Submitted by Romulo Rezende Dias null (romulordias@yahoo.com.br) on 2016-03-17T20:12:40Z No. of bitstreams: 1 Dissertação Romulo Rezende Dias corrigida.pdf: 4489690 bytes, checksum: 9af841b8b53dd7ecfeee3773848e7168 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-03-21T18:27:40Z (GMT) No. of bitstreams: 1 dias_rr_me_guara.pdf: 4489690 bytes, checksum: 9af841b8b53dd7ecfeee3773848e7168 (MD5) / Made available in DSpace on 2016-03-21T18:27:40Z (GMT). No. of bitstreams: 1 dias_rr_me_guara.pdf: 4489690 bytes, checksum: 9af841b8b53dd7ecfeee3773848e7168 (MD5) Previous issue date: 2016-02-19 / O uso de madeira de pinus na construção civil é cada vez maior e saber trabalhar suas características, vantagens e desvantagens é essencial para o sucesso do produto. O presente trabalho tem por objetivo estudar a influência da largura das lamelas e do arranjo físico dos anéis de crescimento em painéis de madeira de Pinus taeda coladas lateralmente (EGP) utilizados na fabricação de batentes, seguindo as exigências da ABNT-NBR 15.930 (2011), a fim de determinar a melhor combinação para o melhor desempenho físico do produto. Para tanto, trabalhou-se com o fatorial completo para dois fatores e quatro níveis, sendo i. largura das lamelas de 32 mm, 56 mm, 75 mm e 112mm; e ii. arranjo dos anéis: lamelas radias, lamelas tangenciais, lamelas cruzadas e lamelas com emendas de topo tipo finger joint. Os 48 corpos de prova (03 para cada combinação) de batente de EGP com 2120 x 220 x 32mm, com teor de umidade entre 8% e 12% e densidade aparente entre 400 kg.m-3 e 600 kg.m-3 foram produzidos numa indústria madeireira da cidade de Sengés/PR. Utilizou-se a análise estatística de variância (ANOVA) para investigar a influência dos fatores e suas interações nas seguintes respostas: aspecto visual, variação da umidade, variação da densidade, variações dimensionais de largura e espessura e desvios de forma (empenamento: encurvamento, arqueamento e encanoamento). Os resultados mostraram que os dois fatores e suas interações exerceram influência com nível de significância de 1% sobre os desvios de forma. Os melhores resultados foram para painéis produzidos com lamelas de 32 mm e 56 mm, com arranjo cruzado ou radial. As demais respostas não foram influenciadas de forma significativa pelos fatores e suas interações. / The use of pine wood is increasing and for the success of its products it is essential to have the know-how to work its features, advantages and disadvantages. The objective of this study is to evaluate the influence of batten widths and the physical arrangement of growth rings in Edge Glued Panel of Pinus taeda used in the manufacture of door frames, according the requirements of ABNT-NBR 15.930 (2011) to determine the best combination for better physical performance of the door frame. Experimental tests considered the full factorial method using two factors and four levels, with batten widths of 32mm, 56mm, 75mm and 112mm; and arrangement of the growth rings: radial, tangential, crossed and plates with top amendments type finger joint. The 48 samples (03 from each combination), with 2120 x 220 x 32 mm, with a moisture content between 8% and 12% and an apparent density between 400 kg.m-3 and 600 kg.m-3 were produced in a wood factory in Sengés/PR/Brasil. The statistical analysis of variance (ANOVA) was used to investigate the influence of the factors and their interactions in the following responses: visual appearance, moisture content variations, density variations, dimensional variations in width and thickness and deviations in shape (warping: bending, curving and curling). The results showed that both factors and their interactions exerted influence with a significance level of 1% on the deviations of form. The best results were to EGP produced with batten widths of 32 mm and 56 mm, with radial or crossed arrangement. The factors and their interactions did not significantly influence the other answers.

