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Xu, Jun. "Dynamic thermal tensioning for welding induced distortion control /". Thesis, Connect to this title online; UW restricted, 2006. http://hdl.handle.net/1773/7145.
Pełny tekst źródłaNilimaa, Jonny. "Upgrading concrete bridges : post-tensioning for higher loads". Licentiate thesis, Luleå tekniska universitet, Byggkonstruktion och -produktion, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-25964.
Pełny tekst źródłaDet finns ett stort antal gamla konstruktioner runtom i världen och många byggdes för helt andra användningsområden än vad de numera används till. Som ett exempel kan nämnas att svenska järnvägsbroar i början av 1900-talet byggdes för att klara av att bära axellaster på maximalt 200 kN, medan några av våra nybyggda broar är konstruerade för dubbelt så stora axellaster. Även traffikmängden har mångdubblats och tåghastigheterna är nu högre än någonsin. Trågbroar i armerad betong är en typisk bro som byggdes i Sverige framförallt på 50-talet och den är fortfarande en av de vanligaste brotyperna i Sverige. Trågbroarna konstruerades normalt för att bära lägre laster än vad vi har idag och för att kunna ha kvar dessa broar när lasterna ökar kan det krävas någon form av uppgradering av bärförmågan. Det finns två sätt att förbättra bärförmågan på en gammal bro, nämligen administrativ uppgradering eller förstärkning. Administrativ uppgradering innebär att nya förbättrade beräkningsmetoder används tillsammans med verkliga materialhållfastheter, geometrier och laster för att mer noggrant räkna ut brons bärförmåga. Normalt visar det sig att bärförmågan är högre än vad de ursprungliga beräkningarna antydde. På så vis höjs kapaciteten med minimal fysisk åverkan på bron. Uppgradering genom förstärkning innebär däremot att konstruktionens bärförmåga höjs genom att förändra bron ur ett rent fysiskt perspektiv. Metoder för att öka böjkapaciteten på trågbroar i betong har utvecklats och testats tidigare, men förstärkningsmetoder för att höja tvärkraftskapaciteten saknas däremot fortfarande. Målet för denna avhandling ligger därför i att utveckla en förstärkningsmetod som kan användas för att förbättra tvärkraftskapaciteten för bottenplattan på trågbroar i betong. Det finns dock några svårigheter sammankopplade med förstärkning av befintliga järnvägsbroar, t.ex. tågtraffik under förstärkningsförfarandet och att viktiga betongytor är skyddade av ballast.Inga befintliga förstärkningsmetoder bedömdes däremot som lämpliga för det avsedda användningsområdet vid ”State-of-the-Art’’ studien. Invändig efterspänning av broplattan i tvärledd bedömdes som den bäst lämpade förstärkningsmetoden och efterföljande forskning fokuserades på att reda ut möjligheter för och förstärkningseffekter av efterspänning. Två olika laboratorieförsök genomfördes under forskningsprojektet och förstärkningsmetoden testades slutligen vid ett fältförsök på en 50 år gammal järnvägsbro i Haparanda.Själva tillvägagångssättet för förstärkningsmetoden består av fyra viktigaoch sammanhängande arbetssteg:1. Borrning av horisontella hål tvärs igenom trågbrons bottenplatta.2. Installation av själva försstärkningssystemet.3. Efterspänning av förstärkningssystemet.4. Förslutning av förstärkningssystemet.Både laboratorie och fältförsöken blev lyckade och resultaten visade att stålarmeringen inuti betongen trycktes ihop när trågbron efterspänndes. Tack vare denna kompression så kan broplattan bära högre laster innan dragarmeringen börjar flyta och bron slutligen går sönder. Med andra ord så höjdes brons böjkapacitet. Fältförsöket visade att de åtta spännstagen, efterspännda med 430 kN per stag, helt och hållet motverkade dragarmeringens påkänningar av ett tåg med axellasten 215 kN. Förstärkningsmetodens effekt på tvärkraftskapaciteten är däremot inte lika lätt att påvisa men laboratorieförsöken visade att töjningen reducerades betydligt i den uppbockade dragarmeringen, i zonen där plattan fäster i huvudbalkarna. De lägre töjningsnivåerna kan tolkas som lägre skjuvpåkänningar och efterspänningen kan därmed ha en positiv effekt på broplattans tvärkraftskapacitet. Laboratorieförsöken visade däremot att både Eurokod 2 och BBK är restriktiva när det gäller att uppskatta efterspänningens effekt på tvärkraftskapaciteten. En ny förstärkningsmetod för trågbroar i betong har därmed föreslagits i och med denna avhandling, men en del frågetecken kvarstår och i kapitel 8 ges därför förslag på fortsatta forskningsområden.
