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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

Návrh mostní konstrukce v Blansku / Design of the bridge in the town Blansko

Poukar, Kryštof January 2016 (has links)
This diploma thesis deals with the proposal of a single box girder bridge of three spans in the town Blansko. It bridges the river Svitava and the main railway Praha - Brno. The calculations were carried out by hand, the model was created in the Scia Engineer programme. The thesis also describes the solving of a complicated phased construction with the necessity of turning the bridge into the final position. The construction is considered by Eurocodes.
92

Předpjatý pás přes hluboké údolí / Stress ribbon bridge across the deep valley

Tomisová, Gabriela January 2017 (has links)
The topic of this thesis is a design of stress ribbon bridge across the deep valley. The construction of the footbridge contains stress ribbon bridge with external cables and final prestressing tendons. The bridge deck is in a parabolic arc and the suspension cables are in two bend down parabolic arcs. The construction is reproduced for evaluation of longitudinal direction in the Ansys 14.0 programme and for transversal direction in the Scia Engineer 15.1 programme. The model was solved in several phases, nonlinerally. The pier was reproduced in the Scia Engineer 15.1 programme for local effect of action. The construction was evaluated for dynamic action. The construction is assessed according to the actual EN standards.
93

Polyfunkční dům / Multifunctional building

Vecheta, Jan January 2022 (has links)
The assignment of the diploma thesis is the elaboration of project documentation for the construction. It is a detached multifunctional house, which is located on a slightly sloping terrain. The building consists of four floors and is partially basement. In the basement of the building there are mainly storage spaces, which are designed for housing units located on the highest floors. The space of the first two floors consists mainly of commerce and there is a sports shop, massage equipment, hairdresser and office space. The building is based on simple concrete foundation strips. The perimeter masonry of the basement is made up of concrete blocks, which create lost formwork for concrete filling. The load-bearing masonry of the building consists mainly of ceramic blocks. The ceiling structures are made of Spiroll panels, which are complemented by reinforced concrete monolithic slabs. The building is insulated with the Etics contact insulation system. The roof is designed as a single-skin vegetation roof.
94

Statické řešení parkovacího domu / Static solution of parking house

Tvrzník, Jakub Unknown Date (has links)
The diploma thesis is focused on the design of the supporting structure of a multi-storey parking house. Part of the work is also a search of three parking houses in our country and in Slovakia. The content of the work is a preliminary design of 3 variants of a typical ceiling structure. Subsequently, one variant is selected and processed in detail. A flexurally supported slab-wall model was created in Scia Engineer for the analysis of the structure. Selected structural elements were modeled separately. Additional assessment is performed in GEO, FINE, IDEA Statica, JORDAHL and MS Excel software.
95

Mateřská škola v Příboře / Kindergarten in Příbor

Murgašová, Dominika Unknown Date (has links)
The subject of this master’s thesis is a project documentation for development of a nursery school. The nursery school is situated on the outskirts of the city Příbor. The school is designed as a two-storey building and includes 4 classrooms, with total capacity reaching 60 pupils. The perimeter wall consists of Porotherm clay block walling system. The ceiling framework uses a combination of two systems; the prestress hollow core slabs Spiroll and reinforced concrete monolithic blocks. The roof is designed as a single skin cladding with a flat, green roof. The external thermal insulation composite system (Etics) is proposed for the insulation of the building. The outer walls are partially cladded with timber. Additionally, the combination of white rendering and timber cladding will form a modern looking building that fits within a new housing development. Furthermore, the plan includes an outside playground, with allotments and parking spaces on the premises for the use of a nursery school.
96

Analysis of post-tensioned concrete box-girder bridges : A comparison of Incremental launching and Movable scaffolding system

