Nous modélisons la diffusion des atomes interstitiels (C et O) dans des solutions solides (Fe-Cr et Nb-V) et comparons nos résultats aux données expérimentales disponibles dans la littérature. Un ensemble d’énergies de liaisons entre interstitiels et solutés substitutionnels, et de barrières de migration des interstitiels, ont d’abord été calculés en utilisant la théorie de la fonctionnelle de la densité. Des modèles d’interactions de paires ont ensuite été ajustés sur ces données pour calculer les barrières de migration dans n’importe quel environnement chimique local. Ces modèles de paires sont enfin intégrés dans des simulations Monte Carlo cinétiques, afin de modéliser des expériences de diffusion de traceur et de frottement interne. Dans les alliages Fe-Cr-C, les simulations prévoient la formation d’un pic de Snoek unique, dans tout le domaine de composition entre le fer pur et le chrome pur. La barrière de migration moyenne du carbone, donnée par la température de ce pic, augmente progressivement avec la teneur en chrome, l’augmentation étant très faible en dessous de 6% de Cr. Dans les alliages riches en Cr, la barrière de migration moyenne obtenue lors d’une simulation de diffusion de traceur est plus grande que celle obtenue lors d’une simulation de frottement interne. Nous en concluons que la barrière mesurée lors d’une expérience de diffusion de traceur est fortement affectée par le piégeage du carbone dans des environnements riches en fer, qui limite la diffusion à grande distance ; alors que la barrière mesurée par friction interne, qui ne nécessite qu’une diffusion à courte distance, est principalement contrôlée par les barrières de migration des configurations les plus probables. Dans les alliages Nb-V-O dilués, les simulations font apparaitre un pic de Snoek à haute température lorsque la concentration en oxygène est plus faible que celle en vanadium. Quand la concentration en oxygène devient plus importante, un deuxième pic apparait à plus basse température, tandis que le premier pic se déplace vers des températures plus petites. Nous en concluons que le pic à haute température correspond à des paires V-O, et que celui à basse température correspond à la diffusion de l’oxygène dans le niobium pur. Les simulations sont utilisées pour tester le modèle de Koiwa, dans la limite de l’alliage ternaire infiniment dilué. Les deux approches sont en bon accord et nous montrons que la position du pic à haute température n’est pas reliée à une fréquence de saut unique, mais à une fonction complexe de plusieurs fréquences de sauts. Nous présentons enfin les résultats d’une étude préliminaire sur l’effet du carbone sur les cinétiques de séparation de phases dans les alliages fer-chrome irradiés. Nous montrons que la forte attraction entre atomes de carbone et défauts d’irradiation (auto-interstitiels et surtout lacunes) peut dans certaines conditions limiter l’accélération de la précipitation du chrome habituellement provoquée par l’irradiation. / The diffusion of interstitial atoms (C and O) in bcc solid solutions (Fe-Cr and Nb-V) is modelled and compared to experimental data. A set of binding energies and migration barriers for the direct interstitial diffusion mechanism in different local chemical environments are first calculated using Density Functional Theory. Two different pair interaction models are developed in order to reproduce these data and predict the migration barriers in all possible environments. The diffusion models are then implemented in a kinetic Monte Carlo method to simulate tracer diffusion experiments, using a standard procedure, and internal friction experiments, using a novel method. In the Fe-Cr-C systems our internal friction simulations show a unique Snoek peak in the whole concentration range, between pure iron and pure chromium. The average migration enthalpy for C diffusion in Fe-Cr alloys is found to increase progressively with the Cr concentration, with a small rate below 6 %Cr. In Cr-rich alloys, the effective migration barrier for C diffusion is found to be larger in tracer diffusion than in the internal friction simulations. We conclude that the effective migration barrier extracted from tracer diffusion is closely related to trapping effects of C atoms in Fe-rich local environments, whereas the migration barrier associated with internal friction is mainly controlled by the spectrum of migration barriers of the most frequent configurations, as it is clearly shown in the Cr-rich domain. In the dilute Nb-V-O alloys, we find a high temperature Snoek peak when the concentration of oxygen is lower than the vanadium content. But when the oxygen concentration is higher, we see the appearance of a second peak but at a lower temperature and a shift of the first peak to lower temperatures. We conclude that the high temperature peaks correspond to the oxygen-vanadium pairs, and the low temperature peak corresponds to the oxygen Snoek peak in pure Nb. We also use our model in order to validate the Koiwa model in infinitely dilute ternary alloys. Both approaches are in good agreement and we observe that the high temperature peak cannot be directly related to a single jump frequency but to a complex function of them. We also show preliminary results on the effect of C in the precipitation of the Fe-Cr phase separation under irradiation. We observee that a strong attraction between carbon atoms and point defects (vacancies and self-interstitials) might be able to slow down the acceleration of the α’ precipitation.

