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Fibre-to-Board - Validation of the Simulation Model and Development of Laboratory Methods to Receive Input Data / Fibre-to-board - validering av simuleringsmodellen och utveckling av laboratoriemetoder för att erhålla indataBoström, Charlotta, Rosén, Anna January 2006 (has links)
Fibre-to-board is a simulation model developed at Stora Enso Research Centre Karlstad. Within this model isotropic hand sheet properties are used as input data for prediction of the final multi ply board properties. In order to improve and verify the calculations from simulations in Fibre-to-board so that these will correspond better with the results from the measurements on the paper/board machine, it was requested at RCK to investigate the possibility to optimize the input data to the model. Standardized hand sheet forming always results in sheets with properties far away from those produced on a machine. Therefore the aim with this Master thesis was to modify the laboratory procedure to receive hand sheets with properties closer to machine sheets. To achieve this, it was investigated how different parameters affect the sheet properties and if the hand sheet making process could be improved. When freely dried sheets were investigated it was found that sheets pressed with a wire clothing between the blotting paper and the hand sheet were less cockled than sheets pressed against only blotting papers. These sheets also tend to have a higher density. The cockling i.e. as a result from shrinkage was also reduced when the sheets were dried between slightly weighted wire clothing. Neither wire clothing nor orientated blotting papers during pressing eliminate the influence of anisotropic blotters on the shrinkage for isotropic hand sheets. It was also examined how the fine material influences sheet properties. The results showed that an increase in fines content result in higher shrinkage, higher density, increased TSI, more cockling and decreased air permeability. Different pressing loads and an increased density did not have much influence on the shrinkage. The density for freely dried sheets increased with higher load, but the results did not reach machine sheet densities, when the laboratory platen press was used. It might be difficult to receive freely dried hand sheets with higher densities. This is because fibres in freely dried sheets tend to relax after pressing, which will influence the density. Another press than the platen press used in these studies might compensate this matter. An increased pressing load resulted in less cockled sheets. The basis weight did not seem to have that large affect on the shrinkage when using machine chest furnish, therefore the basis weight on hand sheets used as input data to the simulation model Fibre-to-board might not be that important. It was studied how different plies and SW/CTMP pulp in a mixture affect the shrinkage. The results showed that the shrinkage increased with a higher SW content. It was also found that there is a linear relation between the total shrinkage of a SW/CTMP pulp mixture and the shrinkage for each individual pulp. In order to verify the Fibre-to-board model a simulation finally was performed. Furnishes and CD profiles of board were collected from a particular board machine within the Stora Enso Group. Properties from hand sheets made of furnishes were used as input data and the machine CD profiles were used as references. The CD TSI value corresponded with the value received from measurements on the machine board, but the MD TSI value did not. The shrinkage calculated on machine sheets did not coincide with the shrinkage from the simulation in Fibre-to-board. There are insecurities in the results from shrinkage measurement on the board CD profile due to the lack of width measurement during the process, which complicates the validation of the Fibre-to-board model. / Fibre to board är en simulerings modell framtagen vid Stora Enso Research Centre Karlstad. Modellen används för att prediktera krympning och styrkeegenskaper hos en bestämd kartongbana. Indata till modellen hämtas ifrån isotropa laboratorieark. För att förbättra och verifiera erhållna resultat från simuleringsmodellen så att de korresponderar bättre med värden från kartongmaskinen fanns det ett önskemål från RCK om att undersöka möjligheten att optimera indata till modellen. Laboratoriearktillverkning enligt standard resulterar alltid i ark med egenskaper som ligger långt från maskin arkens. Därför är syftet med detta examensarbete att modifiera arktillverkningsmetoden så att laboratorieark med egenskaper närmare de för maskinark kan erhållas. För att lyckas med detta undersöktes det hur olika parametrar påverkar pappersegenskaperna och om tillverkningsmetoden kunde förbättras. Vid undersökning av fritorkade ark upptäcktes att ark som pressats med viraduk mellan läskark och laboratorieark blev mindre buckliga än ark som pressats med enbart läskark. Dessa ark hade också en något högre