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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.
101

Dimensionamento à punção em apoios internos de lajes protendidas sem aderência

Leite Júnior, José Carlos Cirino 14 August 2015 (has links)
Submitted by Morgana Andrade (morgana.andrade@ufes.br) on 2016-03-22T19:49:43Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) jose carlos cirino leite junior.pdf: 4435177 bytes, checksum: 8e8f6eb9e0f91d4f07653b556647e567 (MD5) / Approved for entry into archive by Patricia Barros (patricia.barros@ufes.br) on 2016-03-23T15:31:40Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) jose carlos cirino leite junior.pdf: 4435177 bytes, checksum: 8e8f6eb9e0f91d4f07653b556647e567 (MD5) / Made available in DSpace on 2016-03-23T15:31:40Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) jose carlos cirino leite junior.pdf: 4435177 bytes, checksum: 8e8f6eb9e0f91d4f07653b556647e567 (MD5) / Esta dissertação trata da punção em lajes protendidas com cordoalhas não aderentes, para pilares internos, calculadas através das normas ABNT NBR 6118:2007, ABNT NBR 6118:2014, EN 1992-1-1:2004 e ACI 318-11. Ao longo do trabalho, são apresentados dimensionamentos à punção através desses códigos a fim de se obter uma análise comparativa dos resultados. Além disso, são expostas três situações de provas de carga não destrutivas para punção, realizadas em lajes reais. Os casos, verificados a partir da comparação entre as quatro normas, servem de base para avaliações sobre o nível de segurança estrutural entre os dimensionamentos. Após as análises teóricas, conclui-se que, no geral, o EC2:2004 e a NBR 6118:2014 são os códigos que geram os resultados menos conservadores no cálculo das armaduras de punção. Já o ACI 318-11 e a NBR 6118:2007 obtêm os resultados mais conservadores para esse dimensionamento. Quando considerados os carregamentos máximos sem utilização de armadura de punção, a norma americana se destaca, obtendo valores comparáveis aos do EC2:2004 e da NBR 6118:2014. A NBR 6118:2007 resulta em dimensionamentos sempre mais conservadores. / This work studies the punching shear in prestressed slabs with unbonded tendons, for internal columns, calculated by ABNT NBR 6118:2007, ABNT NBR 6118:2014, EN 1992-1-1:2004 and ACI 318-11. Punching shear calculations will be presented in order to obtain comparative results analysis. Also, there are three situations presented of non-destructive load tests for punching shear, in real slabs. The cases, calculated using the four compared regulation codes, provide a basis for assessments of the conservatism level among the formulations. After the theoretical analysis, in general, it is concluded that EC2:2004 and NBR 6118:2014 are the codes that generate less conservative results in punching shear calculation. However, ACI 318-11 and the NBR 6118:2007 obtain the most conservative results for this design. Considering the maximum loads without the use of punching shear reinforcement ACI 318 generates values comparable to EC2 and NBR 6118:2014. The most conservative results are always generated by NBR 6118:2007.
102

