O presente trabalho analisa o impacto do exercício da repressão penal sobre os usuários de crack na busca pelo tratamento, avaliando a coerência entre os fins declarados pela atual política de drogas e os meios previstos em lei para sua consecução. O estudo se desenvolveu por meio de pesquisa qualitativa com seres humanos operada através de entrevistas com usuários e ex-usuários de crack em tratamento, bem como com os profissionais da equipe multidisciplinar do local de tratamento. / This paper analyzes the impact of criminal repression on crack users seeking treatment, evaluating the coherence between the purposes declared by the current drug policy and the means provided by law for its achievement. This paper was conducted by means of a qualitative research with humans beings, operated through interviews with crack users and former users in treatment, as well as with professionals in the multidisciplinary team from the treatment site.

Abstract: The process of inspecting welds done in production at Volvo Aero in Trollhättan is timeconsuming and a lot of this time goes into examining faulty objects. The aim of this thesis is to startdevelopment of a system that analyses acoustic emission from cooling welds to determine the qualityof the weld. Our aim is to be able to detect cracks in the material and to give information on thecracks using the data gathered by our sensors. To do this we will use methods to locate sound sourcesand then rate our findings and do some simplifications on the result of our calculations. We willanalyze our calculated data to find crack signatures and classify our findings and give alarms if wefind cracks that are considered too big for comfort. We will also give insight in to future aspects of ourwork and look at ways to improve on our proposed methods. We will discuss our systems pros, consand what things have been taken into consideration during design, and what strategies we proposeto handle the results from the system.

A problem has been observed by many researchers regarding the cracks caused mainly by moisture variation in timber structures. However, this effect has been neglected over the past decades. In addition, many design codes do not have a room for a realistic formulation of the moisture diffusion and its effect in causing internal stress, deformation, and cracks. Moreover, if this effect occurs in connection areas, usually the weakest structural section, it has and also had shown a devastating effect on the service life of many wooden structures. In the current work, a Fickian moisture diffusion model is implemented by use of finite element simulation with the help of the commercial software ABAQUS for a dowelled beam column connection. The results of such moisture diffusion were used to analyse the stress situation inside the timber section. Moreover, an extended finite element method was applied in ABAQUS to investigate how moisture induced crack develops into the timber section. Furthermore, a parametric study was performed by using Python scripting to investigate the effect of dowel spacing (horizontal and vertical) and critical energy release rate on the development of the moisture-induced crack. The results obtained revealed that for the same material property when the dowel spacing increases (either horizontal or vertical) the crack length increases significantly. Likewise, the crack length increases when the critical energy release rate requirement of the timber is decreasing.

Corrosion and fatigue have been dominant degradation mechanisms in offshore structures, with the combination of the two, known as corrosion fatigue, having amplified effects in structures in the harsh marine environments. Newer types of structure are now being developed for use in highly dynamic, harsh marine environments, particularly for renewable energy applications. However, they have significantly different structural details and design requirements compared to oil and gas structures, due to the magnitude and frequency of operational and environmental loadings acting on the support structures. Therefore, the extent of corrosion assisted fatigue crack growth in these structures needs to be better understood. In this research, fatigue crack growth in S355J2+N steel used for offshore wind monopile fabrications was investigated in air and free corrosion conditions. Tests were conducted on parent, HAZ and weld materials at cyclic load frequencies similar to what is experienced by offshore wind monopile support structures. The seawater used for testing was prepared according to ASTM D1141 specifications and was circulated past the specimens through a purpose designed and built corrosion rig at a rate of 3 l/min, at a temperature of 8-100C and at a pH of 7.78-8.1. A new crack propagation method accompanied by constant amplitude loading was used. Crack growth rates in parent, HAZ and weld materials were significantly accelerated under free corrosion conditions, at all the stress ratios used compared to in air environment. However, in free corrosion conditions, crack growth rates in the parent, HAZ and weld materials were similar, particularly at a lower stress ratio. The results are explained with respect to the interaction of the loading condition, environment and the rate of material removal by corrosion in the weldments. A new model was developed to account for mean stress effects on crack growth rates in air and in seawater, and was found to correlate well with experimental data as well as with the other mean stress models tested.