El Hamad, Hamad, Tanhan, Furkan January 2018 (has links)
When designing a bridge it is of high importance that the geometry for the cross section is optimized for the structure. This is partly due to the influence of the amount of material needed and its impact on the budget and environment. The influence of choosing the right amount of each material lies in the unit-price of the different material, where they can differ significantly. The Swedish Transport Administration, Trafikverket, has ordered the construction of Stockholm Bypass which is one of Swedens largest infrastructure project and is valued to 27.6 billion SEK according to the price index of the year 2009. The infrastructure project is divided into multiple projects where one of them is assigned to Implenia and Veidekke through a joint venture (Joint venture Hjulsta, JVH) and is valued to nearly 800 MSEK. The reference bridge that is used in the analysis of the master’s thesis is a part of the project. The aim of this masters thesis was to analyze and compare the two construction methods, mov- able scaffolding system (MSS) and incremental launching for the reference bridge with respect to amount post-tensioning and slenderness. Furthermore, an economical comparison between the two construction methods was carried out based on the obtained results. The analysis of the MSS was carried out by modeling the reference bridge structure in the finite element software SOFiSTiK AG. The bridge was modeled with different cross section height, i.e. different slenderness where the optimal amount of post-tension tendons could be determined by iteration until stress conditions from the Eurocode were fulfilled. For the incremental launching method, a numerical analysis was performed. The optimal amount of required post-tensioning was evaluated in the construction stages and final stages with different construction heights i.e. different values of slenderness. A cost analysis was also performed where the aim was to analyze how the total cost of the construc- tion of the bridge would be influenced by the different slenderness of the bridge as a comparison for the two construction methods. This was done by dividing the costs into fixed costs and variable costs. The results showed that the structural rigidity had a large influence on the required amount of prestressing steel for both construction methods. In other words, the smaller the cross section the more prestressing steel was required. Incremental launching proved to require a much greater amount of (PT) tendons compared to the MSS although the identical cross sections and properties for both methods, except for the PT. The prestressing for incremental launching is generally by centrical prestressing during the construction stages. A intersection point was obtained in the cost analysis for the construction methods. The incremental launching was the cheaper solution for slenderness smaller than the intersection point at slenderness between 17 and 18. The MSS was cheaper than the incremental launching for slenderness larger than the intersection point. / Vid dimensionering av tvärsektioner i broar är det av stor vikt att optimera geometrin avseende materialåtgång då mängden material har stor på verkan på ett projekts budget samt miljö. Eftersom konstruktioner ofta består av olika byggnadsmaterial gäller det vid optimering att välja byggnadsmaterialen genom optimerad proportionalitet. Förbifart Stockholm, beställt av Trafikverket, är ett av Sveriges största infrastrukturprojekt och värderas till 27,6 miljarder kronor enligt 2009 års prisnivå. Infrastrukturprojektet är uppdelat i flera mindre entreprenader eller så kallade etapper. Den entreprenad som omfattar trafikplats Hjulsta Södra har blivit tilldelat till Implenia och Veidekke genom ett konsortium (Jointventure Hjulsta, JVH) och värderas till cirka 800 miljoner kronor. Den förspända betongbro som byggs i trafikplats Hjulsta ligger till grund för analysen i detta examensarbete och har använts som referens under vår studie. Syftet med examensarbete var att analysera och jämföra två de två olika produktionsmetoderna, Movable scaffolding system (MSS) och etappvis lansering med hänsyn till erforderlig mängd förspänningskablar och slankhet. Vidare, baserat på erhållna resultat, utfördes en ekonomisk analys och jämförelse mellan produktionsmetoderna. Analysen av MSS utfördes genom att modellera brokonstruktionen i mjukvaruprogrammet SOFiSTiK AG som bygger på finita elementmetoder. Konstruktionen modellerades för olika slankheter, där slankheten definieras som kvoten mellan maximala spannlängden och brons tvärsnittshöjd. Spannlängden hölls konstant medan tvärsnittshöjden varierade för att erhålla olika slankheter. Den optimala slankheten bestämdes genom iterering av mängd förspänningskablar tills spänningsvillkoren var uppfyllda enligt Eurocode. För analysen av etappvis lansering utfördes en numerisk analys vars den optimala mängden förspänningskablar utvärderades i byggskedet (construction stages) samt i slutskedet (final stage). Analysen utfördes på samma sätt för de olika slankheterna. Slutligen genomfördes en konstandsanalys för de olika metoderna. Syftet var att jämföra hur den totala kostnaden för uppförandet av brokonstruktionen skiljde sig för de olika slankheterna. Jämförelsen genomfördes genom att dela upp de olika kostnaderna i fasta kostnader samt rörliga kostnader. Resultaten från analysen visade att den erforderliga mängd förspänningskablar som behövs i en förspänd betongbro är beroende av den strukturella styvheten i tvärsektionen. En högre slankhet, alltså lägre tvärsnittshöjd, ger lägre styvhet och därav mer erforderlig förspänningskablar. Etappvis lansering visade sig vara den metod som krävde mer mängd förspänningskablar. I resultaten för kostnadsanalysen uppmättes en skärningspunkt, för en slankhet mellan 17-18, mellan de två olika metoderna. För förspända betongbroar med slankhet lägre än skärningsupunkten vid 17-18 är etappvis lansering det billigare alternativet. För slankheter högre än 17-18 är MSS det mer ekonomiskt lönsamma alternativet.
97