densitet. Buckligheten som är en följd av krympningen reducerades också när arken torkades mellan viraduk under lätt belastning. Läskarkens inverkan på de isotropa arken kunde inte elimineras genom att använda viraduk vid pressning, inte heller genom att växla läskarken så att deras MD riktning orienterades olika. Även finmaterialets inverkan på pappersegenskaperna undersöktes. Resultaten visade att ett ökat finmaterial innehåll ger ökad krympning, högre densitet, ökat dragstyvhetsindex, buckligare ark och en minskad luft permeabilitet. Det visade sig att olika presstryck ger arken en högre densitet men krympningen påverkades inte märkbart. Densitet i samma nivå som på maskinark kunde däremot inte erhållas med laboratorieplanpress. Detta kan bero på att fibrerna i fritorkade ark relaxerar efter pressning, vilket ger en lägre densitet. För att kunna få högre densitet kanske en annan press än den planpress som användes i dessa studier kan införas. Det kunde även konstateras att ett ökat presstryck ger mindre buckliga ark. I dessa studier, där ark tillverkades av färdiga skiktblandningar från maskinkar, hade inte ytvikten på arken någon större inverkan på krympningen. Detta tyder på att ytvikten på arken som används som indata inte har så stor inverkan vid simulering i modellen Fibre-to-board. Det undersöktes även hur skikten i ett två-skikts ark och en blandning av LF/CTMP massa påverkar krympningen. Resultaten visade att krympningen ökar med en högre andel LF och att det finns ett linjärt samband mellan den totala krympningen för en blandning av LF/CTMP massa och krympningen för de enskilda massorna. För att kunna verifiera beräkningsmodellen Fibre-to-board utfördes slutligen en simulering. Skiktblandningar och tvärsprofiler från kartong togs ut från en specifik pappers maskin inom Stora Enso koncernen. Egenskaperna på laboratorieark gjorda av skiktblandningarna användes som indata till simuleringsprogrammet och kartongprofilerna från pappersmaskinen användes som referens. Dragstyvhetsindex i CD stämde bra överens med de mätningar som gjordes på maskinarken, men dragstyvhetsindex i MD skiljde sig. Krympningen som beräknades på maskinarken överensstämde inte med det simulerade resultatet. Det förekommer en osäkerhet i krympmätningarna som gjordes på kartong profilerna, då det idag inte förekommer någon mätutrustning på pappersmaskinen, som bestämmer bredden mellan press- och torkpartiet. Detta komplicerar valideringen av Fibre-to-board modellen.
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Mixture Modeling and Outlier Detection in Microarray Data AnalysisGeorge, Nysia I. 16 January 2010 (has links)
Microarray technology has become a dynamic tool in gene expression analysis
because it allows for the simultaneous measurement of thousands of gene expressions.
Uniqueness in experimental units and microarray data platforms, coupled with how
gene expressions are obtained, make the field open for interesting research questions.
In this dissertation, we present our investigations of two independent studies related
to microarray data analysis.
First, we study a recent platform in biology and bioinformatics that compares
the quality of genetic information from exfoliated colonocytes in fecal matter with
genetic material from mucosa cells within the colon. Using the intraclass correlation
coe�cient (ICC) as a measure of reproducibility, we assess the reliability of density
estimation obtained from preliminary analysis of fecal and mucosa data sets. Numerical findings clearly show that the distribution is comprised of two components.
For measurements between 0 and 1, it is natural to assume that the data points are
from a beta-mixture distribution. We explore whether ICC values should be modeled
with a beta mixture or transformed first and fit with a normal mixture. We find that
the use of mixture of normals in the inverse-probit transformed scale is less sensitive toward model mis-specification; otherwise a biased conclusion could be reached. By
using the normal mixture approach to compare the ICC distributions of fecal and
mucosa samples, we observe the quality of reproducible genes in fecal array data to
be comparable with that in mucosa arrays.
For microarray data, within-gene variance estimation is often challenging due
to the high frequency of low replication studies. Several methodologies have been
developed to strengthen variance terms by borrowing information across genes. However, even with such accommodations, variance may be initiated by the presence of
outliers. For our second study, we propose a robust modification of optimal shrinkage variance estimation to improve outlier detection. In order to increase power, we
suggest grouping standardized data so that information shared across genes is similar
in distribution. Simulation studies and analysis of real colon cancer microarray data
reveal that our methodology provides a technique which is insensitive to outliers, free of distributional assumptions, effective for small sample size, and data adaptive.
