Made available in DSpace on 2014-06-11T19:27:12Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-12-16Bitstream added on 2014-06-13T19:35:01Z : No. of bitstreams: 1 dias_gcb_me_guara.pdf: 1781054 bytes, checksum: 9aebafdc1f0f4dac5ad0f6b86d3c63ff (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O presente trabalho estudou as variáveis de fabricação no processo na linha de galvanização contínua por imersão a quente, simulando o processo de conformação e a cura da pintura nas montadoras, visando avaliar as condições de deformação, tempo, temperatura e o envelhecimento desde o tempo de estocagem até a conformação dos aços ultra baixo carbono semi-estabilizado ao Nióbio para obtenção de índices de bake hardening (IBH) satisfatórios, visando o atendimento e a garantia das especificações dos aços BH180 e BH220. Para a execução das análises, utilizou-se o laboratório de controle da qualidade da empresa, onde foram retirados corpos de prova para ensaios de tração e do índice bake hardening seguindo os procedimentos conforme a norma requisitada. O ensaio padrão de bake hardening (BH) consiste em, deformar o corpo de prova até 2%, interromper o ensaio, aquecer o material na estufa por 20 minutos a 170ºC e após resfriamento, dar continuidade ao ensaio. O cálculo do índice de BH foi especificado segundo a norma DIN BS EN 10325. Este trabalho visou a comparação entre dois testes de envelhecimento, um em condição natural e outro artificial. Na condição natural, os corpos de prova foram deixados em temperatura ambiente durante o período de seis meses e, na condição artificial, as variáveis tempo e temperatura foram analisadas. A garantia do tempo de estocagem está sendo discutida entre as montadoras e as usinas. A condição padrão para a simulação do ensaio de aços bake hardening, avaliou a influência de cada variável e verificou que o índice de BH está dentro do especificado em norma, sendo encontrado o valor de 49,0 MPa para o aço BH180 e de 45,0 MPa para o aço BH220. As variáveis mencionadas são importantes para o incremento do índice de BH principalmente a pré-deformação... / This paper studied the variables in the manufacture process in continous hot dipped galvanizing line, simulating the process of drawing and curing of paint in the automakers, to evaluate the conditions of deformation, temperature, time and aging from storage time to drawing of ultra low carbon steel semi-stabilized to achieve a reasonable bake hardening index (BH) in order to find the specifications and warranty BH180 and BH 220 steels. For the application of tests, it was use the quality control laboratory of the company`s, where specimens were removed for tensile tests and bake hardening index (BH) following the standard procedures as required. The bake hardening (BH) pattern test consists of deforming the specimen until 2%, stop the test, after heating the material in an oven for 20 minutes at 170 ° C and after air cooling, continue the trial. The calculation of a reasonable bake hardening index (BH) was specified according to DIN BS EN 10325. This study aimed to compare two aging tests, one in natural and the other one in artificial condition. In natural condition, the specimens were left at room temperature for a period of six months, and in artificial condition, time and temperature variables were analyzed. The warranty of the storage time is being discussed between the automakers and steel plants. The default condition for the simulation of the bake hardening steels test, evaluated the influence of each variable and found out that bake hardening index (BH) is within the specified standard, and with values of 49.0 MPa for BH180 steel and 45.0 MPa for BH220 steel. The variables mentioned are important for increasing the bake hardening index (BH) mainly pre-deformation has a significant influence. The steels studied seem not to have great influence on aging after the production in the time period evaluated.