Punção em lajes cogumelo : estudo da retangularidade dos pilares

MOURO, Valéria Conceição 31 August 2006 (has links)
Made available in DSpace on 2014-07-29T15:03:37Z (GMT). No. of bitstreams: 1 Dissertacao Christine Garrido Marquez.pdf: 3277601 bytes, checksum: e27c6b29c8e0951b47d16d9bbfeb2287 (MD5) Previous issue date: 2006-08-31 / Eight reinforced concrete square flat slabs of reinforced concrete were tested. Slabs were 130mm thick with an 1800 mm side and were submitted to central loading, and the objective was to investigate the influence of column rectangularity coefficient. Column cross section dimensions (cmáx/cmín) varyied between 1 and 4, with a constant perimeter equal to 1000mm. Results presented and analysed include ultimate loads and failure types, modes of rupture, vertical displacements, cracking and deformations of steel and concrete. Comparisons with codes, norms and results of literature results are also presented. The results indicate that as the rectangularity coefficient increases, punching shear resistance decreases for constant perimeter column flat slabs. Suggesting that punching shear has to be considered specially in regions close to column extremity, where there is a larger concentration of shear forces. A proposal for an inclusion of the retangularity parameter (cmáx/cmín) in expressions for calculation punching shear resistance of ACI (2002), CEB-FIP (1991), EC2 (2001) and NBR-6118 (2003) codes is presented. / São analisadas experimentalmente 8 (oito) lajes cogumelo de concreto armado quadradas com 1800 mm de lado e 130 mm de espessura, submetidas a carregamento central, com o objetivo de investigar a influência do índice de retanguralidade do pilar, sendo que a relação entre as dimensões da seção transversal do pilar (cmáx/cmín) variou entre 1 e 4, com perímetro mantido constante e igual a 1000 mm. São apresentados e analisados os resultados das cargas últimas, modos de ruptura, deslocamentos verticais, fissuração e deformações do aço e concreto. São apresentadas comparações dos resultados experimentais com códigos, normas de projeto e resultados da literatura. Os resultados indicam que à medida que aumenta o índice de retangularidade, a resistência à punção diminui, para lajes que possuem pilares com o perímetro constante. Sugerindo que o combate à punção pode ser mais efetivo em regiões próximas das extremidades dos pilares, onde há maior concentração de forças cortantes. É apresentada uma proposta de inclusão do parâmetro cmáx/cmín nas expressões de cálculo da resistência à punção do ACI (2002), CEB-FIP (1991), EC2 (2001) e NBR-6118 (2003).
103

Most přes řeku Jevišovku / Bridge over the Jevišovka river

Čípek, Luboš January 2019 (has links)
This thesis focuses on design and assessment of load-bearing construction of a bridge over Jevišovka river at road I/53 near Lechovice. The bridge was designed as a trapezoidal cross-section slab. This solution was chosen from three sketch eventualities. The work includes an implementing engineering report, construction process report and report about static-analysis, the attachments include the sketch, vizualization, drawings, component drawing, construction process and the static-analysis of this structure. Computing of internal forces was performed by computational software Scia Engineer 17.
104

Polyfunkční dům / Multifunctional Building

Kika, Aleš January 2015 (has links)
The project deals the part of the structure of multifunctional building . It is a multi-storey building. In this project are designed slab, basement wall, continous footing, column and footing . Static system and the calculations of the internal forces was conducted in a student version of Scia Engineer 2012.
105

Nosná konstrukce nemocničního pavilonu / Load-bearing Structure of Hospital Pavilion

Hůrka, Jiří January 2015 (has links)
The thesis is focused on the design and assessment of selected elements of load-bearing structure of hospital pavilion. This pavilion consisted of board frame with additionally lined self-supporting perimeter cover. Selected elements of the structure are locally supported slab, columns, foundation pad and staircase . Computational model was assembled of the software RFEM5. Internal forces locally supported slab were verified by manual calculation. The design documentation consist of engineering report, structural analysis and shape and reinforcements drawings of selected structural elements.
106

Dvorní vícepodlažní přístavba výukových prostor / Court multi-storey outbuilding university space

Rochová, Lucie January 2016 (has links)
The topic of the diploma thesis is the design of monolithic concrete structure CERIT in Brno. There are designed three preliminary variants of the concrete structure for the problematic place in the building. Selected variant is developed in detail design (the concrete wall). The solution comprises statical analysis, text section and drawing documentation.
107

Non-Linear Assessment of a Concrete Bridge Slab Loaded to Failure / Icke-linjär analys av ett betongbrodäck belastat till brott