La presente tesis evalúa el comportamiento mecánico de un suelo arcilloso mezclado con PET triturado. El uso potencial de este material plástico en aplicaciones geotécnicas puede reducir el problema de la eliminación inadecuada y mejorar las características de resistencia y deformación del suelo. Se empleó Tereftalato de polietileno, PET, y suelo arcilloso proveniente de la provincia de Tarapoto. Los parámetros de resistencia al corte que definen las características mecánicas del suelo son el ángulo de fricción y la cohesión. En la ejecución de una obra civil, estos parámetros generalmente no se ajustan a los requerimientos del proyecto, por tal razón se debe buscar una solución para la estabilidad del suelo implicado en cualquier construcción. Esta tesis se realizó en tres etapas, la primera fue la recolección de información, la segunda la fase de laboratorio, llevándose a cabo ensayos de Proctor estándar (densidad – humedad), corte directo (ángulo de fricción y cohesión), limite líquido, limite plástico y granulometría; y por último el análisis de los resultados. El suelo arcilloso utilizado fue mezclado con 5%, 10% y 20% de PET triturado en peso seco. Los porcentajes de PET aumentaron la capacidad de soporte del suelo. / This thesis evaluates the mechanical behavior of a clay soil mixed with crushed PET. The potential use of this waste material in geotechnical applications may ultimately reduce the problem of improper disposal and improve the strength and deformation characteristics of the soil. Polyethylene terephthalate, PET, and clayey soil from the province of Tarapoto were used. The shear strength parameters that define the mechanical properties of soil are the internal friction angle and cohesion. While constructing any civil engineering structure, those parameters usually do not adjust to the requirements of the Project, therefore, there must be a solution for the soil stability in any civil work. This thesis was carried out in three stages, the first was the collection of information, the second the laboratory phase, carrying out standard Proctor tests (density - humidity), direct cutting (angle of friction and cohesion), liquid limit, limit plastic and granulometry; and finally the analysis of the results. The clayey soil used was mixed with 5%, 10% and 20% of crushed PET by dry weight. The percentages of PET increased the soil support capacity. / Tesis

The two main sources of biomass for energy generation are purpose-grown energy crops and waste materials. Energy crops, such as Miscanthus and short rotation woody crops (coppice), are cultivated mainly for energy purposes and are associated with the food vs. fuels debate, which is concerned with whether land should be used for fuel rather than food production. The use of residues from agriculture, such as barley, canola, oat and wheat straw, for energy generation circumvents the food vs. fuel dilemma and adds value to existing crops. In fact, these residues represent an abundant, inexpensive and readily available source of renewable lignocellulosic biomass. In order to reduce industrys operational cost as well as to meet the requirement of raw material for biofuel production, biomass must be processed and handled in an efficient manner. Due to its high moisture content, irregular shape and size, and low bulk density, biomass is very difficult to handle, transport, store, and utilize in its original form. Densification of biomass into durable compacts is an effective solution to these problems and it can reduce material waste. Upon densification, many agricultural biomass materials, especially those from straw and stover, result in a poorly formed pellets or compacts that are more often dusty, difficult to handle and costly to manufacture. This is caused by lack of complete understanding on the natural binding characteristics of the components that make up biomass. An integrated approach to postharvest processing (chopping, grinding and steam explosion), and feasibility study on lab-scale and pilot scale densification of non-treated and steam exploded barley, canola, oat and wheat straw was successfully established to develop baseline data and correlations, that assisted in performing overall specific energy analysis. A new procedure was developed to rapidly characterize the lignocellulosic composition of agricultural biomass using the Fourier Transform Infrared (FTIR) spectroscopy. In addition, baseline knowledge was created to determine the physical and frictional properties of non-treated and steam exploded agricultural biomass grinds. Particle size reduction of agricultural biomass was performed to increase the total surface area, pore size of the material and the number of contact points for inter-particle bonding in the compaction process. Predictive regression equations having higher R2 values were developed that could be used by biorefineries to perform economic feasibility of establishing a processing plant. Specific energy required by a hammer mill to grind non-treated and steam exploded