Orientador: Tomaz Manabu Hashimoto / Banca: Marcelino Pereira do Nascimento / Banca: Cristina de Carvalho Ares Elisei / Resumo: O presente trabalho estudou as variáveis de fabricação no processo na linha de galvanização contínua por imersão a quente, simulando o processo de conformação e a cura da pintura nas montadoras, visando avaliar as condições de deformação, tempo, temperatura e o envelhecimento desde o tempo de estocagem até a conformação dos aços ultra baixo carbono semi-estabilizado ao Nióbio para obtenção de índices de bake hardening (IBH) satisfatórios, visando o atendimento e a garantia das especificações dos aços BH180 e BH220. Para a execução das análises, utilizou-se o laboratório de controle da qualidade da empresa, onde foram retirados corpos de prova para ensaios de tração e do índice bake hardening seguindo os procedimentos conforme a norma requisitada. O ensaio padrão de bake hardening (BH) consiste em, deformar o corpo de prova até 2%, interromper o ensaio, aquecer o material na estufa por 20 minutos a 170ºC e após resfriamento, dar continuidade ao ensaio. O cálculo do índice de BH foi especificado segundo a norma DIN BS EN 10325. Este trabalho visou a comparação entre dois testes de envelhecimento, um em condição natural e outro artificial. Na condição natural, os corpos de prova foram deixados em temperatura ambiente durante o período de seis meses e, na condição artificial, as variáveis tempo e temperatura foram analisadas. A garantia do tempo de estocagem está sendo discutida entre as montadoras e as usinas. A condição padrão para a simulação do ensaio de aços bake hardening, avaliou a influência de cada variável e verificou que o índice de BH está dentro do especificado em norma, sendo encontrado o valor de 49,0 MPa para o aço BH180 e de 45,0 MPa para o aço BH220. As variáveis mencionadas são importantes para o incremento do índice de BH principalmente a pré-deformação... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This paper studied the variables in the manufacture process in continous hot dipped galvanizing line, simulating the process of drawing and curing of paint in the automakers, to evaluate the conditions of deformation, temperature, time and aging from storage time to drawing of ultra low carbon steel semi-stabilized to achieve a reasonable bake hardening index (BH) in order to find the specifications and warranty BH180 and BH 220 steels. For the application of tests, it was use the quality control laboratory of the company's, where specimens were removed for tensile tests and bake hardening index (BH) following the standard procedures as required. The bake hardening (BH) pattern test consists of deforming the specimen until 2%, stop the test, after heating the material in an oven for 20 minutes at 170 ° C and after air cooling, continue the trial. The calculation of a reasonable bake hardening index (BH) was specified according to DIN BS EN 10325. This study aimed to compare two aging tests, one in natural and the other one in artificial condition. In natural condition, the specimens were left at room temperature for a period of six months, and in artificial condition, time and temperature variables were analyzed. The warranty of the storage time is being discussed between the automakers and steel plants. The default condition for the simulation of the bake hardening steels test, evaluated the influence of each variable and found out that bake hardening index (BH) is within the specified standard, and with values of 49.0 MPa for BH180 steel and 45.0 MPa for BH220 steel. The variables mentioned are important for increasing the bake hardening index (BH) mainly pre-deformation has a significant influence. The steels studied seem not to have great influence on aging after the production in the time period evaluated. / Mestre

Detta är en rapport om svinn av bake-off bröd i butiksledet i Sverige och hur det kan begrän- sas. Vald metod består av två delar. Den första delen är en litteraturstudie om matsvinn. Den andra delen består av intervjuer med en chef på utvald livsmedelsbutik angående svinn av bröd. Orsakerna och åtgärderna jämförs med situationen i den undersökta butiken och åtgär- derna analyseras utifrån tillämpbarhet. Resultatet visar att det finns kundrelaterade och butiks- relaterade orsaker. Kunden förväntar sig ett brett sortiment och välfyllda hyllor. I dagsläget finns en god vetskap om denna typ av problem som påverkas av kunden. Svinn uppstår när den undersökta butiken köper in fel mängd varor. Denna orsak förklarar tydligt vad felet är, vilket inte alltid är fallet med orsaker funna i litteraturstudien. Det är viktigt att analysera hur olika orsaker hänger samman och poängtera den verkliga orsaken till problemet om det ska åtgärdas. Att implementera strikta rutiner för att minska svinn är upp till butiken och förbätt- rar presentationen i butiken. Sådana tillämpbara åtgärder karakteriseras av att vara ekono- miskt fördelaktiga eller att införandet ligger i butikens händer. Butiksansvarig kan informera personalen om ekonomiska och miljömässiga konsekvenser av svinn. Kunderna är däremot omedvetna om att