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Kan snedskarvning vara ett ekonomiskt lämpligt komplement till fingerskarvning? Kvistfritt listmaterial av furu är mycket eftertraktat inom träindustrin där fingerskarvning numera är den mest förekommande metoden. Det är viktigt att listmaterial har en hanteringsstyrka god nog för att hålla ihop vid montering eftersom konstruktionsstyrkan inte är den begränsande faktorn. Denna studie innehåller en jämförelse i draghållfasthet för lister gjorda med fingerskarv, MDF och snedskarv där det lägsta vinkelförhållandet som uppfyller kraven på skarven är sökt från 1:1 till 1:5. Tidigare tester framhåller förhållandet 1:8 när det är till för konstruktionsändamål, denna studie hävdar att 1:3 är tillräckligt för lister. / Could scarf jointing be an economical suitable complement to finger jointing? Knot-free lath material of pine wood is highly requested in the timber industry where finger jointing nowadays is a commonly used method. It is important that the lath material has a handling strength good enough to hold the assembly since structural strength is not the limited factor. This study contains a comparison of tensile strength in laths made of finger joints, MDF (Medium Density Fibreboard) and scarf joints where the lowest ratio of angular relationship that meets the demands of the scarf is searched from 1:1 to 1:5. Previous testing only holds a ratio of 1:8 for construction purposes whereas this study claims a result of 1:3 for laths.

Friction stir welding (FSW) of HSLA steel commonly produces a hard zone (HZ) on the advancing side (AS) of the weld. Despite its detrimental effects on weld toughness, the mechanisms of its formation have not been thoroughly investigated and are not well understood. This paper investigates the various mechanisms in FSW believed to affect the weld HZ, namely: strain, strain-rate, peak temperature and cooling rate. Gleeble tests indicate that strain and strain rate have negligible effects on weld HZ with cooling rate and peak temperature as dominant effects. Jominy tests resulted in cooling rate having 270% greater influence than peak temperature on the formation of lath ferrite microstructures similar to what is observed in the HZ of FSW X65. Comparing weld HZ microstructures to Jominy tests, it is estimated that cooling rates on the AS of the weld are at least 150°C/s higher than the retreating side. Reducing the cooling rate on the AS will likely lead to an improved microstructure at the weld HZ.

[pt] Esta dissertação mostra estudos de aplicações e revestimento do fibrobarro em diferentes contextos dentro do Estado do Rio de Janeiro. Através da pesquisa efetuada dentro e fora do Laboratório de Investigação em Livre Desenho (LILD) foram desenvolvidas possibilidades de aplicação do fibrobarro aproveitando os recursos disponíveis. A pesquisa relata alguns materiais já utilizados para a cobertura de construções em materiais biocompatíveis. Durante o processo da pesquisa avergou-se possibilidades para a fabricação de compósitos, principalmente na abrangência de possíveis fibras quando o fibrobarro não for utilizado como principal elemento estrutural. O revestimento também é pesquisado com destaque para o uso da pasta de cal hidratada. Ao efetuar a pesquisa de campo em paralelo aos estudos em laboratório foi possível perceber a importância do gestual no ato de fazer artesanalmente objetos que buscam ser perenes respeitando o ambiente local e considerando-se o seu descarte. Durante o processo de pesquisa também foi observado a construção dos objetos arquitetônicos com voluntários de diferentes contextos socioeconômicos o que possibilitou perceber a importância dessa diversidade para atingir a convivencialidade (Illich, 1976) e como uma metodologia atenta e sensível, fundamental para desenvolvermos uma verdadeira ciência de construção respeitando as características sociais e ambientais de cada região. / [en] This master thesis studies shows applications and finishes of fibersoil in different contexts inside the State of Rio de Janeiro. Through the work done inside and outside the Laboratory of Research in Free Drawing (LILD) investigate possible applications of fibersoil using the resources available. At the beginning of the work trace is already some materials used for covering buildings made with biocompatible materials inside and outside the LILD. During the process of research we discovered some possibilities for the manufacture of composites, especially in the range of possible using of fibers when it is not used as the main structural element. We also researched some possibilities for finishing construction of fibrosoil more careful in the use of hydrated lime paste. When we make the field research in parallel with laboratory studies we realized the importance of the gestures in the act of making objects that seek to be a evergreen respecting the local environment and considering your disposal. During the research process we also observed the construction of architectural objects with volunteers from different socioeconomic contexts which enabled us to realize the importance of gesture and an attentive and sensitive methodology is important to develop a true science of construction respecting the social and environmental characteristics of each region.

