes e viadutos foram criadas a fim de atender à demanda de infraestrutura. Em contrapartida, a carência de programas de manutenção preventiva tem causado um crescimento significativo no número de estruturas desse tipo que se encontra em estágio avançado de deterioração. Dessa maneira, esta dissertação propõe um plano de monitoramento de curta duração para monitorar o comportamento estrutural de uma ponte rodoviária curva de concreto armado já em serviço. A partir da revisão do estado-da-arte no assunto, são apresentados os tipos de monitoramento, as possíveis grandezas a serem monitoradas e as ferramentas para medi-las, assim como suas vantagens e desvantagens. A fim de avaliar estruturalmente o comportamento da ponte e auxiliar no plano de monitoramento, uma hierarquia de seis modelos numéricos é desenvolvida. Então, o plano de monitoramento proposto é aplicado na ponte sob estudo para aquisição de dados, que são posteriormente tratados e confrontados com os dois modelos numéricos mais complexos da hierarquia em um processo de análise e calibração desses modelos. Dessa análise, é possível mostrar a representatividade dos modelos desenvolvidos e a relação entre complexidade do modelo, número de parâmetros adotados para a representatividade da estrutura e convergência de resposta. / The last four decades were important for the development of the Brazilian highway system. Investments were made on the expansion of highways and many structural solutions for bridges and viaducts were developed in order to attend the countrys demand. In contrast, the lack of preventive maintenance programmes has caused a significant increase in the number of those structures found in advanced deterioration stage. Thus, this thesis aims to suggest a short-term monitoring plan to monitor the structural behaviour of a curved highway concrete bridge in service. From studies on state-of-the-art in monitoring, it is presented its types, magnitudes and tools to measure them structures, as well as their advantages and disadvantages. In order to assess the structural behaviour of the bridge and support the monitoring plan, a hierarchy of six numerical models is developed. Then, the proposed monitoring plan is applied to the bridge under study for data acquisition. Afterwards, this data is processed and compared with the two more complex numerical models of the hierarchy in a process of analysis and calibration of these models. From this analysis, it is possible to show the representativeness of the developed models and the relationship between model complexity, number of parameters and convergence.

[pt] Nos últimos anos tem-se observado o crescente fomento de pesquisas globais por sistemas de energias renováveis que proporcionem menor impacto ambiental, garantindo às necessidades do presente sem comprometer a capacidade das gerações futuras. Tal propósito tem impulsionado o avanço da pesquisa em diferentes áreas do campo da energia eólica global, objetivando-se entender o comportamento estrutural e mecânico de cada componente, a fim de garantir uma engenharia de maior segurança e qualidade, bem como reduzir o tempo de indisponibilidade dos aerogeradores. O presente estudo tem como objetivo avaliar o comportamento estrutural de um aerogerador onshore de eixo horizontal, com rotor de três pás, submetido a campos normais e extremos de velocidade do vento definidos de acordo com a IEC 61400- 1 - Wind Turbines Design Requirements. Devido ao acesso limitado às informações técnicas dos aerogeradores comercializados pelos fabricantes, será realizada a análise para o aerogerador de referência de 5 MW desenvolvido pelo Laboratório Nacional de Energias Renováveis (NREL) dos Estados Unidos, o qual disponibilizou as especificações técnicas do aerogerador para acesso público. O comportamento da estrutura será avaliado através da simulação do sistema acoplado rotor-torre-fundação no código FAST, que é um simulador aero-hidro-servo-elástico desenvolvido pelo NREL, o qual está abertamente disponível e bem documentado no meio científico. Os casos de vento normal e extremo, estabelecidos pela IEC 61400-1 e utilizados no FAST, são processados pelo programa TurbSim, também disponibilizado pelo NREL. A análise modal do aerogerador é realizada pelo software SAP2000 para obtenção das frequências naturais e avaliação da característica dos modos de vibração da estrutura. O modelo de elementos finitos considera a torre e as pás discretizadas em elementos de viga. / [en] In recent years there has been a global research for forms of renewable energy which could provide less environmental impact as well as guarantee energy for future generations. This scenario leads to the rise of studies in wind power field which scrutinizes the wind turbine aiming to understand the structural and mechanical behaviour of each component in order to assure safer and quality engineering as well as reducing the wind turbines downtime. The present study aims to understand the structural behavior of an onshore three-bladed horizontal-axis wind turbine subjected to the normal and extreme wind speed fields defined in accordance with IEC 61400- 1 - Wind Turbines Design Requirements. Due to limited access to technical information on wind turbines marketed by manufacturers, the analysis will be performed for the 5 MW Reference Wind Turbine developed by the National Renewable Energy Laboratory (NREL) of the United States, which made the technical specifications of the turbine available for public access. The behavior of the structure will be evaluated through the simulation of the rotor-tower-foundation coupled system in the FAST code, which is an aero-hydro-servo-elastic simulator developed by NREL, which is openly available and well documented in the scientific community. The cases of normal and extreme wind, established by IEC 61400-1, used in FAST, are processed by the TurbSim program also provided by NREL. The modal analysis of the wind turbine is performed using the software SAP2000 in order to obtain the natural frequencies and evaluate the characteristic of the structure s vibration modes. The finite element model considers the tower and the blades discretized into beam elements.