Godkänd; 2013; 20130107 (jonnil); LICENTIATSEMINARIUM Ämne: Konstruktionsteknik/Structural Enginering Examinator: Professor Björn Täljsten, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet Diskutant: Professor Mohammad Al-Emrani, Chalmers tekniska högskola, Göteborg Tid: Tisdag den 5 februari 2013 kl 13.00 Plats: F1031, Luleå tekniska universitet
Hutchison, Michael John. "Corrosion of Post-Tensioning Strands in Ungrouted Ducts - Unstressed Condition". Scholar Commons, 2013. http://scholarcommons.usf.edu/etd/4905.
Pełny tekst źródłaBruce, Trevor Louis. "Behavior of Post-Tensioning Systems Subjected to Inelastic Cyclic Loading". Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/49111.
Pełny tekst źródłaMaster of Science
Yang, Xiong. "Use of Fiber Reinforced Polymer Composite Cable for Post-tensioning Application". FIU Digital Commons, 2015. http://digitalcommons.fiu.edu/etd/2259.
Pełny tekst źródłaTofangchi, Mahyari Abbas-Ali. "Static and seismic rehabilitation of concrete gravity dams by post-tensioning". Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=26430.
Pełny tekst źródłaIn this study, the flood and seismic safety evaluations of prestressed dams were carried out using the gravity method, and linear and fracture finite element methods. Two typical concrete gravity dam models, 35 m and 90 m in heights, were examined. The performance of different post-tensioning modelling techniques such as the equivalent force method, and bonded/unbonded cable elements was examined in finite element analyses. A new nonlinear analysis methodology using displacement control was studied to determine the required amount of post-tensioning forces under flood condition. Sliding stability (local and global), overstressing, and controlled damage requirements were considered to develop post-tensioning design criteria in rehabilitation of concrete gravity dams. Various schemes of post-tensioning cable layouts were examined in seismic analyses.
The different prestressing modelling techniques present almost identical static and seismic structural behaviours. The material properties of the horizontal joint at the dam-foundation interface, and the tendon layouts were found the key prestressing design parameters. Linear finite element analyses predict higher required prestressing forces compared to other analysis methods. In general, flood resistant: design of prestressing also presents adequate seismic performance for small dams. However, additional partial prestressing is required near the downstream face of higher dams to prevent cracking at this location.
Mortazavi, A. A. "Behaviour of confined concrete columns with and without lateral pre-tensioning". Thesis, University of Sheffield, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.524999.
Pełny tekst źródłaLazzarini, Daniel Louis. "Seismic Performance of Unreinforced Masonry Walls Retrofitted with Post-Tensioning Tendons". DigitalCommons@CalPoly, 2009. https://digitalcommons.calpoly.edu/theses/143.
Pełny tekst źródłaKajewski, Stephen L. "Post-tensioning and its effect on multi-level formwork load distribution". Thesis, Queensland University of Technology, 1998. https://eprints.qut.edu.au/36033/8/36033_Digitised_Thesis.pdf.
Pełny tekst źródłaTaha, Mahmoud Reda. "A new non-metallic anchorage system for post-tensioning applications using CFRP tendons". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape3/PQDD_0022/NQ49541.pdf.
Pełny tekst źródłaRichards, David George. "Control of Residual Stresses in Welding A1-Aerospace Alloys by Machanical /Thermal Tensioning". Thesis, University of Manchester, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.518882.
Pełny tekst źródłaGeßner, Stephan [Verfasser], Josef [Akademischer Betreuer] Hegger i Joost [Akademischer Betreuer] Walraven. "Bond and anchorage of pre-tensioning tendons / Stephan Geßner ; Josef Hegger, Joost Walraven". Aachen : Universitätsbibliothek der RWTH Aachen, 2017. http://d-nb.info/1192375424/34.
