The objective of this project is about a kinematic analysis of a shear zone, specifically a graben structure. The surface of the study area has also been investigated, this is to understand if a faulting reactivation has occurred due to glacial impact. The graben structure is exposed along a road cut, next to the E18 highway at Ekolsund, 14km east of Enköping. The results of the report are based on field studies of the geometrical relationship pattern of fracture planes, relative displacement along fracture and a kinematic analysis of movements along fractures. A high resolution terrain model was acquired in the analyzing of the graben structure formation and to create a geometrical 3D brittle deformation model. This model was applied to reconstruct the deformation process. The area contains a more than 1,1km long dextral NE-trending strike-slip fault feature in a polydeformed Precambrian bedrock. The fault is connected NE to one of the regional structure that delimits the bedrock blocks. The fault is visible both as a topographical feature from the ground and from aerial photos. While the project followed through it was clear that the area had been subjected to reactivation. The evidence for this claim stems from an observed semivertical fracture plane with conjugating subhorizontal striations markers that contain an alternating plunge and trend. Other evidence for a reactivation scenario is the fault gouges that contain horizontal striation as well as steep plunging striation, indicating a dip-slip faulting movement. The main zone of faulting displays lower altitude than the surrounding rock. This indicates an asymmetric graben structure that has been subjected to polydeformation. When analyzing the results, it is concluded that a pull-apart basin event has occurred. It’s highly possibly that it has been undergoing modifications during its geological history, resulting in a polydeformed reactivation of the minor faults outlining the graben structure. / Syftet med denna studie är att utföra en kinematisk analys av en förkastningszon, speciellt där en mindre graben struktur utbildats. Ytan för det studerade området är även det viktigt, det är för att förstå ifall en förkastningsreaktivering har skett i och med en glacial påverkan. Graben strukturen är blottad längs en vägskärning, utmed E18 vid Ekolsund, 14km österut om Enköping. Resultatet av rapporten är baserat på fältstudier med fokus på geometriska relationsmönster hos sprickplan, relativa förskjutningar längs sprickor och en kinematisk analys av rörelser längs sprickor. En högupplöst terrängmodell var erhållen vid analys av grabenstrukturens formation och för att skapa en 3D sprödtektonisk deformationsmodell. Modellen var tillämpad vid rekonstruering av deformationsprocessen. Området innefattar en mer än 1,1km lång dextral NO-orienterad strike-slip förkastning i en polydeformerad Prekambrisk berggrund. Förkastningen är ansluten NO till en av de regionala strukturerna som begränsar berggrundsblocken. Förkastningen är synlig både på marknivå och från flygfoton. Medan projektet fortlöpte blev det tydligare att området blivit utsatt för en reaktivering. Beläggen för detta påstående grundar sig i de observerade semi-vertikala sprickplanen med konjugerande subhorisontala striationer som har alternerande stupning och trend. Andra belägg för ett reaktiveringsscenario är de fault gouge strukturerna som innehåller horisontala striationer såväl som stupande striationer, vilket indikerar på en dip-slip förkastningsrörelse. Huvudzonen av förkastningen uppvisar lägre altitud än kringliggande bergyta. Det här indikerar en asymmetrisk graben struktur som har utsatts för polydeformation. Vid analys av resultatet, så kan det sammanfattas att en pull-apart basin förkastning har inträffat. Däremot är det mycket möjligt att zonen har undergått fler modifikationer under dess geologiska historia, vilket har resulterat i en polydeformerad reaktivering av mindre förkastningar som gett kontur dragen åt graben strukturen.

Alumina is one of the most commonly used engineering ceramics for a variety of applications ranging from microelectronics to prosthetics due to its desirable properties. Unfortunately, conventional machining techniques generally lead to fracture, tool failure, low surface integrity, high energy consumption, low material removal rate, and high tool wear during machining due to high hardness and brittleness of the ceramic material. Laser machining offers an alternative for rapid processing of brittle and hard engineering ceramics. However, the material properties, especially the high thermal expansion coefficient and low thermal conductivity, may cause ceramic fracture due to thermal damage. Striation formation is another defect in laser cutting. These drawbacks limit advanced ceramics in engineering applications. In this work, various lasers and machining techniques are investigated to explore the feasibility of high-quality laser machining different thicknesses of alumina. The main contributions include: (i) Fibre laser crack-free cutting of thick-section alumina (up to 6-mm-thickness). A three-dimensional numerical model considering the material removal was developed to study the effects of process parameters on temperature, thermal-stress distribution, fracture initiation and propagation in laser cutting. A rapid parameters optimisation procedure for crack-free cutting of thick-section ceramics was proposed. (ii) Low power CW CO2 laser underwater machining of closed cavities (up to 2-mm depth) in alumina was demonstrated with high-quality in terms of surface finish and integrity. A three-dimensional thermal-stress model and a two-dimensional fluid smooth particle hydrodynamic model (SPH) were developed to investigate the physical processes during CO2 laser underwater machining. SPH modelling has been applied for the first time to studying laser processing of ceramics. (iii) Striation-free cutting of alumina sheets (1-mm thickness) is realised using a nano-second pulsed DPSS Nd: YAG laser, which demonstrates the capability of high average power short pulsed lasers in high-quality macro-machining. A mechanism of pulsed laser striation-free cutting was also proposed. The present work opens up new opportunities for applying lasers for high-quality machining of engineering ceramics.