The Tubed Mega Frame (TMF) is a structural system for high-rise building developed by Tyréns AB. Compared to conventional structural systems, the TMF is a coreless system that transfers the loads through the perimeter of the building instead and in turn enables ability to support new architectural shapes and forms of buildings. This thesis covers an initial study of a high-rise building with an unconventional shape implementing the TMF system, the Cable-stayed Building, which consists of a slanted tower with a cable-supported cantilever. The study of the building was divided in to a geometrical study and a cable study. The geometrical study was carried out to gain an initial understanding of the global structural behavior by altering specific geometrical parameters. The cable efficiency in terms of total vertical forces was investigated in the cable study by comparing different cable arrangements, cable diameters and prestressing forces for a fixed global geometry. The studies were performed under linear and nonlinear static conditions using the finite element software SAP2000 and ETABS. The results from the geometrical study showed that the cable efficiency increases in terms of larger vertical cable forces with a less inclined building and longer cantilever length. In addition, the results showed significant effects of geometric nonlinearities considering P-delta for different geometric cases. Furthermore, a study of the axial forces in the mega columns indicated that the most inclined building in which no uplifting forces and barely any tension occur along the mega columns, is the 7° incline with cantilever length 73.4 m. As abovementioned, the efficiency of the cables was compared for different arrangements, cable diameter and prestressing forces. The results indicated that as the prestressing force increases, the efficiency of cables rises more for smaller cable diameter than for larger. Furthermore, the comparison of fan- and harp-shape cable arrangements showed that the latter, including three pairs of cables, gives the highest cable efficiency relative to the amount of steel required of the cantilever bracing system. Nevertheless, the study indicates that the cable forces are inherently dependent on many parameters, such as the sag effect considered in the modulus of elasticity and the stress inducing temperature, which in turn depends on cable diameter, prestressing force and cable arrangement. To conclude the study, a modal analysis showed that the Cable-stayed Building is classified as a stiff building according to the guidelines from Council on Tall Buildings and Urban Habitat. Further research on the structure could be carried out within different areas, as this thesis is only an initial study of the structure. For instance, material nonlinearities, dynamic responses of the building as well as soil structure interaction, should be investigated further. / Tubed Mega Frame (TMF) är ett bärande system för höghus utvecklat av Tyréns AB. TMF är, till skillnad från nuvarande konstruktioner, ett system utan en bärande kärna som överför laster via byggnadens perimeter istället, vilket skapar nya förutsättningar gällande arkitektoniska former på höghus. I detta projektarbete genomförs en förstudie på en byggnad med en ovanlig design, Snedkabel Byggnaden, bestående av ett lutande torn och en konsol som bärs upp av kablar.  Studien är uppdelad i en geometrisk analys och en kabel analys. Den geometriska studien syftar till att få en uppfattning om hur det globala bärande systemet beter sig genom att variera vissa geometriska parametrar. Syftet med kabel studiens är att undersöka kablarnas effektivitet genom att jämföra den totala vertikala kabelkraften med olika kabelsystem, kabeldiametrar och förspänningar för en fastställd geometri av byggnaden. Statiskt linjära och ickelinjära strukturanalyser genomfördes för båda studier i finita element programmen SAP2000 och ETABS. Resultaten från den geometriska studien visade att kabel effektiviteten ökar för en mindre lutad byggnad och en längre konsol, då kabelkrafterna ökar. Dessutom indikerar resultaten anmärkningsvärda effekter vid beaktandet av ickelinjäritet med P-delta för olika globala geometrier. En undersökning av axialkrafter i pelarna visar att den mest lutade byggnaden som inte ger upphov till upplyftande krafter och knappt några dragkrafter längs pelarna är byggnaden med 7° lutning och konsollängd på 73.4 m.   Som tidigare nämnt undersöktes kablarna effektivitet genom att jämföra olika kabelsystem, kabeldiametrar och förspänningar. Resultaten påvisade att med högre förspänningar, desto mer ökar kabeleffektiviteten för mindre kabeldiameter än större. Dessutom visade jämförelsen mellan solfjäder- och harp-systemet att harp-systemet med tre kabelpar ger stört kabeleffektivitet i relation till stålmassan för stagningen i konsolen. Krafterna i kablarna beror i sig till stor del av exempelvis elasticitets modulen med hänsyn till kablarnas nedböjning och den spänningsinducerande temperaturen, som i sin tur beror på kabeldiameter, förspänning och kabelsystem. Avslutningsvis utfördes en modalanalys som visade på att Snedkabel Byggnaden klassificeras som en styv byggnad enligt riktlinjer från Council on Tall Buildings and Urban Habitat. Ytterligare studier på strukturen kan genomföras inom olika områden, då detta är en förstudie på byggnaden. Exempelvis på vidare forskning är att ta hänsyn till materialens ickelinjäriteter, byggnadens dynamiska respons samt samverkan mellan byggnad och grund.