Pełny tekst źródłaBowers, Susan Elizabeth. "Recommendations for Longitudinal Post-Tensioning in Full-Depth Precast Concrete Bridge Deck Panels". Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/32644.
Pełny tekst źródłaMaster of Science
O'Malley, Curtis John. "Experimental testing, analysis, and strengthening of reinforced concrete pier caps by exterior post tensioning". Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/41076.
Pełny tekst źródłaSuntharavadivel, Thuraichamy Guganesan. "Behaviour of shear damaged reinforced concrete beams strengthened with external post-tensioning and clamping". University of Southern Queensland, Faculty of Engineering and Surveying, 2008. http://eprints.usq.edu.au/archive/00006254/.
Pełny tekst źródłaRiad, Amr H. "Rehabilitation of HC-type bridge girders using CFRP-sheets/strips or external post-tensioning". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ38640.pdf.
Pełny tekst źródłaKam, Weng Yuen. "Selective Weakening and Post-Tensioning for the Seismic Retrofit of Non-Ductile RC Frames". Thesis, University of Canterbury. Department of Civil and Natural Resources Engineering, 2010. http://hdl.handle.net/10092/5237.
Pełny tekst źródłaPacheco, Alexandre Rodrigues. "Evaluating the corrosion protection of post-tensioning grouts : standardization of an accelerated corrosion test". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2003. http://hdl.handle.net/10183/170210.
Pełny tekst źródłaMusgrove, Ryan Ross. "Nondestructive detection of post-tensioning tendons and simulated voids in concrete specimens using thermal imaging". Online access for everyone, 2006. http://www.dissertations.wsu.edu/Thesis/Spring2006/r%5Fmusgrove%5F012506.pdf.
Pełny tekst źródłaPonton, Charles B. "Finite Element Analysis of Industrial Circular Sawblade With Respect to Tensioning, Rotating, Cutting, and Expansion Slots". Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/31279.
Pełny tekst źródłaMaster of Science
Nayal, Rim. "Post-tensioning the inverted-t bridge system for improved durability and increased span-to-depth ratio". Diss., Manhattan, Kan. : Kansas State University, 2006. http://hdl.handle.net/2097/240.
Pełny tekst źródłaSule, Jibrin. "Application of local mechanical tensioning and laser processing to improve structural integrity of multi-pass welds". Thesis, Cranfield University, 2015. http://dspace.lib.cranfield.ac.uk/handle/1826/9564.
Pełny tekst źródłaIcaza, Aguirre Juan José. "Factors affecting friction losses in multi-strand post-tensioning tendons including the effect of emulsifiable oils". Full-text Adobe Acrobat (PDF) file, 2004. http://www.engr.utexas.edu/research/fsel/FSEL_reports/Thesis/Aguirre,%20Juan%20Jose%20Icaza.pdf.
Pełny tekst źródłaKataria, Suresh. "Assessment of grouts for constructability and durability of post-tensioned bridges". [College Station, Tex. : Texas A&M University, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-2008-08-50.
Pełny tekst źródłaNewcombe, Michael Paul. "Seismic Design of Post-Tensioned Timber Frame and Wall Buildings". Thesis, University of Canterbury. Department of Civil and Natural Resources Engineering, 2011. http://hdl.handle.net/10092/6399.
Pełny tekst źródłaSullivan, Sean Robert. "Construction and Behavior of Precast Bridge Deck Panel Systems". Diss., Virginia Tech, 2007. http://hdl.handle.net/10919/27479.
Pełny tekst źródłaPh. D.
Zhang, Burong. "Experimental and theoretical investigations of a new bond-type anchorage system for post-tensioning applications with FRP tendons". Thèse, Université de Sherbrooke, 2001. http://savoirs.usherbrooke.ca/handle/11143/1732.
Pełny tekst źródłaMcAlpine, Patrick Charles. "Evaluation of the Effect of a Modified Wedge Geometry on the Behavior of Mono-Strand Post-Tensioning Anchorages". Thesis, Villanova University, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10185436.