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One-dimensional Real-time Signal Denoising Using Wavelet-based Kalman FilteringDurmaz, Murat 01 April 2007 (has links) (PDF)
Denoising signals is an important task of digital signal processing. Many linear
and non-linear methods for signal denoising have been developed. Wavelet based
denoising is the most famous nonlinear denoising method lately. In the linear case,
Kalman filter is famous for its easy implementation and real-time nature. Wavelet-
Kalman filter developed lately is an important improvement over Kalman filter, in
which the Kalman filter operates in the wavelet domain, filtering the wavelet coeffi-
cients, and resulting in the filtered wavelet transform of the signal in real-time. The
real-time filtering and multiresolution representation is a powerful feature for many
real world applications.
This study explains in detail the derivation and implementation of Real-Time
Wavelet-Kalman Filter method to remove noise from signals in real-time. The filter
is enhanced to use different wavelet types than the Haar wavelet, and also it is
improved to operate on higer block sizes than two. Wavelet shrinkage is integrated
to the filter and it is shown that by utilizing this integration more noise suppression
is obtainable. A user friendly application is developed to import, filter and export
signals in Java programming language. And finally, the applicability of the proposed
method to suppress noise from seismic waves coming from eartquakes and to enhance
spontaneous potentials measured from groundwater wells is also shown.
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Modeling The Effects Of Variable Coal Properties On Methane Production During Enhanced Coalbed Methane RecoveryBalan, Huseyin Onur 01 June 2008 (has links) (PDF)
Most of the coal properties depend on carbon content and vitrinite reflectance, which are rank dependent parameters. In this study, a new approach was followed by constructing a simulation input database with rank-dependent coal properties published in the literature which are namely cleat spacing, coal porosity, density, and parameters related to strength of coal, shrinkage, swelling, and sorption.
Simulations related to enhanced coalbed methane (ECBM) recovery, which is the displacement of adsorbed CH4 in coal matrix with CO2 or CO2/N2 gas injection, were run with respect to different coal properties, operational parameters, shrinkage and swelling effects by using a compositional reservoir simulator of CMG (Computer Modeling Group) /GEM module. Sorption-controlled behavior of coalbeds and interaction of coal media with injected gas mixture, which is called shrinkage and swelling, alter the coal properties controlling gas flow with respect to injection time. Multicomponent shrinkage and swelling effects were modeled with extended Palmer and Mansoori equation.
In conclusion, medium-volatile bituminous coal rank, dry coal reservoir type, inverted 5-spot pattern, 100 acre drainage area, cleat permeability from 10 to 25 md, CO2/N2 molar composition between 50/50 % and 75/25 %, and drilling horizontal wells rather than vertical ones are better selections for ECBM recovery. In addition, low-rank coals and dry coal reservoirs are affected more negatively by shrinkage and swelling. Mixing CO2 with N2 prior to its injection leads to a reduction in swelling effect. It has been understood that elastic modulus is the most important parameter controlling shrinkage and swelling with a sensitivity analysis.
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Freiräume in schrumpfenden StädtenRößler, Stefanie 29 December 2010 (has links) (PDF)
Schrumpfungsprozesse bestimmen seit Ende der 1990er Jahre zunehmend die Stadtentwicklung in den Neuen Bundesländern. Demografischer und ökonomischer Wandel gelten als wesentliche Ursachen für einen massiven Nachfragerückgang und erhebliche Leerstände im Wohnungsbestand. Im Zuge des Programms "Stadtumbau Ost“ werden die ungenutzten Wohngebäude abgerissen. Sowohl in Stadtzentren als auch in Randlagen erstrecken sich nicht mehr bebaute Areale, da sich nur für wenige Freiflächen eine bauliche Nachnutzung findet. Freiraumplanerische Konzepte und Maßnahmen werden möglich, aber auch notwendig für den Umgang mit den frei gewordenen Flächen und bieten gleichzeitig Potenziale zur Verbesserung der städtischen Umwelt- und Lebensqualität.
Die vorliegende Forschungsarbeit beschäftigt sich mit der Frage, welche Bedeutung Freiräume im Umgang mit räumlichen Schrumpfungsprozessen haben und wo die Chancen und Grenzen der Freiraumplanung beim Stadtumbau liegen. Die Autorin legt die gegenwärtigen Rahmenbedingungen der Freiraumplanung dar und setzt sich mit Stadtmodellen, städtebaulichen Leitbildern und dem Verständnis von Natur und Landschaft in der schrumpfenden Stadt auseinander. Am Beispiel der Großstädte Chemnitz, Halle und Leipzig werden die Strategien, Entscheidungen und Handlungsansätze der Freiraumplanungspraxis schrumpfender Städte analysiert. Die Ansätze werden beschrieben und mit Blick auf ihre Eignung und Zukunftsfähigkeit für die Gestaltung des Stadtumbauprozesses diskutiert. / Since the second half of the 1990’s, the new federal states of Germany have undergone dramatic demographic and economic change, which, among other things, has led to the ongoing phenomenon of shrinking cities. The work at hand deals with the issue of what the relevance of urban green spaces is in light of the spatial shrinking processes and where the opportunities and limitations are concerning green space planning within urban restructuring.