No description available.

Este trabalho visa determinar a razão de carga cíclica R através da medida, na superficie de fratura, da relação entre a largura inter-estrias (s) e a altura da estria (H). É de conhecimento que o espaçamento (s) se correlaciona com a taxa de crescimento da trinca da/dN, enquanto que a curva da/dN x &#916K depende da razão de carga R. Para esta avaliação, corpos de prova do tipo compacto C(T) foram extraídos na orientação LT do centro de uma placa laminada da liga de alumínio SAE-AMS 7475 T7351 para realização dos ensaios de propagação de trinca por fadiga. Estes ensaios foram realizados de duas formas diferentes. A primeira, para obtenção de dados relativos à região II da curva da/dN x &#916K, sendo, neste caso, utilizadas quatro diferentes razões de carga (R=O,1; R=0,3; R=0,5; R=0,7). No outro caso, os ensaios de fadiga foram realizados sob &#916K constante e utilizados os mesmos quatro níveis de razão de carregamento R para determinação da curva da/dN x &#916K constante. Os níveis de &#916K aplicados foram tomados na região de Paris da curva da/dN x &#916K. A análise fratográfica por microscopia eletrônica foi conduzida nas superfícies dos corpos de prova do ensaio de fadiga com &#916K constante. Isto foi feito para determinar os espaçamentos inter-estria (s) e a altura H das estrias para cada nível de &#916K aplicado. Observou-se que a taxa de crescimento da trinca (da/dN) e o espaçamento inter-estrias (s) sofrem influência direta com a variação do fator de intensidade de tensão (&#916K), entretanto, observou-se, também, que a relação de proporcionalidade de 1:1 entre eles somente é válida para níveis de da/dN variando entre 0,1 a 1 &#956/ciclo. Os valores da morfologia da estrias (H/s) sofrem influência significativa com o aumento da razão de carga R, entretanto, ficou evidenciado que o fator de intensidade de tensão máxima Kmáx. não tem influência nesta relação. Evidenciou-se que a largura da estria corresponde à taxa de crescimento da trinca (da/dN), e que a relação entre a altura e o espaçamento da estria (H/s) possui uma correspondência direta com a razão de carga R, que tem influência significativa sobre a propagação de trinca por fadiga. / This work aims at to method to determine the load ratio R through of measure, on the fractured of surfaces the relation between the width striation spacing (s) and the height of the striation (H). It is of knowledge that the spacing (s), if correlates with the fatigue crack growth rates da/dN, whereas the curve da/dN x &#916K depends on the load ratio R. For this evaluation compact tension C(T) specimens had been extracted in the L- T orientation of a laminate plate of the aluminum alloy SAE-AMS 7475 T7351.These test had been carried out of two different forms. The first one, for attainment of relative data to region II of the curve da/dN x &#916K, being, in this in case that used four different load ratios (R=O,1; R=0,3; R=0,5; R=0,7). In the other in case that, the fatigue crack growth rates had been carried out under &#916K constant and used same the four levels of load ratios R for determination of the curve of constant da/dN x &#916K. The applied levels of &#916K had been taken in the region II of the curve da/dN x &#916K. The fractographic analysis for electronic microscopy was lead on the surfaces of the specimens tested in fatigue with constant &#916K. This was made to determine the striation spacing (s) and height (H) of the striations for each constant level of &#916K. It was observed that the fatigue crack growth rates (da/dN) and the striation spacing (s) suffers direct influence with the variation of &#916K. Also, was observed that the relation of proportionality of 1:1 between them is only valid for levels of da/dN in the range of 0,1 to 1,0 mm/cycle. The values of the relationship of the striation dimensions (H/s) suffer significant influence with the increasing of load ratios R. However, were evidenced that the value of Kmax. does not have influence in this relationship. It was found that the width of the striation corresponds to the value of (da/dN) and that the relation between the height and the striation of spacing (H/s) had a direct correspondence with the load ratios R that has signifficant effect on the fatigue crack growth rates.