Pełny tekst źródłaThe objective of this study is to create and evaluate if finite element modeling is a feasible approach to modeling different wedge geometries of post tensioned systems by comparing the experimental data from two wedges to analytical data. The motivation to develop an accurate finite element model of a wedge, tendon, and anchor system is to better understand the internal stresses the system is subjugated to and the interactions between components. By not fully understanding what is occurring within the anchor, the most efficient anchor cannot be designed. This can lead to premature failures of the strand which can result in total collapse of the structure. In recent years the applications of post tensioned strands have grown rapidly. Some of these applications require the strand to withstand higher strains than can currently be reached. An example of one of these applications is a shear rocking wall in earthquake prone areas. To date there is some experimental data on strand testing, but very little research has been conducted examining a modified geometry wedge. There is even less in depth literature on finite element modeling of the interactions between the components. One reason for this lack of research is because of the great variability in anchor and wedge configurations. Therefore, the focus of this research is to develop the interaction laws for one type of anchorage from one manufacturer. Once these laws are established and considered scientifically sound, the most efficient anchor wedge mechanism can be designed.
This thesis presents one of the stepping stone models needed to help converge on the interaction laws. The experimental component of this report evaluated two different wedge geometries. In the experimental trials the modified wedges preformed more efficiently than the standard wedges. The modified wedges were able to reach much higher strains. These geometries were modeled in a finite element program and the experimental results were replicated by adjusting the interaction relationships. The starting point for the relationships were based off of the studies found in the literature review. The results from analytical model of the standard wedges matched the experimental results very accurately. The analytical model of the modified wedge requires refinement. The results of the analytical model did not match the experimental observations as well as they should. However, the results still support the theory that the computer software can differentiate between standard and modified wedge geometries.
Burgoon, Justin Eugene. "Post-tensioned ribbed mat foundations on highly expansive soils". Manhattan, Kan. : Kansas State University, 2007. http://hdl.handle.net/2097/498.
Pełny tekst źródłaPino, Merino Denis Ademir. "Dynamic response of post-tensioned timber frame buildings". Thesis, University of Canterbury. Civil and Natural Resources Engineering, 2011. http://hdl.handle.net/10092/6598.
Pełny tekst źródłavan, Beerschoten Wouter Adrian. "Structural Performance of Post-tensioned Timber Frames under Gravity Loading". Thesis, University of Canterbury. Department of Civil and Natural Resources engineering, 2013. http://hdl.handle.net/10092/8735.
Pełny tekst źródłaSwenty, Matthew Kenneth. "The Investigation of Transverse Joints and Grouts on Full Depth Concrete Bridge Deck Panels". Diss., Virginia Tech, 2009. http://hdl.handle.net/10919/30214.
Pełny tekst źródłaPh. D.
Axson, Daniel Peter. "Ultimate Bearing Strength of Post-tensioned Local Anchorage Zones in Lightweight Concrete". Thesis, Virginia Tech, 2008. http://hdl.handle.net/10919/33711.
Pełny tekst źródłaMaster of Science
Dinevski, Elizabeth. "Randomized clinical trial assessing the effects of graft tensioning using semitendinosus and gracilis tendons in anterior cruciate ligament reconstruction". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0005/MQ42140.pdf.
Pełny tekst źródłaWoerheide, Andrew James. "Structural Performance of Longitudinally Post-Tensioned Precast Deck Panel Bridges". Thesis, Virginia Tech, 2012. http://hdl.handle.net/10919/34126.
Pełny tekst źródłaMaster of Science
Holthaus, Phillip Mathew. "Behavior at the Corners of Skewed, Single-Span, Cast-in-place, Post-tensioned Box Girder Bridges". OpenSIUC, 2009. https://opensiuc.lib.siu.edu/theses/420.
Pełny tekst źródłaKaram, Andrew. "Chloride Ingress into Submerged Concrete Under Sustained Load". Thèse, Université d'Ottawa / University of Ottawa, 2014. http://hdl.handle.net/10393/30484.
Pełny tekst źródłaPiyasena, Ratnamudigedara, i n/a. "Crack Spacing, Crack Width and Tension Stiffening Effect in Reinforced Concrete Beams and One-Way Slabs". Griffith University. School of Engineering, 2003. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20030606.165418.