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Zum Problem der Netzschrumpfung in der Hernienchirurgie / Problem of mesh-shrinkage in hernia-surgeryForster, Henrik 08 February 2011 (has links)
No description available.
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Long-Term Deflection Of One-Way Concrete Slab Strips Containing Steel And GFRP ReinforcementDarabi, Mohammadali 14 September 2011 (has links)
Fibre reinforced polymers (FRP’s) are considered an alternative to steel reinforcement in concrete structures because of their noncorrosive nature and nonmagnetic properties. FRP materials are, however, brittle and have a lower stiffness compared to steel. The latter property can lead to deflection and crack control problems in FRP-reinforced concrete flexural members under service loads. A considerable amount of information is available for short-term deflection of FRP-reinforced concrete members, but data on long-term deflections are scarce.
This study presents the results of monotonic (short-term) and sustained (long-term)
loading tests of 12 concrete shallow beams reinforced with either steel or glass FRP
(GFRP) bars. The short-term load-deflection responses of the members are evaluated
using existing deflection prediction models (Branson’s and Bischoff’s), and the long-term deflection results (monitored over a period of one year) are used to evaluate the existing ACI code and CSA standard approaches for estimating long-term deflection. The GFRP-reinforced concrete beams exhibited greater amounts of both immediate deflection (under sustained load) and long-term deflections over time, than the steel-reinforced concrete beams. The long-term deflections of both the steel- and GFRP-reinforced concrete beams are overestimated when using the ACI and CSA approaches. Although ACI Committee 440 recommends use of lower values of the long-term deflection multiplier for GFRP-reinforced concrete beams, results obtained from this study suggest that the same longterm multiplier values may be used for GFRP- and steel-reinforced concrete beams loaded at between 115 to 157 days of concrete age.
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Properties and Distortion of Douglas-fir with Comparison to Radiata PineWang, Eric Yunxin January 2009 (has links)
The objectives of this study were to investigate stability related basic wood properties and to determine stability performance of New Zealand grown Douglas-fir and those of radiata pine wood. In this study, nine 60-year old Douglas-fir trees and thirteen 26-year old radiata pine trees were selected from forests in Canterbury region. From these trees, 36 discs of 200 mm thick (13 for Douglas-fir and 23 for radiata pine) and 388 boards with dimensions of 100mm x 50mm x 4.8m (210 fro Douglas-fir and 178 fr radiata pine) were prepared.
From the prepared discs, 515 specimens (204 for Douglas-fi and 211 for radiata pine) were prepared for green moisture content (MC) and basic density measurements, The same total number of 515 specimens (205 for Douglas-fir and 210 for radiata pine) were also prepared for shrinkage measurements. From the green MC specimens, green weight, volume and oven-dry weight were measured while for the shrinkage specimens, dimensions and weights were measured at equilibrium for nine humidity conditions. These data were used to analyse basic wood properties and moisture uptake characteristics for both Douglas-fir and radiata pine. Variation of shrinkage within a tree and between trees was also studied for both species. After this, selected specimens (36 for Doulas-fir and 36 for radiata pine) were further tested in water immersion for water repellence examination.
The 388 full size boards (100mmx50mmx4.8m) were used for studies on distortion and acoustic properties at a sawmill (Southland Timber Ltd.). Dimensions, weights and acoustic velocity were measured from each board before and after drying. These data were used to analyse distortion and strength characteristics for both Douglas-fir and radiata pine. Comparison of the relative stability of full sized Douglas-fir and radiata pine structural timber was investigated in this study.
The results from small sample study confirmed that Douglas-fir is much stronger, has lower longitudinal shrinkage and lower gradient in corewood which can be used to explain the better dimensional stability of Douglas-fir than radiate pine although there is significant variability in the shrinkage for both Douglas-fir and radiate pine. In water immersion tests, Douglas-fir has better water repellency property than radiata pine over 2000 hours period during water immersion.