de kan påverka matsvinn redan i butiken och initiativ från högre instanser krävs för att minska denna typ av svinn. / This report highlights the waste of bake-off bread occurring at the store level in Sweden and possible ways of preventing it. The method in the report consists of two parts. Firstly, a litera- ture review of earlier studies on food waste. Secondly, interviews with the manager of a selec- ted grocery store regarding the waste of bread. The causes of food waste, and the measures for reducing it, are compared with the situation in the interviewed store. Furthermore, the measu- res are analyzed based on applicability. The causes either relate to consumers or actions made by the store. Consumers expect the shelves to be fully stocked and products to be widely vari- ed. There is currently a thorough understanding of this sort of problem relating to the consu- mer. Food waste occurs when the store buys the wrong amount of goods. This sentence clear- ly explains what needs to be changed to prevent waste. However, this is not always the case with the causes explained in earlier studies. To prevent food waste, connections between cau- ses must be analyzed and the precise cause of the food waste must be determined. To imple- ment strict routines to reduce waste or not depends solely on the store’s preference. The im- plementation furthermore improves the presentation of the store. These applicable measures to reduce food waste are defined by being profitable or being implementations on the store’s terms. The store manager can inform the staff about the financial and environmental conse- quences of food waste. Consumers, however, are unaware that they can have an impact on food waste already in the store. Therefore, initiatives from higher authorities are necessary to reduce this form of waste.

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Os projetos de carrocerias veiculares atuais procuram desenvolver estruturas leves, seja para reduzir o consumo de combustível, no caso dos motores de combustão interna, seja para maior autonomia de bateria, no caso dos veículos elétricos e híbridos. Redução no consumo de combustível significa redução na emissão de poluentes. As estruturas precisam ser leves, mas cada vez mais resistentes e rígidas a fim de proporcionar máximo conforto e segurança aos ocupantes. Estas premissas têm levado ao contínuo desenvolvimento dos materiais. No caso dos aços, um dos processos que tem permitido a melhora significativa das propriedades mecânicas é a estampagem a quente. Nos últimos anos, as peças estampadas a quente têm ocupado lugar de destaque na estrutura das carrocerias veiculares por estarem em sintonia com as demandas mencionadas. Há muitas pesquisas em curso para esta tecnologia, seja nos materiais, nos meios de produção, nos revestimentos e em aplicações. O aço mais utilizado neste processo, 22MnB5, também apresenta o chamado efeito bake hardening; a tensão de escoamento é aumentada após tratamento térmico realizado em temperaturas próximas a 200 °C. Neste trabalho, visando à melhoria nas propriedades mecânicas, amostras foram tratadas termicamente na faixa de temperatura supracitada. Após isso, dados obtidos de ensaios mecânicos foram inseridos em programas de simulação de impacto lateral cujo resultado foi a redução na intrusão na célula de sobrevivência. O efeito bake hardening também propiciou um aumento na absorção da energia de impacto em teste estático feito com barras de proteção lateral. O mecanismo metalúrgico envolvido no fenômeno, devido à difusão de intersticiais foi evidenciado no ensaio de atrito interno. / The current auto body projects seek to build light structures whose immediate impact is in the reduction in fuel consumption of internal combustion engines or in longer battery life for electric and hybrid vehicles. Reduction in fuel consumption means reduced emissions. The structures need to be lightweight, but increasingly resistant to provide maximum comfort and safety to the occupants. These demands led to the continuous development of new materials. In the case of the steels hot stamping has allowed significant improvement in the mechanical properties. In recent years, hot stamped parts took prominent place in the structure of auto bodies to be in line with the mentioned demands. There are a lot of researches lines for this technology: materials, modes of production, coatings and applications. The most commonly used steel in this process, 22MnB5, also exhibits the bake hardening effect: its yield strength is increased after thermal treatment at temperatures close to 200 °C. To verify this improvement in the mechanical properties, samples were thermally treated. After that, data obtained from mechanical tests were inserted into side-crash simulation programs that resulted in a reduction in intrusion in the passengers compartment. The bake hardening effect also provided an increase in the absorption of the impact energy in a static test done with door beam. The metallurgical mechanism involved in the phenomenon, due to the movement of interstitial was evidenced in the internal friction test.