Pełny tekst źródłaSrour, Mahdi. "Rocking system for seismic protection of reinforced concrete structures". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amslaurea.unibo.it/3255/.
Pełny tekst źródłaPiyasena, Ratnamudigedara. "Crack Spacing, Crack Width and Tension Stiffening Effect in Reinforced Concrete Beams and One-Way Slabs". Thesis, Griffith University, 2003. http://hdl.handle.net/10072/366060.
Pełny tekst źródłaThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Engineering
Full Text
Hockerman, Samantha Jo. "Laboratory testing of precast bridge elements, verification of post-tensioning forces and construction documentation of the Boone County IBRC accelerated bridge replacement project". [Ames, Iowa : Iowa State University], 2007.
Znajdź pełny tekst źródłaLopez-Molina, America Maria. "The Effect of Steel Strapping Tensioning Technique and Fibre-Reinforced Polymer on the Performance of Cross-Laminated Timber Slabs Subjected to Blast Loads". Thesis, Université d'Ottawa / University of Ottawa, 2018. http://hdl.handle.net/10393/38247.
Pełny tekst źródłaErdogdu, Murat. "In Plane Seismic Strengthening Of Brick Masonry Walls Using Rebars". Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/12610114/index.pdf.
Pełny tekst źródłaTeixeira, Fernando Ferrari. "Efeitos da radiação em transistores 3D tensionados". Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/3/3140/tde-19032015-165733/.
Pełny tekst źródłaThe effects caused by the X-ray radiation in n and p channel triple gate transistors, with and without mechanical tensioning, were theoretically and experimentally studied. After X-ray irradiation on the devices, it was observed a large variation in some of their characteristics, such as an increase in the slope of 40mV/dec threshold in larger devices, due to the creation of positive charges in the oxides, both for the buried oxide as for the gate oxide. The charges generated in the buried oxide had great influence on the current conduction through the back interface (silicon / buried oxide), since the buried oxide is thicker (145nm), which in turn significantly affected many other parameters. The formation of positive charges in the buried oxide caused distinct variations in the threshold voltage on the second interface, depending on the channel type of the transistor. In the case of n-channel MOS transistors, it was observed an increase in parasitic conduction from the second interface, whereas for p-channel MOS devices the current was minimized - due to the effects of radiation - generating an improvement in performance of such devices (it is possible to observe a reduction of subthreshold slope of 60 to 80mV/dec in the case of larger devices).. However, as the gate oxide is thinner than the buried oxide, large variations caused by the generated charges were not observed. When compared to the literature, the total accumulated dose was very high, therefore, a new round of radiation were performed, in which the distance between the sample and beam, and the exposure rate were changed. Thus, it was possible to observe the same effect described above, but with a total accumulated dose about 50 times lower. In both cases, the bias was not used during the radiation exposure, normally used to reduce the recombination, thereby increasing the the radiation effect.
Monteiro, Tiago Carvalho Leite. "Análise comparativa dos fatores influentes na tensão última de protensão em cabos aderentes e não aderentes". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2008. http://hdl.handle.net/10183/15300.
Pełny tekst źródłaUnbonded post-tensioning is characterized for allowing relative displacement between the tendon and the concrete adjacent fiber. The ultimate stress in the unbonded tendon is difficult to be obtained, because it is not only dependent on the deformed shape of a cross section, but on the whole deformations occurring in the tendon profile adjacent concrete. To evaluate this ultimate stress, it is necessary to integrate all curvatures along the whole element, in order to obtain the total tendon elongation. This can only be precisely obtained using numerical tools, due to the non-linear factors involved in the problem. Unbonded post-tensioning is becoming ever more used in Brazilian building construction. The main unbonded post-tensioning system uses the unbonded mono-strand, that joins the benefits of prestressing with the necessary building simplicity. Nevertheless, there is no research effort in Brazil compatible with the construction industry demand. This study seeks to contribute to the development of the national formulations design of unbonded posttensioning elements. This work is a continuation of a research being undertaken at PPGEC/UFRGS. A numerical model able to determine the behavior of unbonded posttensioned elements was first developed, followed by a parametric study about the main parameters influencing the ultimate stress in unbonded tendons. The present work traced a correlation between the results for unbonded elements, obtained from the parametric analysis, with results for bonded elements. The latter are easily obtained, because they are based on the compatibility of strains in the cross section. Numerical and analytical calculations were performed for the same prototypes studied in the previous research, but now considering the existence of bond in the tendons. The results showed greater increments in stress for the bonded cases and also greater ultimate resistance. It was also devised a calculation method able to determine the ultimate stress in the unbonded tendon using an analysis similar to strain compatibility, but with a reduction bond coefficient Lo/L. The initial results obtained for a third-point loading showed a good agreement, but that not happened for the results of distributed and concentrated loads. However, by an adjustment of the Lo/L coefficient, based on the data of the previous research, good agreement was observed for all loading types. The presented methodology was validated by comparing results with other prototypes analyzed by the numerical model, and also results of experimental studies carried out by several authors.