[pt] A busca de modelos de desenvolvimento que minimizem ao máximo o impacto sobre o ambiente em que vivemos é o ideal a ser alcançado. Os benefícios proporcionados através dos objetos construídos pelo homem neste ambiente são reflexos de uma interferência adequada ao espaço habitado. Neste trabalho esta interferência é produzida pelas construções habitacionais. No bairro do Monteiro, área rural do município de Itamonte-MG, notou-se um processo de deterioração e empobrecimento dos conhecimentos construtivos tradicionais, inclusive a taipa. Apesar da eficiência destas construções, observou-se a gradativa degradação de alguns modos construtivos tradicionais no local. Os conhecimentos originais, de manejo de materiais adequado ao clima e local, foram abandonados e esquecidos. O trabalho de pesquisa que se apresenta aqui tem como objetivo fazer das técnicas construtivas consagradas, e que se utilizam de solo cru, um objeto de estudo a fim de resgatar conhecimentos e procedimentos, aperfeiçoá-los, adaptá-los a determinado local e mantê-los em desenvolvimento. A aplicação da metodologia do Laboratório de Investigação em Living Design ( LILD), será a base de sustentação dos experimentos que se realizarão ao longo do trabalho. Resumidamente esta metodologia propõe primeiramente após um estudo das características do contexto local, experimentos iniciais e empíricos, em campo e em laboratório, tendo sempre a participação e atuação dos membros da comunidade. A investigação tem prosseguimento com ensaios científicos, que permitem o controle e o aperfeiçoamento nos procedimentos utilizados em tais técnicas. Posteriormente a estas etapas aplicam-se novamente outros experimentos práticos no campo e novamente com participação da comunidade. Do compartilhamento das atividades do pesquisador e dos obreiros locais, resultou uma troca de informações que permitiu a aplicação do aprendizado da produção e da pesquisa num mesmo objeto. Aparecem com destaque no percurso do trabalho, experimentos que demonstraram a importância da utilização das fibras, não somente como agente estabilizador do solo, mas permitindo sim, novas possibilidades de vedações leves, principalmente como elemento definidor de compósitos em forma de lâminas e cascas. / [en] Our goal is the search for development models that minimize environment impact. The benefits deriving from mans constructed objects on these environments reflect an adequate interference to the inhabited space. The resulting interference from habitation constructions is described. A process of deterioration and impoverishment of traditional constructive knowledge, including mud wall, was detected in the rural area of Monteiro, district of Itamonte in Minas Gerais, Brazil. In spite of the efficiency of these types of construction, the gradual degradation of some of the traditional constructive modes was verified. The original knowledge concerning the adequacy of materials to the climate and locality was abandoned and forgotten. The present research aims at studying the known constructive techniques, which use raw soil in order to recover their knowledge and procedures, to improve and adapt them to a certain place, and keep their development. The methodology of the Laboratory of Investigation in Living Design - LILD supports the experiments done along the work. In a few words, the methodology proposes a context study of local characteristics performing initial empiric experiments. This work is carried out at Monteiro and in the laboratory, always counting on the participation of community members. The investigation follows with scientific tests that allow for the control and improvement of procedures adopted in the studied techniques. The next step is to go back to the rural area and make other practical experiments, again, with the participation of community members. The result of shared activities between the researcher and local workers was the exchange of information concerning the production and the research itself, which allowed for the application of learned knowledge in the same object. Experiments along the way demonstrate the importance of utilizing fibers, not only as agents to stabilize soil, but also allowing for new light sealing possibilities, especially as main elements of composites in the form of plates and barks.