Isabell, Eriksson, Karlsson, Niklas January 2016 (has links)
This thesis covers an investigation regarding the failure in the bridge slab of Gruvvägsbron, which was the result of the full scale test that the bridge was subjected to prior to demolition. Using the non-linear finite element software ATENA 3D, a model of the bridge was assembled, with the purpose to attempt to reenact the test procedure and realistically capture the failure load and behaviour. This in order to be able to conclude what kind of failure that occurred. The initial part of this thesis presents a summary of a conducted literature study, which aims to give deeper knowledge regarding the linear shear and punching shear phenomena and their respective failure mechanisms, and how they are applied on bridge slabs. Furthermore, the shear capacity of the bridge was calculated according to current design codes. A parameter study was conducted on the model, which initially showed a over-stiff response. The aim of this was to study the influence of key variables on the outcome of the analysis, and hopefully get closer to the failure load acquired inthe experiment. From the studied parameters, it was observed that a combined reduction of the tensile strength and fracture energy, together with a low fixed crack coefficient had the largest influence on the outcome of the analysis. It was also observed that the location of the failure and failing load was dependant on how the loading was applied to the model, i.e. via load control or deformation control. The final model failed at a load which surpassed the actual failure load by 10.5%. The mode of failure obtained in all the analyses were the result of a large shear crack propagating from the edges of the loading plate, through the slab to the slab/girder-intersection. This indicates that the type of failure that occurred was primarily due to a linear shear mechanism with a secondary punching effect. The design values calculated by keeping with the current codes resulted in too conservative values when compared to the obtained failure load from the experiment. This proves the difficulty in regarding the internal force distribution in slab struc-tures as well as the shear carrying width, which from the analysis were found to be larger than that obtained from the code. / Denna uppsats behandlar en utredning gällande brottet i plattan på Gruvvägsbron, som var resultatet av det fullskaletest som bron utsattes för innan rivning. Med hjälp av den icke-linjära finita element-programvaran ATENA 3D skapades en modell avbron, med syfte att på ett realistiskt sätt försöka återskapa experimentet och fånga brons verkliga beteende. Detta för att således kunna dra slutsatser angående brottets natur. Den första delen av denna uppsats innehåller en sammanfattning av en utförd litteraturstudie, som ämnar ge en ökad förståelse angående fenomenen skjuvning och genomstansning, tillsammans med olika brottmekanismer relaterade till dessa. Vidare har brons motstånd mot skjuv- och genomstansningbrott beräknats enligt rådande normer. En parameterstudie utfördes på modellen, då den ursprungligen uppvisade ett överstyvt beteende. Syftet med detta var att studera nyckelparametrars påverkan på analysens resultat, och eventuellt komma närmare den verkliga brottlasten i experimentet. Av de studerade parametrarna observerades att en samtida reduktion av draghållfasthet och brottenergi, samt ett lågt värde på den så kallade "fixedcrack"-koefficienten gav störst inverkan på resultatet. Vidare observerades att brottets lokalisering och brottlasten var beroende av hur lasten påfördes modellen, dvs genom last- eller deformationsstyrning. Den slutgiltiga modellen gick till brott vid en last som översteg den verkliga brottlasten med 10.5%. Brottet som skedde var i samtliga analyser resultatet av en skjuvspricka som sträckte sig från kanten av lastplattan, genom plattan, ner till mötet mellan platta och balk. Detta indikerar att den typ av brott som skedde var ett primärt skjuvbrott med en sekundär stanseffekt. Lastvärdena beräknade enligt rådande normer tycks vara för konservativa, om jämförelse görs med lasten som uppnåddes i experimentet. Detta visar på svårigheten i att bedöma den inre kraftspridningen i plattor, och även dess skjuvbärande bredd, då analysen visade att denna var betydligt större än vad som ges i koden.
108

Řešení vybraných detailů betonových konstrukcí vyztužených kompozitní výztuží / Design of selected details of concrete structures reinforced with composite reinforcement

Vašátko, David January 2022 (has links)
The aim of this master thesis is to explore and describe behavior of slab in punching shear. In total four concrete slabs were experimentally tested; each being reinforced differently. Using real experiments, there was a possibility to observe different behavior of steel and FRP reinforcement, eventually even the effect of adding FRP stirrups on load-bearing capacity. For the purpose of experimental testing design, currently placed formulas used to determine punching shear capacity were adjusted for application on longitudinal and shear FRP reinforcement. Atena software was used to approximate behavior of specimens by performing a nonlinear analysis. After the results of loading tests were obtained, next step was the comparison of design approaches and comparison of behavior of nonlinear model to a real specimen. In practical part, design of locally supported slab with requirement of non-magnetic reinforcement took place.
109