Giraldo-Londono, Oliver. "Finite Element Modeling of the Load Transfer Mechanism in Adjacent Prestressed Concrete Box-Beams". Ohio University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1397145708.
Pełny tekst źródłaMaurya, Abhilasha. "Experimental and Computational Investigation of a Self-Centering Beam Moment Frame (SCB-MF)". Diss., Virginia Tech, 2016. http://hdl.handle.net/10919/70866.
Pełny tekst źródłaPh. D.
Krauser, Gaelyn B. "Optimization of Two-Way Post-Tensioned Concrete Floor Systems". DigitalCommons@CalPoly, 2009. https://digitalcommons.calpoly.edu/theses/181.
Pełny tekst źródłaLima, Vanessa dos Santos. "Projeto de superestruturas de pontes de concreto protendido aplicando a técnica de balanços progressivos". Universidade Federal de São Carlos, 2011. https://repositorio.ufscar.br/handle/ufscar/4657.
Pełny tekst źródłaThis dissertation deals with main considerations on design of bridge superstructures, applying the cantilever balanced technique, bringing a procedure to be followed during pre-dimensioning this type of bridge. Presents the literature review used as the basis to dissertation, with the theories already studied on the subject. Based on these studies is drawn up the roadmap, involving the step of choosing the geometry, defining the structural scheme, the calculation of structural strain, calculating the losses of prestress, predimensioning of the prestressing steel considering the ultimate limit state and the service limit state, evaluation of the moment of closure and some important items for the detail section with steel. A numerical example is solved to illustrate the use of the concepts presented throughout the dissertation. Ends with considerations on the results obtained in the example and work and presents suggestions for future work.
Esta dissertação trata das principais considerações num projeto de superestruturas de pontes aplicando a técnica em balanços progressivos, fornecendo um procedimento para pré-dimensionamento deste tipo de ponte. Apresenta-se a revisão bibliográfica utilizada como base para dissertação, com as teorias já estudadas sobre o assunto. Com base nestas pesquisas elaborou-se um procedimento, envolvendo a etapa de escolha da geometria, definição do esquema estrutural, cálculo dos esforços solicitantes, cálculo das perdas de protensão, pré-dimensionamento da armadura de protensão levando em consideração o estado limite último e o estado limite de serviço, avaliação do momento de fechamento e alguns itens importantes para o detalhamento da seção com armadura. Um exemplo numérico é resolvido de forma a ilustrar a utilização dos conceitos apresentados ao longo da dissertação. Finaliza-se com as considerações sobre os resultados obtidos no exemplo e no trabalho e apresenta-se sugestões para trabalhos futuros..
Menegatti, Marcelo. "A protensão como um conjunto de cargas concentradas equivalentes". Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/3/3144/tde-12052005-222648/.
Pełny tekst źródłaThis work is a study about the representation of the prestressing through a CELG (Concentrated Equivalent Loads Group) in order to determine the internal forces and displacements in prestressed structures, due to prestressing. This study considers the concept of prestressing, deviation forces and immediate loss of prestressing. Furthermore some alternative methods to determine forces of prestressing are discussed including the case of hiperestatic structures e.g. initial forces and equivalent distributed loads. Next, the studied algorithm is discussed - CELG, (also known as Variable Force Method), its advantages and uses. Finally the use and precision of CELG is compared to some of the most traditional methods quoted beforehand and also its advantages and disadvantages.