barley, canola, oat and wheat straw showed a negative power correlation with hammer mill screen sizes. Rapid and cost effective quantification of lignocellulosic components (cellulose, hemicelluloses and lignin) of agricultural biomass (barley, canola, oat and wheat) is essential to determine the effect of various pre-treatments (such as steam explosion) on biomass used as feedstock for the biofuel industry. A novel procedure to quantitatively predict lignocellulosic components of non-treated and steam exploded barley, canola, oat and wheat straw was developed using Fourier Transformed Infrared (FTIR) spectroscopy. Regression equations having R2 values of 0.89, 0.99 and 0.98 were developed to predict the cellulose, hemicelluloses and lignin compounds of biomass, respectively. The average absolute difference in predicted and measured cellulose, hemicellulose and lignin in agricultural biomass was 7.5%, 2.5%, and 3.8%, respectively. Application of steam explosion pre-treatment on agricultural straw significantly altered the physical and frictional properties, which has direct significance on designing new and modifying existing bins, hoppers and feeders for handling and storage of straw for biofuel industry. As a result, regression equations were developed to enhance process efficiency by eliminating the need for experimental procedure while designing and manufacturing of new handling equipment. Compaction of low bulk density agricultural biomass is a critical and desirable operation for sustainable and economic availability of feedstock for the biofuel industry. A comprehensive study of the compression characteristics (density of pellet and total specific energy required for compression) of ground non-treated and steam exploded barley, canola, oat and wheat straw obtained from three hammer mill screen sizes of 6.4, 3.2 and 1.6 mm at 10% moisture content (wb) was conducted. Four preset pressures of 31.6, 63.2, 94.7 and 138.9 MPa, were applied using an Instron testing machine to compress samples in a cylindrical die. It was determined that the applied pressure (60.4%) was the most significant factor affecting pellet density followed by the application of steam explosion pre-treatment (39.4%). Similarly, the type of biomass (47.1%) is the most significant factor affecting durability followed by the application of pre-treatment (38.2%) and grind size (14.6%). Also, the applied pressure (58.3%) was the most significant factor affecting specific energy required to manufacture pellets followed by the biomass (15.3%), pre-treatment (13.3%) and grind size (13.2%), which had lower but similar effect affect on specific energy. In addition, correlations for pellet density and specific energy with applied pressure and hammer mill screen sizes having highest R2 values were developed. Higher grind sizes and lower applied pressures resulted in higher relaxations (lower pellet densities) during storage of pellets. Three compression models, namely: Jones model, Cooper-Eaton model, and Kawakita-Ludde model were considered to determine the pressure-volume and pressure-density relationship of non-treated and steam exploded straws. Kawakita-Ludde model provided the best fit to the experimental data having R2 values of 0.99 for non-treated straw and 1.00 for steam exploded biomass samples. The steam exploded straw had higher porosity than non-treated straw. In addition, the steam exploded straw was easier to compress since it had lower yield strength or failure stress values compared to non-treated straw. Pilot scale pelleting experiments were performed on non-treated, steam exploded and customized (adding steam exploded straw grinds in increments of 25% to non-treated straw) barley, canola, oat and wheat straw grinds obtained from 6.4, 3.2, 1.6 and 0.8 mm hammer mill screen sizes at 10% moisture content (wb). The pilot scale pellet mill produced pellets from ground non-treated straw at hammer mill screen sizes of 0.8 and 1.6 mm and customized samples having 25% steam exploded straw at 0.8 mm. It was observed that the pellet bulk density and particle density are positively correlated. The density and durability of agricultural straw pellets significantly increased with a decrease in hammer mill screen size from 1.6 mm to 0.8 mm. Interestingly, customization of agricultural straw by adding 25% of steam exploded straw by weight resulted in higher durability (> 80%) pellets but did not improve durability compared to non-treated straw pellets. In addition, durability of pellets was negatively correlated to pellet mill throughput and was positively correlated to specific energy consumption. Total specific energy required to form pellets increased with a decrease in hammer mill screen size from 1.6 to 0.8 mm and also the total specific energy significantly increased with customization of straw at 0.8 mm screen size. It has been determined that the net specific energy available for production of biofuel is a significant portion of original agricultural biomass energy (89-94%) for all agricultural biomass.