Under the same commercial practice in sawing and kiln drying, it is clearly shown that Douglas-fir timbers were straighter with lower levels of distortion than radiata pine at similar final moisture content. It is also interesting to note that the final moisture content in a range of 13-18% for Douglas-fir did not have significant impact on timber distortion but a negative trend was observed for radiata pine with MC in a range of 9 -14%. Tree heights showed clear influence on twist for radiata pine timbers, but it was not clearly observed from Douglas-fir timbers. Corewood proportion is found to have negative impact on the timber distortion for both Douglas-fir and radiata pine. Douglas-fir timbers showed much higher average acoustic MOE value than radiata pine timbers at similar final moisture content.
Because of the various proportion of corewood, the shrinkage varied greatly along the stem height and along the disc radius direction for the two species. This variation caused the difference of distortion between corewood, outerwood and transition wood, but the difference between butt log, middle log and top log is inconsistent. Therefore, it is recommended that the corewood proportion to be a criterion for the timber pre-sorting.
Variation of stability performance between trees was also found to be significant for the two species, and methods need to be developed for log sorting as well to reduce the timber distortion degradation. Non-destructive testing method such as acoustic tool may be offered to be a new approach for sorting logs, but it is also necessary to be aware of the significant difference between species.
The outcome from this project includes better understanding of Douglas-fir for structural applications. The conclusion can be drawn that Douglas-fir has superior quality for its strength, durability and moisture resistance. Douglas-fir is also claimed to have uniform properties and thus to be more stable compared to radiata pine. Douglas-fir timbers showed much higher acoustic MOE value than radiate pine timbers as similar final moisture content.
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Krympstudie inom additiv tillverkning : En fallstudie med elektronstrålesmältning av Ti6Al4VBergström, Anton, Bredhe, Emelie January 2018 (has links)
I detta projekt har en studie av krympning vid additiv tillverkning i materialet Ti6Al4V gjorts, detta för att analysera hur utskrifter i olika storlekar och riktningar påverkas. Arbetet har genomförts av två studenter vid Mittuniversitetet i Östersund och görs på uppdrag av universitetets forskningssida. I projektet har förstudier gjorts för att lägga en grund för arbetet. Under förstudierna hittades information om att krympningen kunde minskas med hjälp av att använda stödmaterial i utskrifterna. Design för de detaljer som ska skrivas ut har valts ut med hjälp av tidigare forskning där trappor varit rekommenderat för att lätt kunna avgöra vad som händer i olika delar av en utskrift. Även detaljer för mätning av vassa kanter och avrundningar skrevs ut för att kunna kontrollera dessa om tid blev över men dessa mättes aldrig då fokus under hela detta arbetet legat på trapporna. Trapporna skrevs ut i tre olika storlekar. De skrevs ut både med och utan stöd och i både liggande och stående led i en EBM-maskin, Arcam S12. När de blivit utskrivna mättes de med hjälp av mikroskopet “Dino-Light edge Digital Microscope”. Informationen som kommit fram ur dessa mätningar har sedan lagts in i ett Excel dokument där tabeller och grafer tagits fram för att göra det lätt att uppfatta tendenser. De utmärkande tendenser som upptäcktes var att en större krympning alltid inträffade vid det första och tredje steget i en utskrift. Detta inträffade oavsett vilken storlek av trappor som kontrollerades och kunde undvikas med hjälp av att använda stödmaterial. I modellerna med stödmaterial kunde inte speciella tendenser synas och den krympning som syns i dessa mätningar kan bero på fel från den mänskliga faktorn vid mätningen. Trenderna är tydliga i de detaljer som skrivits ut utan stödmaterial. Detta fenomen kan bero på att materialet i skrivplattan som finns i skrivaren inte är detsamma som Ti6Al4V, vilket kan ha en inverkan på det utskrivna materialet i de lagren som är närmast skrivplattan. Krymp i detaljerna beror också på att pulvret i skrivaren blir mindre då det smälter vilket gör att varje lager inte får förväntad/ önskad tjocklek. Detta är ett problem som följer med genom hela utskriften oavsett om stödmaterial används eller ej. Arbetet som gjorts anses lyckat. / This project is a about studying and anylazing shrinkage during the use of a EBM-machine in the material Ti6A14V. The study is done to anaylze how prints of diffrent size and printing direction are affected by the shrinkage. The project is done by two students at Mid Sweden University in Östersund and the project is requested by the research department of the university. Research has been made before the start of the project to give the students a solid understanding in the matter. During the research for information it was found that the shrink could be minimized by using supportmaterial in the print. The design for the parts that was going to be printed have been chosen through earlier studies of the matter where stairs was recommended to easy be able to see