Os projetos de carrocerias veiculares atuais procuram desenvolver estruturas leves, seja para reduzir o consumo de combustível, no caso dos motores de combustão interna, seja para maior autonomia de bateria, no caso dos veículos elétricos e híbridos. Redução no consumo de combustível significa redução na emissão de poluentes. As estruturas precisam ser leves, mas cada vez mais resistentes e rígidas a fim de proporcionar máximo conforto e segurança aos ocupantes. Estas premissas têm levado ao contínuo desenvolvimento dos materiais. No caso dos aços, um dos processos que tem permitido a melhora significativa das propriedades mecânicas é a estampagem a quente. Nos últimos anos, as peças estampadas a quente têm ocupado lugar de destaque na estrutura das carrocerias veiculares por estarem em sintonia com as demandas mencionadas. Há muitas pesquisas em curso para esta tecnologia, seja nos materiais, nos meios de produção, nos revestimentos e em aplicações. O aço mais utilizado neste processo, 22MnB5, também apresenta o chamado efeito bake hardening; a tensão de escoamento é aumentada após tratamento térmico realizado em temperaturas próximas a 200 °C. Neste trabalho, visando à melhoria nas propriedades mecânicas, amostras foram tratadas termicamente na faixa de temperatura supracitada. Após isso, dados obtidos de ensaios mecânicos foram inseridos em programas de simulação de impacto lateral cujo resultado foi a redução na intrusão na célula de sobrevivência. O efeito bake hardening também propiciou um aumento na absorção da energia de impacto em teste estático feito com barras de proteção lateral. O mecanismo metalúrgico envolvido no fenômeno, devido à difusão de intersticiais foi evidenciado no ensaio de atrito interno. / The current auto body projects seek to build light structures whose immediate impact is in the reduction in fuel consumption of internal combustion engines or in longer battery life for electric and hybrid vehicles. Reduction in fuel consumption means reduced emissions. The structures need to be lightweight, but increasingly resistant to provide maximum comfort and safety to the occupants. These demands led to the continuous development of new materials. In the case of the steels hot stamping has allowed significant improvement in the mechanical properties. In recent years, hot stamped parts took prominent place in the structure of auto bodies to be in line with the mentioned demands. There are a lot of researches lines for this technology: materials, modes of production, coatings and applications. The most commonly used steel in this process, 22MnB5, also exhibits the bake hardening effect: its yield strength is increased after thermal treatment at temperatures close to 200 °C. To verify this improvement in the mechanical properties, samples were thermally treated. After that, data obtained from mechanical tests were inserted into side-crash simulation programs that resulted in a reduction in intrusion in the passengers compartment. The bake hardening effect also provided an increase in the absorption of the impact energy in a static test done with door beam. The metallurgical mechanism involved in the phenomenon, due to the movement of interstitial was evidenced in the internal friction test.