Orientador: Valdir Alves Guimarães / Banca: Aelcio Zangrandi / Banca: Marcos Venicius Soares Pereira / Resumo: Atualmente a crescente necessidade de aumento da carga por eixo e do número de passageiros transportados pelos trens, fez com que as ferrovias em todo o mundo iniciassem pesquisas voltadas para o desenvolvimento de novos materiais e processamentos térmicos. O aumento da confiabilidade dos sistemas ferroviários é uma exigência do mercado, o que é definido como sendo a garantia de que não ocorra falhas nos componentes no período entre as inspeções de rotina, ou seja, que um defeito possa ser detectado e reparado antes que atinja um tamanho crítico que leve a ruptura do componente. Por se tratar de um equipamento fundamental nos trens, os eixos ferroviários são alvos de grande parte das recentes pesquisas na área de fadiga, desenvolvimento de novos materiais e segurança dos intervalos de inspeção, uma vez que sua falha, certamente ocasionará um descarrilamento do vagão ou locomotiva. O comportamento em fadiga dos materiais empregados na fabricação de eixos ferroviários vem sendo estudado através de ensaios de propagação de trinca por fadiga, a fim de se obter dados experimentais para definição de intervalos de inspeção. Neste trabalho, foram estudados os aços SAE-1050, comumente utilizado na fabricação de eixos ferroviários, e o SAE- 4130, que recentemente vem sendo empregado para este fim. Estes materiais foram processados por dois diferentes tipos de tratamentos térmicos, sendo um composto por normalização e alívio de tensões, e o outro por normalização, têmpera e revenimento. O comportamento mecânico dos aços foi avaliado através de ensaios de tração, charpy em diversas temperaturas e tenacidade à fratura ( IC K ). O comportamento em fadiga, por sua vez, foi avaliado através de ensaios de propagação de trinca por fadiga, realizados em corpos de prova tração compacto (CT). Para a determinação da influência da razão... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Currently the growing need of increase in axle load and numbers of passengers transported by the trains, prompted the railroads all over the world began researches about the development of new materials and heat treatments. The increase of the reliability for railway systems is a requirement of the market, and can be defined as the warranty that doesn't occur failures in the components between the inspection intervals, in other words, that a defect can be detected and repaired before it reaches a critical size to take the rupture of the component. Axles are one of the most important components in railway vehicle, thus are present in the great part of the recent researches into fatigue, new materials and safe inspection intervals, since its flaw, certainly will cause a derailment of the wagon or locomotive. The fatigue behavior of the employed materials in the production of railway axles has been studied with aid of fatigue crack growth tests, in order to obtain experimental data for definition of inspection intervals. The present work, studied the steels SAE-1050, commonly used in the production of railway axles, and SAE-4130, that recently has been used for this application. These materials were submitted to different heat treatments: normalizing and stress relief, and normalizing, quenching and tempering. The mechanical properties of the steels were evaluated through tensile test, impact test in different temperatures and fracture toughness test. The fatigue behavior was evaluated through of fatigue crack growth tests in compact tension specimens (CT). The influence of the load ratio " R ", on fatigue crack growth was evaluated using the ratio of 0,1 and 0,3. The results showed that the steel SAE-4130, normalized, quenched and tempered, achieved the best mechanical properties and the smallest fatigue crack growth rate, being therefore, the best option as... (Complete abstract click electronic acccess below) / Mestre

This master thesis deals with optimalization of stiffened integral wing panel of L-610 aircraft to its fatique life. Analysis has been made using FEM, AFGROW software and PYTHON language.