what goes on in the different parts of a print. Some details was also created so that measurements considering sharp edges and round details could be checked for deformations if there was enough time. Those were never measured since all the time of this project was focused around the stairs. The stairs were printed in three different sizes. They were also printed with and without supportmaterial and both standing up and lying down in the printer EBM Arcam S12. When the parts had been printed they were measured with a microscope called “Dino-Light edge Digital Microscope”. The information gotten from these measurements were put into a Microsoft Excel document where tables and graphs were created to make it easy to spot the tendencies of the prints. The tendencies that were noticeable was that the first and third step of every print had more shrink than the others. This occurred no matter the size the stairs were but did not occur in the parts printed with supportmaterial. No tendencies were noticed in the prints with supportmaterial and the shrinkage that was noted in these prints might also be because of the human factor. The trends are clearly visible in the parts printed without supportmaterial. This might be because of the different material in the printing plate that is stainless steel instead of Ti6Al4V. This might cause problem for the layers that are printed closest to the plate. The reason for shrinking in the details is also because of the fact that the powder that is being printed gets melted and therefor shrinks. This results in a thicker layer of powder everytime the powder is applied to the printing surface. This is a problem that goes on throughout the whole print no matter if supportmaterial is used or not. The work completed is considered to be well done. / <p>Betyg: 180809</p>
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Análise numérica de vigas mistas aço-concreto pelo método dos elementos finitos : modelos para os efeitos de longa duração e protensão interna / Numerical analysis of composite steel-concrete beams by the finite element method : models for the long-term effects and internal prestressingMoreno, Julián Camilo Ávila January 2016 (has links)
As vigas mistas configuram uma atrativa solução estrutural para pequenas e grandes obras na engenharia civil. O emprego deste tipo de estruturas proporciona: melhor aproveitamento das características de cada material, maior rapidez na construção e economia. Esta pesquisa da continuidade aos trabalhos de Tamayo (2011) e Dias (2013); apresenta-se um modelo numérico que emprega o método dos elementos finitos para avaliar o comportamento de estruturas do tipo viga mista, com foco na consideração dos efeitos de longa duração do concreto: fluência e retração; e à inclusão da protensão interna do tipo aderente, aplicada sob a laje de concreto. Implementaram-se seis modelos para predição dos fenômenos de longa duração: ACI 209R-92, Bazant-Baweja B3, CEB MC90, CEB MC99, CEB MC10 e GL2000, e disponibilizou-se uma ferramenta estatística que permite sua correta comparação. O cabo de protenssão é modelado de maneira discreta dentro do elemento de concreto e posteriormente são definidas as contribuições que o mesmo faz ao elemento de casca do concreto no qual está inserido. O Software GiD foi empregado nas etapas de pré e pós processamento, customizando sua interface para a atribuição das propriedades do problema. A validação da simulação numérica foi efetuada a partir da modelagem de 14 vigas no total, os espécimenes correspondem a vigas tanto simplesmente apoiadas como contínuas. O programa desenvolvido é capaz de modelar adequadamente estruturas do tipo viga mista, com protensão aderente instalada na laje de concreto; considerando uma análise ao longo do tempo e levando em conta os efeitos da fluência e da retração que afetam o concreto. / The composite beams constitute an attractive structural solution for small and large projects in civil engineering. The use of such structures provides better use of the characteristics of each material, faster construction and economy. This research continues the work of Tamayo (2011) and Dias (2013); it presents a numerical model employing the finite element method to evaluate composite beam structures, focusing on the long-term effects of concrete: creep and shrinkage; and the inclusion of internal adherent prestressing, applied under the concrete slab. Six models were implemented for the prediction of long-term effects: ACI 209R-92, Bazant-Baweja B3, CEB MC90, CEB MC99, CEB MC10 and GL2000, and provided a statistical tool that allows the correct comparison between them. The prestressed cable is modeled discretely within the concrete element and are further defined the contributions that it makes to the concrete shell element in which it is inserted. The GiD Software was used in the stages of pre and post processing, and its interface was customized for assigning the problem properties. The validation of numerical simulation was performed by full modeling 14 beams; the specimens correspond to both simply supported as continuous beams. The developed program is able to adequately model prestressed composite beam structures; considering the long-term effects of creep and shrinkage, that affects the concrete.
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