Foundries today use temporary molds made from silica sand with a resin bonding agent to hold a form until the metal is poured. With the aid of computer simulations, the molds are designed to produce good castings with minimal pattern iterations by calculating cooling and porosity. Stress analysis simulations are being developed using the current software, but the known mechanical properties for the sand mold are minimal and incomplete. This study measures the elastic modulus of bonded sand as a function of temperature to obtain baseline data for the model. Following ASTM standards, a three point bend test is used to measure the elastic modulus of chemically bonded sand as a function of temperature to better understand the complex nature of the mold as it undergoes heating and cooling. Multiple measurements of the elastic modulus of PUNB bonded silica sand are performed from room temperature to 500°C in a nitrogen atmosphere to capture the changes in the elastic modulus under heating. It is found that for an intermediate heating rate of 8°C/min, the elastic modulus decreases steeply from a room temperature value of about 3,600 MPa to 600 MPa at 125°C. Between 125°C and 250°C, the elastic modulus is relatively constant. Above 250°C, it increases to 1,200 MPa at 280°C and then decreases again to 800 MPa at 350°C. Above 350°C, the elastic modulus increases linearly with temperature until it reaches 2,200 MPa at 500°C. At approximately 500°C, the strength of the bonded sand vanishes. At a given temperature above 125°C, the elastic modulus can vary by more than a factor of two depending on the heating rate. Furthermore, the elastic modulus agrees with previous steady state temperature measurement literature when specimens are held at a constant temperature until the elastic modulus reach steady. It is also found that the addition of black iron oxide has no effect on the elastic modulus, whereas solvent removal before a test increases the stiffness of the bonded sand at temperatures below 150°C.

The report deals with the experiences and results that arose during the development of the webapplication Bakkassen, a web shop where visitors can order pre-portioned ingredients to bread andpastries. The main objective of the report is to answer a question about how to design a usable andtrustworthy web application. A market plan and a survey was made to determine the target audienceand what features that should be implemented on the web application. The agile work methodologyScrum was used during the development and the work resulted in an easy understandable interfacewith colors chosen with care. The study shows an example of how a usable and trustworthy webapplication can be developed, but because of the limited scope of the study it is hard to draw anygeneral conclusions. / Rapporten behandlar de erfarenheter och resultat som uppkom under utvecklingen avwebbapplikationen Bakkassen, en e-butik där besökaren kan beställa hem portionsförpackadeingredienser till bröd och bakverk. Rapporten syftar till att besvara frågeställningen om hur enanvändbar och förtroendeingivande webbapplikation kan utformas. För att bestämma målgrupp ochvilka funktioner som skulle implementeras gjordes ett förarbete i form av marknadsplan ochenkätundersökning. Utvecklingen följde den agila utvecklingsmetodiken Scrum och resultatet var enwebbapplikationen vars struktur ämnade att underlätta för användaren genom ett lättöverskådligtgränssnitt och färger som valdes med omsorg. Studien visar ett exempel på hur en användbar ochförtroendeingivande webbapplikation kan utvecklas, men några generella slutsatser är svåra att drapå grund av studiens begränsade omfattning.

The automotive manufacturing industry is facing an interesting period of trial when a lot of improvement is expected of them in a short period of time to contribute to a cleaner planet by applying technologies that will reduce fossil fuel consumption. Electrification was good, but this must be accompanied by substantial curb weight reduction, which was provided by alloys such as A365, Aural 5 (AlSi8MnMg), Aural 2 (AlSi10MnMg), and Mercalloy 367 (AlSi9MgMnSr) for making structural parts. The use of these Al alloys is accompanied with extensive heat treatment which on its own involves fossil fuel consumption. In this research, test plates were made utilizing high vacuum high pressure die casting (HVHPDC) and a unique Al-Fe based eutectic alloy with Zn and Mg as precipitation strengtheners. Experimental results demonstrated that they age naturally, with their mechanical properties rising to the industry requirement within three days. DSC experiments carried out at various ages gave further experimental evidence to this natural ageing phenomenon. A portion of the samples was then given an experimental "paint bake" treatment at different ages. This is typical on an assembly line where the coated parts are baked at a temperature range of 120 - 200oC for thirty minutes. It was evidently defensible that samples of various ages respond to the treatment in different ways. The mechanical characteristics of the samples decreased after treatment to same value and progressively increased to match the values of the control samples. During the duration of the experiment, some samples rose quickly while others remained "nearly dead" in the state of low mechanical characteristics or climbed sluggishly to catch up with the natural ageing curve. The poorest results were seen in samples handled at the early stage when the initial clusters are forming indicating that it might not be a good idea to interfere with the NA process at those times. / Thesis / Master of Applied Science (MASc) / Fueled by the desire to produce an Al alloy with good mechanical properties arising from natural ageing, high vacuum high pressure die casting (HVHPDC) was used in making castings of this alloy which contains Fe for improvement on its castability and recyclability, contains Zn and Mg which act as the precipitating strengtheners driving the natural ageing phenomenon. Tests and experiments like uniaxial tensile tests, differential scanning calorimetry and electrical conductivity tests were carried out to ascertain its suitability to be used for structural automotive parts without heat treatment. The results showed that the new Nemalloy HE700 met with the minimum industry requirements for mechanical properties of materials for structural automotive applications within 3 days of natural ageing. The alloy was then subjected to experimental paint bake treatment to observe its reaction to paint bake process and the results were able to show when to do paint bake for best outcome.