No description available.

El trabajo de investigación tiene como objetivo principal: determinar la influencia de la configuración estructural de los elementos de soporte (columnas y placas) del sistema aporticado y del sistema dual en el diseño de la cimentación de un edificio de 4 pisos de uso comercio, ubicado en el distrito de Huancayo, sobre un suelo arcilloso con capacidad portante de 1.27 kg/cm2. A partir del plano de arquitectura se plantearon tres configuraciones estructurales para los soportes: una para el sistema aporticado, una para el sistema dual tipo I y una para el sistema dual tipo II. Se continuó con el análisis estructural para cargas de gravedad y sismo, utilizando el programa SAP2000 V19, para así obtener las fuerzas y momentos de diseño de cada elemento de soporte. Tomando en cuenta la norma E.060 capítulo 21, se diseñaron las columnas y placas. Luego se plantearon las alternativas de cimentación para cada configuración que satisfaga adecuadamente la transmisión de cargas axiales y momentos flectores de las columnas y placas al suelo, eligiendo las más óptimas para realizar su diseño y un comparativo en cuanto a costos de cimentación tomando en cuenta las partidas más representativas de: concreto, acero y encofrado, seleccionando así el tipo de cimentación más económica para cada configuración estructural. Finalmente se realizó un comparativo entre las tres configuraciones estructurales evaluando los criterios de desplazamientos, cimentación y metrados, para así obtener que estructura cumple mejor con los requisitos de seguridad, economía y durabilidad.