Este trabalho visa determinar a razão de carga cíclica R através da medida, na superficie de fratura, da relação entre a largura inter-estrias (s) e a altura da estria (H). É de conhecimento que o espaçamento (s) se correlaciona com a taxa de crescimento da trinca da/dN, enquanto que a curva da/dN x &#916K depende da razão de carga R. Para esta avaliação, corpos de prova do tipo compacto C(T) foram extraídos na orientação LT do centro de uma placa laminada da liga de alumínio SAE-AMS 7475 T7351 para realização dos ensaios de propagação de trinca por fadiga. Estes ensaios foram realizados de duas formas diferentes. A primeira, para obtenção de dados relativos à região II da curva da/dN x &#916K, sendo, neste caso, utilizadas quatro diferentes razões de carga (R=O,1; R=0,3; R=0,5; R=0,7). No outro caso, os ensaios de fadiga foram realizados sob &#916K constante e utilizados os mesmos quatro níveis de razão de carregamento R para determinação da curva da/dN x &#916K constante. Os níveis de &#916K aplicados foram tomados na região de Paris da curva da/dN x &#916K. A análise fratográfica por microscopia eletrônica foi conduzida nas superfícies dos corpos de prova do ensaio de fadiga com &#916K constante. Isto foi feito para determinar os espaçamentos inter-estria (s) e a altura H das estrias para cada nível de &#916K aplicado. Observou-se que a taxa de crescimento da trinca (da/dN) e o espaçamento inter-estrias (s) sofrem influência direta com a variação do fator de intensidade de tensão (&#916K), entretanto, observou-se, também, que a relação de proporcionalidade de 1:1 entre eles somente é válida para níveis de da/dN variando entre 0,1 a 1 &#956/ciclo. Os valores da morfologia da estrias (H/s) sofrem influência significativa com o aumento da razão de carga R, entretanto, ficou evidenciado que o fator de intensidade de tensão máxima Kmáx. não tem influência nesta relação. Evidenciou-se que a largura da estria corresponde à taxa de crescimento da trinca (da/dN), e que a relação entre a altura e o espaçamento da estria (H/s) possui uma correspondência direta com a razão de carga R, que tem influência significativa sobre a propagação de trinca por fadiga. / This work aims at to method to determine the load ratio R through of measure, on the fractured of surfaces the relation between the width striation spacing (s) and the height of the striation (H). It is of knowledge that the spacing (s), if correlates with the fatigue crack growth rates da/dN, whereas the curve da/dN x &#916K depends on the load ratio R. For this evaluation compact tension C(T) specimens had been extracted in the L- T orientation of a laminate plate of the aluminum alloy SAE-AMS 7475 T7351.These test had been carried out of two different forms. The first one, for attainment of relative data to region II of the curve da/dN x &#916K, being, in this in case that used four different load ratios (R=O,1; R=0,3; R=0,5; R=0,7). In the other in case that, the fatigue crack growth rates had been carried out under &#916K constant and used same the four levels of load ratios R for determination of the curve of constant da/dN x &#916K. The applied levels of &#916K had been taken in the region II of the curve da/dN x &#916K. The fractographic analysis for electronic microscopy was lead on the surfaces of the specimens tested in fatigue with constant &#916K. This was made to determine the striation spacing (s) and height (H) of the striations for each constant level of &#916K. It was observed that the fatigue crack growth rates (da/dN) and the striation spacing (s) suffers direct influence with the variation of &#916K. Also, was observed that the relation of proportionality of 1:1 between them is only valid for levels of da/dN in the range of 0,1 to 1,0 mm/cycle. The values of the relationship of the striation dimensions (H/s) suffer significant influence with the increasing of load ratios R. However, were evidenced that the value of Kmax. does not have influence in this relationship. It was found that the width of the striation corresponds to the value of (da/dN) and that the relation between the height and the striation of spacing (H/s) had a direct correspondence with the load ratios R that has signifficant effect on the fatigue crack growth rates.

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

No description available.