Cette étude, réalisée dans le cadre d'une thèse en contrat CIFRE avec la société PSA Peugeot Citroën, a pour objectif l'étude expérimentale et numérique du procédé de sertissage des tôles métalliques. Ce procédé intervient dans les dernières opérations de mise en forme des ouvrants automobiles, après l'emboutissage et le tombage de bord (inclinaison du bord de la pièce à 90◦ ). Il s'agit d'un procédé d'assemblage par déformation plastique à froid, entre la peau extérieure et la doublure (partie renforçante) d'un ouvrant. Il est classiquement scindé en deux étapes, qui sont le présertissage, qui amène le bord tombé à environ 45◦ de la doublure, et le sertissage. Deux matériaux sont étudiés : un aluminium de la série 6000 et un acier à bake hardening. La caractérisation est réalisée à l'aide d'essais de traction uniaxiale et de cisaillement monotone et alterné, an de caractériser l'effet Bauschinger. L'étude s'est particulièrement attachée à la détermination des paramètres matériaux d'une loi de comportement élastoviscoplastique avec des critères de plasticité isotrope et anisotrope couplés à un écrouissage isotrope et mixte. Un dispositif de sertissage spécique a été conçu pour permettre le tombage et le sertissage classique et par roulage d'éprouvettes de laboratoire non planes (galbées) avec des bords courbes. Ces éprouvettes ont subi des prédéformations par expansion biaxiale (2 rayons de galbe différents) puis sont découpées par laser, tombées et serties sur le dispositif. Ces essais ont constitué une base de données expérimentale pour plusieurs géométries, avec mesure des caractéristiques géométriques et des efforts. La modélisation du procédé de sertissage classique a été réalisée avec le logiciel Pamstamp2G afin de déterminer l'influence des lois de comportement (critère de plasticité et type d'écrouissage) sur les résultats de la prédiction numérique. L'étude s'est également orientée sur le développement d'un outil numérique pour modéliser le sertissage par roulage, afin de décrire la trajectoire du galet. La base d'essais a permis la calibration du procédé en déterminant les paramètres numériques optimums à adopter pour cette mise en donnée particulière. La déformation plastique équivalente atteint localement des valeurs entre 0.8 et 1.0 dans la zone pliée et des fissures peuvent apparaître pour l'alliage d'aluminium. Une loi de comportement qui prend en compte l'endommagement ductile (modèle GTN) a été identiée à l'aide d'essais de traction uniaxiale sur éprouvettes droites et avec entailles ainsi que sur des essais d'expansion biaxiale. Des essais expérimentaux représentatifs du procédé de sertissage ont permis de quantier expérimentalement cet endommagement sur la zone pliée et leur modélisation numérique, la détermination de la limite de sertissabilité de la structure.