Návrh betonových konstrukcí vyztužených nekovovou FRP výztuží / Design of concrete structures reinforced with non-metallic FRP reinforcement

Golisová, Michaela Unknown Date (has links)
This diploma thesis investigates the design of concrete structures reinforced with non-metallic FRP reinforcement with a focus on solving the bearing capacity in extrusion. The work is divided into a theoretical and a practical part. The theoretical part begins with an introduction to FRP reinforcement and a description of shear stress. The following is an introduction to current approaches dealing with this issue. In the practical part, in connection with these regulations, parametric studies are developed to compare the influence of individual input parameters and selected regulations. The last part is dedicated to the design and nonlinear analysis performed in the ATENA software.
110

Multifunktionellt verktyg för bockning och stansning

Martinsson, Tua, Thunell, Hedda January 2023 (has links)
In general, bending and punching machines are large-scale equipment commonly used in factories or industries for mass production purposes. In this project, the opportunity to develop a smaller-scale multifunctional tool that can perform the same functions through manual force is investigated. This will be fulfilled by offering an alternative solution that combines both functionalities within a single tool. The aim is to design and construct a user-friendly multi-tool capable of bending and punching thin EN- AW 1050 H24 aluminum sheets using manual force. The research questions were answered through a combination of qualitative and quantitative research methods, including interviews, workshops, benchmarking, and FEM analysis. An iterative product development process was employed to establish a detailed specification for the multifunctional tool. Several concepts for the multifunctional tool were developed based on the defined specification, and the final concept was selected using a morphological matrix and concept screening. The tool was manufactured using cutting processes and additive manufacturing techniques. The resulting tool successfully achieved functionality for bending aluminum sheets up to 1.5 mm in thickness, enabling bends at 90° or 45° angles. Through the implementation of the project's methods and analyses, a finalized product meeting the majority of the specification requirements was produced, proving to be functional for bending. However, the punching functionality requires further development due to budget and scheduling constraints, which limited the attainable level of full functionality. To facilitate tool usage, an instruction manual was created, providing users with information on operation, maintenance, and the production of new tools. / Vanligtvis är bocknings- och stansningsmaskiner stora och används i verkstäder eller industrier för massproduktion. I detta projekt undersöks möjligheten att utveckla ett multifunktionellt verktyg i mindre skala för att utföra samma funktioner med hjälp av handkraft. Detta genom att erbjuda en alternativ lösning där de båda funktionerna är kombinerade i samma verktyg. Syftet är att utveckla och konstruera ett lättanvändligt multiverktyg för bockning och stansning av tunn aluminiumplåt EN-AW 1050 H24 med hjälp av handkraft. Frågeställningarna besvarades genom både kvalitativa- och kvantitativa forskningsmetoder genom bland annat intervjuer, workshops, benchmarking och FEM-analyser. Genom en iterativ produktutvecklingsprocess fastställdes en detaljerad kravspecifikation för det multifunktionella verktyget. Utifrån den definierade kravspecifikation utvecklades flera koncept för ett multifunktionellt verktyg där det slutgiltiga konceptet valdes med hjälp av morfologisk matris och konceptsållning. Verktyget framställdes med hjälp av skärande bearbetning samt additiv tillverkning. Det framställda verktyget var funktionellt för bockning av aluminiumplåtar upp till 1,5 mm tjocklek och möjliggjorde bockning till 90° eller 45°. Genom projektets metoder och analyser framställdes en färdig produkt som uppfyllde merparten av kravspecifikationen och är funktionell för bockning. Funktionen för stansning behöver däremot vidare utveckling då budget och tidsplan var en stor faktor som inte möjliggjorde full funktionalitet. För att underlätta användningen av verktyget skapades även ett instruktionsblad som tillhandahåller användaren med information om användning, underhåll och tillverkning av nya verktyg.

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