Although a number of definitions of mixing have been proposed in the literature, no single definition accurately and clearly describes the full range of problems in the field of industrial mixing. Based on the review of mixing and segregation characterization techniques in chemical engineering, spatial statistics and population studies, a definition of industrial mixing is proposed in this thesis, based on three separate dimensions of segregation. The first dimension is the intensity of segregation which quantifies the uniformity of concentration; the second dimension is the scale of segregation or clustering; and the last dimension is the exposure or the potential to reduce segregation. The first dimension focuses on the instantaneous concentration variance; the second on the instantaneous length scales in the mixing field; and the third on the driving force for change, i.e. the mixing time scale, or the instantaneous rate of reduction in segregation. The definition is introduced using concepts, theory and mathematical equations. This definition provides a theoretical framework for the rigorous analysis of mixing problems, encompassing all industrial mixing processes and allowing a clear evaluation of experimental methods. In this work, the three dimensions of segregation are presented and defined in the context of previous definitions of mixing, and then applied to a range of industrial mixing problems to test their accuracy and robustness. Suitable quantities for direct measurement of the dimensions of segregation are then investigated in detail. The result is a toolkit of ready-to-use methods for the measurement of the intensity (CoV) and the scale of segregation (maximum striation thickness on a transect, point-to-nearest neighbour distributions and variogram), provided as Matlab codes. The chosen methods are thoroughly investigated by testing their applicability, limitations, sampling strategies and meaningfulness of the results using selected sets of mixing data, resulting in creation of guidelines for the use of each of the provided methods. The developed definition of mixing, together with tools and guidelines for measurement of mixing will help researches to further develop the field of mixing, engineers to solve practical industrial mixing problems, and instructors of chemical engineering courses to introduce mixing concepts more easily. / Chemical Engineering

Este trabalho discutiu a relação entre o espaçamento inter-estrias , isto é, a taxa de propagação da trinca microscópica SL (local) e SP (projetada) e a taxa de propagação macroscópica , da/dN, obtido após o ensaio de propagação de trinca por fadiga. Corpos de prova compacto C(T) foram extraídos na orientação LT do centro de uma placa laminada de liga de alumínio SAE-AMS 7475 T7351 onde posteriormente foram realizados ensaios de fadiga sob carga ou &#916K constantes, à temperatura ambiente de acordo com a Norma ASTM-E647 (1993). Para o ensaio sob carga constante foram obtidos os dados do estágio II e III da curva da/dN vs. &#916K. Para o ensaio de fadiga sob &#916K constante, quatro níveis de &#916K foram utilizados com taxas de crescimento de trinca variando entre 0,15 à 2,4 &#956m/ciclo. Adicionalmente foram realizados ensaios de tenacidade à fratura, KIC nas direções LT e TL conforme a Norma ASTM-E1820 (1999). A análise fratográfica por microscopia eletrônica de varredura foi conduzida no ensaio de fadiga a &#916K constante para determinar os espaçamentos inter-estrias. As taxas de propagação macroscópica e microscópica foram comparadas e boas correlações foram obtidas para um intervalo entre 0,1 a 1,0 &#956m/ciclo. Através da técnica proposta por Berkovitz (1995), o espectro de carregamento foi estimado através da técnica de parametrização do fator K e os resultados foram comparados ao espectro de carregamento real imposto pela máquina de ensaio. Utilizando o espaçamento inter-estrias local, SL, e para valores de &#916K menores que 23 MPam 1/2 (região de Paris), a estimativa de carregamento exibiu um erro menor que 15%. As vidas estimadas em propagação fornecidas pelas taxas microscópicas de propagação de trinca foram comparadas à vida real de propagação obtida a partir da taxa de propagação de trinca macroscópica e o erro absoluto entre ambos os valores foi menor que 15,7 %. Estes resultados sugerem que a vida em fadiga e o espectro de carga podem ser adequadamente estimados utilizando o espaçamento inter-estrias local, SL. / This work discusses the relationship between striation spacing, i.e. the microscopic crack propagation rate, SL (local) e SP (projected), as measured in post-mortem fractographic inspection of fatigue fractured surfaces, and the macroscopic crack propagation rate, da/dN, as monitored during fatigue crack growth tests. Compact tensile specimens C(T) were extracted in LT orientation from the core of a laminated plate of a SAE-AMS 7475-T7351 Al alloy and subsequently fatigue tested either at constant load or at constant &#916K, at room temperature, according to ASTM-E647. For constant amplitude loading fatigue tests, da/dN- &#916K data points were obtained for Regions II and III of crack growth curve. For constant &#916K fatigue tests, four &#916K levels were selected to give crack growth rates typically ranging from 0.15 to 2.4 &#956m/cycle. Additionally, KIC fracture toughness tests were performed in both LT and TL directions, according to ASTM E1820. SEM fractographic analysis was conducted on constant &#916K fatigue specimens, in order to determine striation spacing created during the fatigue test. Macro- and microscopic crack growth rates were compared and good correlation have been obtained for data within the range from 0,1 to 1,0 &#956m/ciclo. Using the technique proposed by Berkovitz, loading history was estimated by the K-factor parametrization and the results were compared to the true loading spectrum imposed by the testing machine. Using the local striation spacing SL and for &#916K values lower than 23 MPam 1/2 (Paris region), the estimated loading exhibits an error less than 15%. Propagation life estimated by local striation spacing (microscopic crack growth rate) was compared to the true propagation life obtained from macroscopic crack growth rate values and the absolute difference between them was less than 15,7%. These results suggest that both life and loading history can be adequately estimated using the local SL striation spacing values.