Ce travail a pour objectif d’étudier la fissuration des sols due au séchage par des approches numérique et analytique. L’initiation et la propagation des fissures sont investiguées en utilisant un code de calcul aux éléments finis avec la présence des joints cohésifs. Les couplages entre le problème hydraulique et le comportement mécanique en présence des discontinuités sont considérés. La loi de la fissure cohésive est appliquée pour modéliser l’initiation et la propagation des fissures.Tout d’abord, les résultats d’un essai de séchage au laboratoire réalisé sur un sol argileux à l’état liquide sont utilisés afin d’évaluer la méthode numérique proposée. Les résultats numériques montrent que le modèle est capable de reproduire les tendances principales du processus de séchage. Elle souligne aussi l’importance des conditions aux limites dans l’initiation des fissures. Ensuite, une approche énergétique est proposée pour étudier l’initiation d’une fissure. Les énergies élastiques avant et après l’initiation de la fissure sont estimées par les deux approches analytique et numérique. L’énergie dissipée lors de l’initiation de la fissure est comparée avec le taux d’énergie pour créer une fissure. Les analyses montrent que le critère d’énergie peut est atteint avant le critère de contrainte. La dissipation de l’énergie cumulée correspond à la propagation instable lors de l’initiation de la fissure. De plus, le développement et la géométrie des fissures sont étudiés essentiellement par les simulations numériques avec plusieurs joints cohésifs. Les résultats numériques montrent que la fissuration se produit souvent progressivement pour former différentes familles de fissures par un processus dichotomique (une fissure apparait au milieu de deux fissures existantes). La propagation d’une fissure est brutale dans la phase d’initiation pour atteindre une profondeur appelée ‘ultime’. Les fissures dans chaque famille peuvent apparaitre simultanément à un même niveau de succion et présentent une même profondeur ultime. En se basant sur les résultats numériques et quelques analyses analytiques supplémentaires, des relations empiriques sont proposées afin de prédire l’espacement et la profondeur ultime des fissures. Finalement, quelques calculs préliminaires sont réalisés afin d’évaluer le potentiel de la méthode numérique proposée pour prédire la fissuration liée au séchage des ouvrages en terre / This work focuses on the analysis of desiccation cracking by numerical and analytical approaches. The initiation and the propagation of cracks are investigated by using a finite element code including cohesive joints elements. Coupling between the hydraulic and the mechanical processes in the presence of discontinuities is considered. The cohesive crack’s law is applied to simulate the initiation and the propagation of cracks.Results of a laboratory experiments performed on slurry clay soil are first used to evaluate the proposed numerical modelling method. The results show that the method is able to reproduce the main trends of desiccation process. The importance of boundary conditions are also discussed. Second, an energy approach is proposed to study the initiation of cracks. The energies before and after crack initiation are estimated by both numerical and analytical solutions. The energy released by cracking is then compared to the crack energy to discuss crack initiation conditions. The analysis shows that the energy criterion is reached before the stress criterion, and this can explain unstable crack propagation at the beginning. Third, the development and the geometry of desiccation cracks are studied by numerical simulation with several cohesive joints. The numerical results show that cracking occurs sequentially to form different cracks families with a dichotomy process (the subsequent cracks appear at the middle of two existing neighboring ones). The cracks in each family appear simultaneously and reach an identical ultimate depth. From the numerical results and additional analytical analysis, empirical correlations are proposed to predict the spacing and crack depth. Finally, some preliminary studies are performed showing that the proposed numerical method can be used to predict the desiccation crack phenomena observed on geotechnical earth structures

Rock slope failures leading to rock falls and rock slides are caused by a multitude of factors, including seismic activity, weathering, frost wedging, groundwater and thermal stressing. Although these causes are generally attributed as separate causes, some of them will often act together to cause rock slope failures. In this work, two of the above factors, seepage of water through cracks and crack propagation due to the after effects of blasting are considered. Their combined impact on the development of rock falls and rock slides is modeled on ANSYS workbench using the Bingham Canyon mine slope failure of 2013 as a case study. Crack path modeling and slope stability analysis are used to show how a combination of crack propagation and seepage of water can lead to weakening of rock slopes and ultimate failure. Based on the work presented here, a simple approach for modeling the development of rock falls and rock slides due to crack propagation and seepage forces is proposed. It is shown how the information from remote sensing images can be used to develop crack propagation paths. The complete scope of this method involves demonstrating the combination of basic remote sensing techniques combined with numerical modeling on ANSYS workbench.