Kinematically singular pre-stressed mechanisms as new semi-active variable stiffness springs for vibration isolation

Azadi Sohi, Mojtaba 11 1900 (has links)
Researchers have offered a variety of solutions for overcoming the old and challenging problem of undesired vibrations. The optimum vibration-control solution that can be a passive, semi-active or active solution, is chosen based on the desired level of vibration-control, the budget and the nature of the vibration source. Mechanical vibration-control systems, which work based on variable stiffness control, are categorized as semi-active solutions. They are advantageous for applications with multiple excitation frequencies, such as seismic applications. The available mechanical variable stiffness systems that are used for vibration-control, however, are slow and usually big, and their slowness and size have limited their application. A new semi-active variable stiffness solution is introduced and developed in this thesis to address these challenges by providing a faster vibration-control system with a feasible size. The new solution proposed in this thesis is a semi-active variable stiffness mount/isolator called the antagonistic Variable Stiffness Mount (VSM), which uses a variable stiffness spring called the Antagonistic Variable stiffness Spring (AVS). The AVS is a kinematically singular prestressable mechanism. Its stiffness can be changed by controlling the prestress of the mechanisms links. The AVS provides additional stiffness for a VSM when such stiffness is needed and remains inactive when it is not needed. The damping of the VSM is constant and an additional constant stiffness in the VSM supports the deadweight. Two cable-mechanisms - kinematically singular cable-driven mechanisms and Prism Tensegrities - are developed as AVSs in this thesis. Their optimal configurations are identified and a general formulation for their prestress stiffness is provided by using the notion of infinitesimal mechanism. The feasibility and practicality of the AVS and VSM are demonstrated through a case study of a typical engine mount by simulation of the mathematical models and by extensive experimental analysis. A VSM with an adjustable design, a piezo-actuation mechanism and a simple on-off controller is fabricated and tested for performance evaluation. The performance is measured based on four criteria: (1) how much the VSM controls the displacement near the resonance, (2) how well the VSM isolates the vibration at high frequencies, (3) how well the VSM controls the motion caused by shock, and (4) how fast the VSM reacts to control the vibration. For this evaluation, first the stiffness of the VSM was characterized through static and dynamic tests. Then performance of the VSM was evaluated and compared with an equivalent passive mount in two main areas of transmissibility and shock absorption. The response time of the VSM is also measured in a realistic scenario.
98

Kinematically singular pre-stressed mechanisms as new semi-active variable stiffness springs for vibration isolation

Azadi Sohi, Mojtaba Unknown Date
No description available.
99

Statické posouzení stávajícího železobetonového skeletu výrobního objektu / Structural assessment of the existing reinforced-concrete frame structure of the production building

Pražan, Jiří January 2019 (has links)
The diploma thesis deals with the structural assessment of the existing reinforced concrete frame structure of the production building. The structure under consideration is carried out as a reinforced concrete monolithic frame structure with a discrepancy of 6,15 x 6,15 m (axis). The object has a rectangular plan of 13 x 9 fields. The total dimension is 56 x 81m and is divided into three dilation units on all floors by two inserted 3,65 m wide fields. The building has three above-ground floors and one underground floor. The construction height of the basement is 3,675 m, above ground level 4,0 m. On the west side of the building (axis A) are three reinforced concrete elevator shafts with a dimension of approximately 4,5 x 3,8 m. The envelope and inner partitions are made of bricks full of burned. The work shall include a static assessment of the status quo, a determination of the load capacity and a proposal for appropriate adjustments to ensure static reliability.
100

Návrh kruhové betonové nádrže / Design of the circle concrete tank

Šimek, Ondřej January 2019 (has links)
The diploma‘s thesis deals with the design and assessment of prestressed cocrete tank of biogas station at ultimate limit state and also at serviceability limit state, according to ČSN EN 1992-1-1: Design of concrete structures. Specifically, the design of wall of the tank and foundation slab. The text part contains general information on the desing of the structure, static idealization of the structure, type of load and method for calculation of inner forces. Attachments contain drawing documentation and structural analysis, which completes the text part and solves in detail said structure.

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