The objective of this study is to investigate the accuracy and computational efficiency of two commonly used formulations for performing the geometrically nonlinear thermal analysis of plane framed structures. The formulations considered are the followings: the Beam-Column formulation and the updated Lagrangian version of the finite element formulation that has been adopted in the commercially well-known software SAP2000. These two formulations are used to generate extensive numerical data for three plane frame configurations, which are then compared to evaluate the performance of the two formulations. The Beam-Column method is based on an Eulerian formulation that incorporates the effects of large joint displacements. In addition, local member force-deformation relationships are based on the Beam-Column approach that includes the axial strain, flexural bowing, and thermal strain. The other formulation, the SAP2000, is based on the updated Lagrangian finite element formulation. The results for nonlinear thermal responses were generated for three plane structures by these formulations. Then, the data were compared for accuracy of deflection responses and for computational efficiency of the Newton-Raphson iteration cycles required for the thermal analysis. The results of this study indicate that the Beam-Column method is quite efficient and powerful for the thermal analysis of plane frames since the method is based on the exact solution of the differential equations. In comparison to the SAP2000 software, the Beam-Column method requires fewer iteration cycles and fewer elements per natural member, even when the structures are subjected to significant curvature effects and to restrained support conditions. The accuracy of the SAP2000 generally depends on the number of steps and/or the number of elements per natural member (especially four or more elements per member may be needed when structure member encounters a significant curvature effect). Succinctly, the Beam-Column formulation requires considerably fewer elements per member, fewer iteration cycles, and less time for thermal analysis than the SAP2000 when the structures are subjected to significant bending effects.

No description available.

The stress ribbon system has numerous advantages, that includes but are not limitedto: increasing overall stiffness, control deflections and reduction of materialsconsumption, which in turn, reduces the load and the cost. Nevertheless, its use isusually limited to bridges, in particular, pedestrian bridges; this can be attributedto the insufficient space that buildings’ usually have for end supports, or/and backstayedcables, that can accommodate the expected high pull-out forces occuring atthe cables’ ends. In this work, the roof of Västerås Travel Center, which will become one of the longestcable suspended roofs in the world, was chosen as a case study. The aim was toinvestigate the optimal technique to model the post-tensioned stress ribbon systemfor the roof structure using SAP2000, and to assess any possible reduction in thepull-out forces, deflections and concrete stresses. Subsequently, a conventional cablesuspended roof was simulated, using SAP2000, and compared to the post-tensionstress ribbon system in order to examine the potential of the latter. Moreover,the effects of temperature loads and support movements on the final design loadswere examined. Based on the study, a few practical recommendations concerningthe construction method and the iterative design process, required to meet thearchitectural geometrical demands, are stated by the authors. The results showed that the post-tensioned stress ribbon system reduces the concretestresses, overall deflections, and more importantly, reduces the pull-out forces by upto 16%, which substantially reduces the design forces for the support structures.The magnitude of these reductions was found to be highly correlated to the appliedprestressing force, making the size of the prestressing force a key factor in the design. / Konstruktioner med spännbandsystem bestående av bärande huvudkablar medpålagda plattor, ofta av betong, har många fördelar. Dessa fördelar inkluderarmen begränsas inte till ökad totalt styvhet, kontrollerade nedböjningar och reduceradmaterialförbrukning, vilket minskar lasten och kostnaden. Deras användningär dock vanligen begränsad till broar, särskilt gång- och cykelbroar, där det finnsutrymme för att förankra de höga utdragskrafterna från huvudkablarna. Motsvarandeutrymme finns sällan i byggnader. I det föreliggande arbetet har taket till Västerås Resecentrum valts ut som studieobjekt.Taket kommer att bli ett av väldens längsta kabelburna takkonstruktion.Syftet är att undersöka den optimala tekniken för att modellera ett efterspänt spännbandsystemför taket med hjälp av FE-programmet SAP2000 och att bedöma eventuellaminskningar på utdragskrafter, nedböjningar och betongspänningar. Däreftermodellerades en konventionell kabelburen takkonstruktion med SAP2000, och detjämfördes med det efterspända spännbandsystemet för att undersöka fördelarna avdet sistnämnda. Dessutom har effekten av temperaturlasten och upplagsrörelserundersökts på den slutliga modellen. Slutligen ges några praktiska rekommendationerom byggteknik och en iterativ dimensioneringsprocess som är nödvändig förarkitekturgestaltning och dess krav på geometri. Resultaten visar att det efterspända spännbandsystemet gav lägre betongspänningar,mindre totaltnedböjning, och ännu viktigare, mindre utdragskrafter. Krafterna minskade16%, vilket gav en minskning av konstruktionens horisontella upplagsreaktion.Storleken på reduktionen var direkt proportionell mot spännkraften, så förspänningär en nyckelfaktor vid dimensioneringen.