Epoxy-coated rebar (ECR) has been used in approximately 300 Florida bridges, in an attempt to control corrosion of the substructure in the splash-evaporation zone. Early severe ECR corrosion was observed in the substructure of several Florida ECR bridges (Group 1) where the substructure was built with permeable concrete of high apparent chloride diffusivity DApp. Other ECR bridges built during the same period and having similar DApp were projected to show corrosion damage starting on the following decade. Examination of several of those bridges (Group 2) confirmed that projection. Other recently examined Florida ECR bridges (Groups 3 and 4) were built with very low to moderate permeability concrete having correspondingly low to moderate DApp values at normally sound concrete locations. Those bridges were projected not to show early corrosion at normal locations and that projection has also been confirmed. However, some incidence of thin structural cracks exists affecting a small fraction of the substructure. Chloride transport there is much faster than through the matrix in otherwise low permeability concrete and work has confirmed that early corrosion can develop there. A predictive ECR corrosion model was applied that replicated most of the damage function features observed in the field. The model divides the substructure in separate elements with individual chloride exposure, concrete permeability, concrete rebar cover, and extent of ECR coating imperfections. Additionally, a model for projecting impact of preexisting cracking on corrosion damage was developed. The projections indicate that relatively isolated cracking should only create topical concrete damage with reduced maintenance requirements. However, model projections indicated that even though assuming that the incidence of damage is limited to a small region around the crack, if the crack orientation with respect to the rebar were adverse and chloride transport were greatly enhanced (as it could be expected in relatively wide cracks), corrosion damage from localized concrete deficiencies could significantly increase maintenance costs. Electrochemical Impedance Spectroscopy (EIS) measurements of ECR in extracted cores showed good potential for non destructive characterization of the extent of coating damage. A possible method accounting for frequency dispersion effects in the high frequency response (of importance to assess extent of defects) was introduced.

This thesis work is a continuation of a project aimed at the consolidation of insulation material (IM) to produce porous ceramics with sufficient porosity and compression strength for post-insulation of buildings. The porous structure and contact points are tailored to produce IM with ultra-low thermal conductivity.  One of the main goals is to introduce expandable microspheres, that are perfect lightweight fillers and blowing agents into production. They are relatively new materials in the market which are used to manufacture products with low weight and controlled foam structure. Therefore, it is of interest to be integrated into the construction field as a component for insulating materials.  The project is built on the advanced structuring of porous materials with tailored porosity to offer 5-10 times lower thermal conductivity value providing adequate insulation with an insulation cover of 2-10 mm in thickness. Enhancing the insulating capacity allows to limit the use of energy to improve energy efficiency. Thus, less energy is required to heat or cool the indoor climate. The success in achieving such thin effective IM will eliminate the need for any modification of existing window frames, electrical and heating installations. In the first stage, it is necessary to confirm the entire concept of creating a thermal IM with a controlled porous structure using various compositions of materials and an assessment of the structure, porosity, and functional properties. This project focuses on developing a composition of ceramic panels. The various components of the ceramic panels including the type of ceramic are adjusted and their effects on the composition are described. Pure alumina, activated alumina and silica have been investigated to find the optimized quality and price. In addition, various methods and conditions have been implemented for panel fabrication.  Prototypes of ceramic panels are prepared for demonstration, followed by upscaling at the facilities of industrial partners. The project has been performed in collaboration with companies i.e., Nouryon, HIPOR Materials AB, and LindePac AB as the industrial partner.