The two main sources of biomass for energy generation are purpose-grown energy crops and waste materials. Energy crops, such as Miscanthus and short rotation woody crops (coppice), are cultivated mainly for energy purposes and are associated with the food vs. fuels debate, which is concerned with whether land should be used for fuel rather than food production. The use of residues from agriculture, such as barley, canola, oat and wheat straw, for energy generation circumvents the food vs. fuel dilemma and adds value to existing crops. In fact, these residues represent an abundant, inexpensive and readily available source of renewable lignocellulosic biomass. In order to reduce industrys operational cost as well as to meet the requirement of raw material for biofuel production, biomass must be processed and handled in an efficient manner. Due to its high moisture content, irregular shape and size, and low bulk density, biomass is very difficult to handle, transport, store, and utilize in its original form. Densification of biomass into durable compacts is an effective solution to these problems and it can reduce material waste. Upon densification, many agricultural biomass materials, especially those from straw and stover, result in a poorly formed pellets or compacts that are more often dusty, difficult to handle and costly to manufacture. This is caused by lack of complete understanding on the natural binding characteristics of the components that make up biomass. An integrated approach to postharvest processing (chopping, grinding and steam explosion), and feasibility study on lab-scale and pilot scale densification of non-treated and steam exploded barley, canola, oat and wheat straw was successfully established to develop baseline data and correlations, that assisted in performing overall specific energy analysis. A new procedure was developed to rapidly characterize the lignocellulosic composition of agricultural biomass using the Fourier Transform Infrared (FTIR) spectroscopy. In addition, baseline knowledge was created to determine the physical and frictional properties of non-treated and steam exploded agricultural biomass grinds. Particle size reduction of agricultural biomass was performed to increase the total surface area, pore size of the material and the number of contact points for inter-particle bonding in the compaction process. Predictive regression equations having higher R2 values were developed that could be used by biorefineries to perform economic feasibility of establishing a processing plant. Specific energy required by a hammer mill to grind non-treated and steam exploded barley, canola, oat and wheat straw showed a negative power correlation with hammer mill screen sizes. Rapid and cost effective quantification of lignocellulosic components (cellulose, hemicelluloses and lignin) of agricultural biomass (barley, canola, oat and wheat) is essential to determine the effect of various pre-treatments (such as steam explosion) on biomass used as feedstock for the biofuel industry. A novel procedure to quantitatively predict lignocellulosic components of non-treated and steam exploded barley, canola, oat and wheat straw was developed using Fourier Transformed Infrared (FTIR) spectroscopy. Regression equations having R2 values of 0.89, 0.99 and 0.98 were developed to predict the cellulose, hemicelluloses and lignin compounds of biomass, respectively. The average absolute difference in predicted and measured cellulose, hemicellulose and lignin in agricultural biomass was 7.5%, 2.5%, and 3.8%, respectively. Application of steam explosion pre-treatment on agricultural straw significantly altered the physical and frictional properties, which has direct significance on designing new and modifying existing bins, hoppers and feeders for handling and storage of straw for biofuel industry. As a result, regression equations were developed to enhance process efficiency by eliminating the need for experimental procedure while designing and manufacturing of new handling equipment. Compaction of low bulk density agricultural biomass is a critical and desirable operation for sustainable and economic availability of feedstock for the biofuel industry. A comprehensive study of the compression characteristics (density of pellet and total specific energy required for compression) of ground non-treated and steam exploded barley, canola, oat and wheat straw obtained from three hammer mill screen sizes of 6.4, 3.2 and 1.6 mm at 10% moisture content (wb) was conducted. Four preset pressures of 31.6, 63.2, 94.7 and 138.9 MPa, were applied using an Instron testing machine to compress samples in a cylindrical die. It was determined that the applied pressure (60.4%) was the most significant factor affecting pellet density followed by the application of steam explosion pre-treatment (39.4%). Similarly, the type of biomass (47.1%) is the most significant factor affecting durability followed by the application of pre-treatment (38.2%) and grind size (14.6%). Also, the applied pressure (58.3%) was the most significant factor affecting specific energy required to manufacture pellets followed by the biomass (15.3%), pre-treatment (13.3%) and grind size (13.2%), which had lower but similar effect affect on specific energy. In addition, correlations for pellet density and specific energy with applied pressure and hammer mill screen sizes having highest R2 values were developed. Higher grind sizes and lower applied pressures resulted in higher relaxations (lower pellet densities) during storage of pellets. Three compression models, namely: Jones model, Cooper-Eaton model, and Kawakita-Ludde model were considered to determine the pressure-volume and pressure-density relationship of non-treated and steam exploded straws. Kawakita-Ludde model provided the best fit to the experimental data having R2 values of 0.99 for non-treated straw and 1.00 for steam exploded biomass samples. The steam exploded straw had higher porosity than non-treated straw. In addition, the steam exploded straw was easier to compress since it had lower yield strength or failure stress values compared to non-treated straw. Pilot scale pelleting experiments were performed on non-treated, steam exploded and customized (adding steam exploded straw grinds in increments of 25% to non-treated straw) barley, canola, oat and wheat straw grinds obtained from 6.4, 3.2, 1.6 and 0.8 mm hammer mill screen sizes at 10% moisture content (wb). The pilot scale pellet mill produced pellets from ground non-treated straw at hammer mill screen sizes of 0.8 and 1.6 mm and customized samples having 25% steam exploded straw at 0.8 mm. It was observed that the pellet bulk density and particle density are positively correlated. The density and durability of agricultural straw pellets significantly increased with a decrease in hammer mill screen size from 1.6 mm to 0.8 mm. Interestingly, customization of agricultural straw by adding 25% of steam exploded straw by weight resulted in higher durability (> 80%) pellets but did not improve durability compared to non-treated straw pellets. In addition, durability of pellets was negatively correlated to pellet mill throughput and was positively correlated to specific energy consumption. Total specific energy required to form pellets increased with a decrease in hammer mill screen size from 1.6 to 0.8 mm and also the total specific energy significantly increased with customization of straw at 0.8 mm screen size. It has been determined that the net specific energy available for production of biofuel is a significant portion of original agricultural biomass energy (89-94%) for all agricultural biomass.

Past studies on sands have shown that the shear strength measured in plane strain tests was higher than that measured in triaxial tests. It was observed that this difference changed with the friction angle &amp / #966 / cv at constant volume related to the mineralogical composition. In order to investigate the difference in strength measured in the wedge shear test, which approaches the plane strain condition, in the triaxial test, and in the shear box test, Anatolian sands were obtained from different locations in Turkey. Mineralogical analyses, identification tests, wedge shear tests (cylindrical wedge shear tests (cylwests) and prismatic wedge shear tests (priswests)), triaxial tests, and shear box tests were performed on these samples. In all shear tests, the shear strength measured was found to increase with the inclination &amp / #948 / of the shear plane to the bedding planes. Thus, cylwests (&amp / #948 / = 60o) iii yielded higher values of internal friction &amp / #966 / by about 3.6o than priswests (&amp / #948 / = 30o) under normal stresses between 17 kPa and 59 kPa. Values of &amp / #966 / measured in cylwests were about 1.08 times those measured in triaxial tests (&amp / #948 / &amp / #8776 / 65o), a figure close to the corresponding ratio of 1.13 found by past researchers between actual plane strain and triaxial test results. There was some indication that the difference between cylwest and triaxial test results increased with the &amp / #966 / cv value of the samples. With the smaller &amp / #948 / values (30o and 40o), priswests yielded nearly the same &amp / #966 / values as those obtained in triaxial tests under normal stresses between 20 kPa and 356 kPa. Shear box tests (&amp / #948 / =0o) yielded lower values of &amp / #966 / than cylwests (by about 7.9o), priswests (by about 4.4o), and triaxial tests (by about 4.2o) under normal stresses between 17 kPa and 48 kPa. It was shown that the shear strength measured in shear box tests showed an increase when &amp / #948 / was increased from 30o to 60o / this increase (about 4.2o) was of the order of the difference (about 3.6o) between priswest (&amp / #948 / = 30o) and cylwest (&amp / #948 / = 60o) results mentioned earlier. Shear box specimens with &amp / #948 / = 60o, prepared from the same batch of any sample as the corresponding cylwests, yielded &amp / #966 / values very close to those obtained in cylwests.