High strength low alloy (HSLA) steels have been developed to simultaneously have high yield strength and high fracture toughness. However, in practical applications steel must be welded. Traditional arc welding has proven detrimental to the fracture toughness of HSLA steels. Friction stir welding has recently shown mixed results in welding HSLA steels. The range of welding parameters used in these recent studies however has been very limited. With only a few welding parameters tested, the effect of spindle speed, travel speed, and heat input on the fracture toughness of friction stir welded HSLA steel remains unknown. To understand how the friction stir welding process parameters affect fracture toughness, double sided welds in API X80 were performed and analyzed. Results show that at room temperature friction stir welded API X80 exceeded industry minimum fracture toughness requirements in both the API Standard 1104 and DNV-OS-F101 by 143% and 62%, respectively. The process parameters of spindle speed and HI have been shown to effectively control the fracture toughness of the stir zone. Relationships have been established that show that fracture toughness increased by 85% when spindle speed decreased by 59% and heat input decreased by 46%.

The use of pre-hardened mold steels has increased appreciably over the years; more than 80% of the plastic mold steels are used in pre-hardened condition. These steels are delivered to the customer in finished state i.e. there is no need of any post treatment. With hardness around ~40HRC, they have properties such as good polishability, good weldability, corrosion resistance and thermal conductivity. Machinability is a very important parameter in pre-hardened mold steels as it has a direct impact on the cost of the mold. In normal machining operations involving intricate or near net shapes, machining constitutes around 60% of the total mold cost. Efforts are underway to explore every possible way to reduce costs associated with machining and to make production more economical. All the possible parameters which are considered to affect the machinability are being investigated by the researchers. This thesis work focuses on the effect of prior austenite grain size on the machinability of pre-hardened mold steel (Uddeholm Nimax).  Austenitizing temperatures and holding times were varied to obtain varying grain sized microstructures in different samples of the same material. As it was difficult to delineate prior-austenite grain boundaries, experimental and empirical methods were employed to obtain reference values. These different grain sized samples were thereafter subjected to machining tests, using two sets of cutting parameters. Maximum flank wear depth=0.2mm was defined for one series of test which were more akin to rough machining, and machining length of 43200mm or maximum wear depth=0.2mm were defined for second series of tests which were similar to finishing machining. The results were obtained after careful quantative and qualitative analysis of cutting tools. The results obtained for Uddeholm Nimax seemed to indicate that larger grain sized material was easier to machine. However, factors such as retained austenite content and work hardening on machined surface, which lead to degradation of machining operations were also taken into consideration. Uddeholm Nimax showed better machinability in large grained samples as retained austenite(less than 2%) content was minimal in the large grained sample. Small grained sample in Uddeholm Nimax had a higher retained austenite (7+2%) which resulted in degradation of machining operation and a lesser cutting tool life.

This thesis concerns the mathematical modelling of phase transformations with a special emphasis on martensitic phase transformations and their application to the modelling of steels. In Chapter 1, we develop a framework that determines the optimal transformation strain between any two Bravais lattices and use it to give a rigorous proof of a conjecture by E.C. Bain in 1924 on the optimality of the so-called Bain strain. In Chapter 2, we review the Ball-James model and related concepts. We present some simplification of existing results. In Chapter 3, we pose a conjecture for the explicit form of the quasiconvex hull of the three tetragonal wells, known as the three-well problem. We present a new approach to finding inner and outer bounds. In Chapter 4, we focus on highly compatible, so called self-accommodating, martensitic structures and present new results on their fine properties such as estimates on their minimum complexity and bounds on the relative proportion of each martensitic variant in them. In Chapter 5, we investigate the contrary situation when self-accommodating microstructures do not exist. We determine, whether in this situation, it is still energetically favourable to nucleate martensite within austenite. By constructing different types of inclusions, we find that the optimal shape of an inclusion is flat and thin which is in agreement with experimental observation. In Chapter 6, we introduce a mechanism that identifies transformation strains with orientation relationships. This mechanism allows us to develop a simpler, strain-based approach to phase transformation models in steels. One novelty of this approach is the derivation of an explicit dependence of the orientation relationships on the ratio of tetragonality of the product phase. In Chapter 7, we establish a correspondence between common phenomenological models for steels and the Ball-James model. This correspondence is then used to develop a new theory for the (5 5 7) lath transformation in low-carbon steels. Compared to existing theories, this new approach requires a significantly smaller number of input parameters. Furthermore, it predicts a microstructure morphology which differs from what is conventionally believed.