Este trabalho discutiu a relação entre o espaçamento inter-estrias , isto é, a taxa de propagação da trinca microscópica SL (local) e SP (projetada) e a taxa de propagação macroscópica , da/dN, obtido após o ensaio de propagação de trinca por fadiga. Corpos de prova compacto C(T) foram extraídos na orientação LT do centro de uma placa laminada de liga de alumínio SAE-AMS 7475 T7351 onde posteriormente foram realizados ensaios de fadiga sob carga ou &#916K constantes, à temperatura ambiente de acordo com a Norma ASTM-E647 (1993). Para o ensaio sob carga constante foram obtidos os dados do estágio II e III da curva da/dN vs. &#916K. Para o ensaio de fadiga sob &#916K constante, quatro níveis de &#916K foram utilizados com taxas de crescimento de trinca variando entre 0,15 à 2,4 &#956m/ciclo. Adicionalmente foram realizados ensaios de tenacidade à fratura, KIC nas direções LT e TL conforme a Norma ASTM-E1820 (1999). A análise fratográfica por microscopia eletrônica de varredura foi conduzida no ensaio de fadiga a &#916K constante para determinar os espaçamentos inter-estrias. As taxas de propagação macroscópica e microscópica foram comparadas e boas correlações foram obtidas para um intervalo entre 0,1 a 1,0 &#956m/ciclo. Através da técnica proposta por Berkovitz (1995), o espectro de carregamento foi estimado através da técnica de parametrização do fator K e os resultados foram comparados ao espectro de carregamento real imposto pela máquina de ensaio. Utilizando o espaçamento inter-estrias local, SL, e para valores de &#916K menores que 23 MPam 1/2 (região de Paris), a estimativa de carregamento exibiu um erro menor que 15%. As vidas estimadas em propagação fornecidas pelas taxas microscópicas de propagação de trinca foram comparadas à vida real de propagação obtida a partir da taxa de propagação de trinca macroscópica e o erro absoluto entre ambos os valores foi menor que 15,7 %. Estes resultados sugerem que a vida em fadiga e o espectro de carga podem ser adequadamente estimados utilizando o espaçamento inter-estrias local, SL. / This work discusses the relationship between striation spacing, i.e. the microscopic crack propagation rate, SL (local) e SP (projected), as measured in post-mortem fractographic inspection of fatigue fractured surfaces, and the macroscopic crack propagation rate, da/dN, as monitored during fatigue crack growth tests. Compact tensile specimens C(T) were extracted in LT orientation from the core of a laminated plate of a SAE-AMS 7475-T7351 Al alloy and subsequently fatigue tested either at constant load or at constant &#916K, at room temperature, according to ASTM-E647. For constant amplitude loading fatigue tests, da/dN- &#916K data points were obtained for Regions II and III of crack growth curve. For constant &#916K fatigue tests, four &#916K levels were selected to give crack growth rates typically ranging from 0.15 to 2.4 &#956m/cycle. Additionally, KIC fracture toughness tests were performed in both LT and TL directions, according to ASTM E1820. SEM fractographic analysis was conducted on constant &#916K fatigue specimens, in order to determine striation spacing created during the fatigue test. Macro- and microscopic crack growth rates were compared and good correlation have been obtained for data within the range from 0,1 to 1,0 &#956m/ciclo. Using the technique proposed by Berkovitz, loading history was estimated by the K-factor parametrization and the results were compared to the true loading spectrum imposed by the testing machine. Using the local striation spacing SL and for &#916K values lower than 23 MPam 1/2 (Paris region), the estimated loading exhibits an error less than 15%. Propagation life estimated by local striation spacing (microscopic crack growth rate) was compared to the true propagation life obtained from macroscopic crack growth rate values and the absolute difference between them was less than 15,7%. These results suggest that both life and loading history can be adequately estimated using the local SL striation spacing values.