Diploma thesis describes design and function verification of device for filling tap hole of electric arc furnace with tap hole diameter from 190 mm to 250 mm. The theses includes drive design calculation of chute swinging movement and bearing calculations. Another part of the thesis deals with verification of device functions which it is completed with process description of creating DEM simulation in program YADE. The thesis also includes basic experiments for determination angle of internal friction, angle of repose, coefficient of restitution and angle of material friction on a steel surface. Drawing documentation of selected assemblies is part of the thesis.

Introduktion – En fråga har väckts kring hur jordtryck beräknas enligt en klassiskjordtryckteori som beskrivs i läroböcker så som (Sällfors,2009), Trafikverket krav och Eurocode av företaget Vara byggkonsult AB. För att skapa en bättre förståelse så togett praktiskt test fram för att mäta jordtrycket utifrån klassiska teorier och jämförs med dessa.Metod – Den valda forskningsmetoden är en litteraturstudie och ett experimentellkvantitativ test. Framtagandet av testet är en iterativ process där metod och utformande uppdaterats efter observationer och diskussion.Resultat – Beräknade värden för den aktiva jordtryckskoefficienten med de olika metoderna varierar mellan 0,221 - 0,278 för materialet 0–4 och mellan 0,25 - 0,334 för materialet 8-16 beroende på vilken metod som avvänds. För de uppmätta värdena så varierar dessa från 0,173 - 0,279 för materialet 0–4 och 0,227 – 0,296 för materialet 8–16 beroende på vilken last som tillförts. Att värdena varierar beror på faktorer så sominre friktionsvinkel, friktion mellan stödvägg och material, beräkningsmetod, samt vilken last som använts vid utfört test.Analys – Genom att jämföra beräkningsmetoderna med de uppmätta testvärdena går det att se likheter och skillnader mellan resultaten. För materialet 0–4 går det att se en likhet mellan de beräknade värdena och de uppmätta värdena för de beräkningsmetoder där friktionen antas vara 0. För materialet 8–16 är det uppmätta värdet konstant lägre än de beräknade för alla beräkningsmetoder. För båda materialtyperna går det att se en trend där ökningen i det uppmätta värdet minskar ju högre last som läggs på.En analys utifrån frågeställning två har gjorts där modellen och metoden för utförandet av det praktiska testet analyserats. De resultat som producerats ur modellen är trovärdiga och är upprepbara till hög grad. Modellen har konstruerats med material och verktyg tillgängliga i en vanlig bygghandel. Materiallista samt ritning på konstruktionen har dokumenterats samt att metoden för genomförande av testerna är väl dokumenterad.Utifrån en analys av fraktionsstorlekens påverkan på det uppmätta trycket observeras det att ett finkornigt material som 0–4 kan uppnå ett högre tryck än ett grövre material som 8–16. De utförda testen stödjer detta då materialet 0–4 resulterar i en högre jordtryckskoefficient än materialet 8–16. Detta är dock motsägelsefullt till hur klassiskt sett så sker det en ökning i friktionsvinkel desto större fraktionsstorleken är.Diskussion – Trafikverkets metod att beräkna jordtryckskofficienten anses vara smidigare att använda i jämförelse med Eruocdes sätt, då det inte krävs mer än ett uppskattande av materialets egenskaper.Faktorer så som mänskliga faktorn är något som också tas upp i rapporten som har haft en inverkan på det slutgiltiga resultatet samt utförandet av tester. Att rita upp en modell digitalt med perfekta linjer är en sak, men att bygga ihop den i verkligheten är en annan sak. För att motverka faktorer så som mänskliga faktorn, så har en rad olika förändringar gjort på modellen samt utförandet av testerna. Enligt de resultat som framtagits så syns det att det finns en skillnad mellan de olika materialen, men detta är inte en stor skillnad. Friktionsvinklarna för materialen skiljer ivsig inte med många grader och därför har inte heller en stor kraftskillnad kunnat uppmätas.Då grundkunskapen vid undersökningens start inte var speciellt hög så lede det tillmisstag som kunde undvikits. Den tid som lagts ner på att fixa de misstagen kunde istället lagts ner på att förbättra modellen för att få ännu bättre värden. / Introduction – A question has been raised regarding how earth pressure is being calculated regarding classical textbook theory, the Swedish Transport Administration and Eurocode by the company Vara byggkonsult AB. To create a better understanding of the subject a practical test is being derived from classical theories and compared to these.Method – The chosen research method is a litterature study and an experimental quantitative test. To produce a test an iterative process is being used that is beeing updated according to observations and discussions.Results – Calculated values for the active earth pressure coefficient with the different methods vary between 0,221 – 0,278 for the material 0-4 and between 0,25 – 0,334 for the material 8-16 depending on which method is used. For the measured values, these vary from 0,173 – 0,279 for the material 0-4 and 0,227 – 0,296 for the material 8-16, depending on the load added. The fact that the values vary depends on factors such as internal friction angle, friction between the supporting wall and material, calculation method and which load was used when the test was carries out.Analysis – By comparing the calculation methods with the measured test values, it is possible to see similarities and differences between the results. For the material 0-4, it is possible to see a similarity between the calculated values for the calculation methods where the friction is assumed to be 0. For the material 8-16, the measured value is constantly lower than the calculated values for all calculation methods. For both material types, a trend can be seen where the increase in the measured value decreases the higher the load that is applied. An analysis based on question two has been done where the model and method for preforming the practical test has been analysed. The results produced from the model are credible and are repeatable to a high degree. The model has been constructed with materials and tools available in a regular hardware store. Material list and drawing of the construction have been documented and that the method for carrying out the tests is well documented.Based on an analysis of the effect of fraction size on the measured pressure, it is observed that a fine-grained material such as 0–4 can achieve a higher pressure than a coarser material such as 8–16. The tests carried out support this as material 0–4 results in a higher earth pressure coefficient than material 8–16. However, this is contradictory to how, classically speaking, there is an increase in friction angle the larger the fraction size is.Discussion – The Swedish Transport Administration's method of calculating the earth pressure coefficient is considered easier to use in comparison to Eruocde's method, as no more than an estimation of the material's properties is required.Factors such as the human factor is something that is also addressed in the report that has had an impact on the final result as well as the execution of tests. Drawing up a model digitally with perfect lines is one thing, but building it in real life is another. To counteract factors such as the human factor, a number of different changes have been made to the model and the execution of the tests.According to the results produced, it appears that there is a difference between the different materials, but this is not a big difference. The friction angles of the materials iido not differ by many degrees and therefore a large force difference has not been measured either.As the basic knowledge at the start of the survey was not particularly high, it led to mistakes that could have been avoided. The time spent on fixing those mistakes could instead be spent on improving the model to get even better values.

Submitted by Pedro Silva Filho (pfsilva@ipen.br) on 2017-11-21T11:35:55Z No. of bitstreams: 0 / Made available in DSpace on 2017-11-21T11:35:56Z (GMT). No. of bitstreams: 0 / 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. / Tese (Doutorado em Tecnologia Nuclear) / IPEN/T / Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP