JURČA Jan: The manufacturing of sheet metal part by deep draw technology. Thesis of Master´s Studies, the 5th Year of Study, the School-year 2008/2009, The Institute of Manufacturing Technology, Department of Machining, FSI VUT Brno.The thesis deals with the project of manufacturing the part of the car body – the fifth door by deep draw technology. The material is zinc-coated sheet metal HX220YD EN 10292. Mechanical properties and suitability of the material are evaluated by mechanical tests. The structure of the material is evaluated by metalography scratch pattern. The analysis of draw process and manufacturability of the part is made by calculations and AutoForm software. The production line, necessary machinery and construction solution of draw tool for the manufacturing the part are determined. Last section deals with economical evaluation of the production.

Ce travail de thèse a pour objet l’étude du comportement hydromécanique endommageable des géomateriaux non saturés. Plus précisément, cette recherche est appliquée à l’étude du comportement de galeries de stockage de déchets radioactifs en formation géologique profonde. Dans un premier temps, après avoir résumé les principaux traits du comportement hydromécanique des géomateriaux, en insistant sur l’effet de la succion et de l’endommagement mécanique, un nouveau modèle PPE-NS couplant les aspects hydromécaniques, de plasticité et d’endommagement isotrope est présenté. Etabli dans le cadre de la thermodynamique des milieux poreux, il est basé sur le concept de contrainte effective plastique et de la pression interstitielle équivalente. Supposant une distribution bimodale de tailles des pores pour les milieux poreux endommagés, l'effet d'endommagement sur le comportement hydraulique est modélisé au moyen des fonctions phénoménologiques. L’endommagement intervient donc aussi bien sur le comportement mécanique qu'hydraulique dans ce modèle. La prise en compte des contributions à l’énergie des interfaces venant à la fois de l'interaction mécanique entre les phases solide et fluide (via la pression équivalente) et du mécanisme physico-chimique de rétention d'eau (via la fonction de rétention d’eau) permet à ce modèle de décrire de façon pertinente le couplage bilatéral entre elles. Dans un deuxième temps, ce modèle rhéologique est appliqué au comportement de l’argillité du Callovo-Oxfordian, qui est potentiellement la roche hôte du stockage de déchets nucléaires en France, afin d’étudier les évolutions hydromécaniques d’une galerie type selon son cycle de vie simplifié. Tout d’abord, ce modèle est validé par des essais mécaniques et hydrauliques au laboratoire, en considérant des échantillons « homogènes ». Ensuite, l’approche analytique est utilisée pour constituer une solution exacte de référence de ce problème dans un cas limite d’une roche hôte poro-viscoplastique saturée. Cette solution permet de mieux comprendre l’effet du fluage sur le comportement de la galerie et aussi de tester la fiabilité d’autres solutions numériques complexes développées par la suite. Enfin, l’approche numérique des éléments finis est mise en œuvre afin d'implémenter le nouveau modèle PPE-NS dans un code de calcul initialement développé au LGCB (Laboratoire Génie Civil et Bâtiment). Sa validité est partiellement vérifiée en considérant le comportement « limite » en photoélasticité d'une galerie non revêtue ou des solutions quasi-analytiques ont été développées. Des études paramétriques dans le cas général d'un tunnel revêtu montrent la cohérence du modèle et mettent en lumière l’influence de la désaturation sur le comportement de la galerie. / This thesis aims to study the damageable hydromechanical behavior of unsaturated geomaterials. More precisely, the research is applied to study the behavior of underground galleries of radioactive waste disposals in deep geological formations. Firstly, after summarizing the main features of the hydro-mechanical behavior of geomaterials, emphasizing the effect of suction and damage, a new model PPE-N coupling hydromechanical interactions with plasticity and isotropic damage is presented. Established in the framework of thermodynamics of porous media, it is based on the concept of the so called plastic effective stress and equivalent pore pressure. Assuming a bimodal pore size distribution for cracked porous media and using the concept of bundle cylindrical capillaries, damage effects on hydraulic behaviour (water retention curve and hydraulic conductivity) is modelled using phenomenological functions. The accountance of the contributions to the interfacial energy from the mechanical internations between solid and fluid phases (via theequivalent pore pressure) as well as the physico-chemical mechanism of water retention (via the water retention function) enables this model to describe in apertinent manner bilateral couplings between them.Secondly, this constitutive model is applied to Callovo- Oxfordian argillite, which is the potential host rock for the French nuclear waste disposal, and then to study the evolution of the hydromechanical responses of an underground gallery according to its simplified life cycle. The model is first validated against a range of mechanical and hydraulic laboratory tests, considering "homogeneous" samples. The analytical approach is then used to provide an exact reference solution of this problem in the limiting case of a saturated poro-viscoplastic host rock. This solution allows to better understand the effect of creep on the behavior of the gallery and also to test the precision of other complex numerical solutions . Finally, the numerical approach using finite elemnts is used to implement the new model EPP-NS in a computer code originally developed in LGCB (Laboratoire Genie Civil et Batiment). Its validity is partly checked by examining the poroelastic behavior of an unlined tunnel where quasi-analytical solutions have been developed. Parametric studies in the generalcase of a lined tunnel demonstrate the consistency of the model and highlight the influence of desaturation on the behavior of the gallery.

Recently observed cumulation of unexpected collapses of slope-distant waste dumps in lignite mining areas of eastern germany re-initiated research of soil liquefaction. Especially it turned the question of internal initials that correspond to water rise. Parallel to laboritory tests and field experiments a micromechanical model should be developed, which can reproduce processes in the soil during saturation. In first approximation a partly saturated soil consists of two phases: the soil particles and the pore fluid. For micromechanical modeling a coupling of discontinuum particles) and continuum (fluid) is required. The soil particles can be simulated with the Discrete-Element-Method (DEM). For the pore fluid, which is assumed to be a mixture of liquid and gaseous fractions, Pore scale model with Finite Volumes (PFV) is used. At low water content liquid bridges (meniscii) arise between the particles that cause an apparent cohesion. The effect of the meniscii is considered by a correspondingly contact law in the DEM model. During the saturation of a soil both, cohesive effect and fluid bulk modulus, are reduced. In addition buoyancy acts on the particles during the process. The micromechanical modeling approach has the advantage, that just a few model parameters are needed. The numerical model shows pore fluid pressures during saturation process, that leads to a reduction of effective stress. It is investigated how much the reduction is regarding porosity, degree of saturation, stress conditions and grain shape. Furthermore the influence of model parameters as well as hydromechanics is investigated. The investigations are completed with another series of experiments under special conditions like integration of macropores, horizontal fixed model boundaries and abrupt saturation.:Einleitung Literaturauswertung Numerische Modellierung Modellstudien Ergebnisauswertung Zusammenfassung Extended summary

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[pt] Os problemas geotécnicos e geológicos envolvem a descrição do comportamento de materiais tais como solo e rocha e sua eventual interação com fluidos e estruturas. Em geral, a evolução desses problemas é caracterizada por grandes deformações e deslocamentos, descontinuidades, heterogeneidades e um comportamento constitutivo complexo. A abordagem deste tipo de problemas requer técnicas numéricas que levem em conta essas características, sem apresentar inconvenientes numéricos associados à distorção dos elementos como acontece no método dos elementos finitos (FEM). A presente tese desenvolve um algoritmo computacional baseado no método do ponto material (MPM) para aproximar a solução das equações governantes dos fenômenos mencionados. O algoritmo é baseado numa formulação dinâmica tridimensional do contínuo, considerando grandes deformações. Os amortecimentos de Rayleigh o local não viscoso são incorporados para modelar problemas dinâmicos e quase-estáticos. A geração dinâmica das poro-pressões é formulada assumindo o meio poroso saturado e um ponto material para discretizar a mistura. Diversas técnicas de suavização das pressões são avaliadas em problemas de impacto sobre meios saturados. Diferentes modelos constitutivos são implementados para modelar tanto a formação da superfície de ruptura e o processo de escoamento da massa de solo durante as instabilidades, quanto a gênese, evolução e quantificação de zona de falhas nos processos geológicos. Para a abordagem da discretização de problemas de escala geológica de grande número de partículas usando o MPM, uma metodologia é proposta e verificada com a discretização do deslizamento do Daguangbao, na China. Visando à diminuição do tempo computacional, o algoritmo é implementado segundo o paradigma de programação paralela. / [en] Geotechnical and geological problems involve the description of the behavior of materials such as soil and rock, and their eventual interaction with fluids and structures. In general, the evolution of these problems is characterized by large deformations and displacements, discontinuities, heterogeneities and complex constitutive behavior. Addressing these problems requires numerical techniques that take these characteristics into account, without numerical drawbacks associated with element distortion as occurs in the finite element method (FEM). In this thesis is developed a computational algorithm based on the material point method (MPM) to approximate the solution of the governing equations to the mentioned phenomena. The algorithm is based on a three-dimensional dynamic formulation of the continuum considering large deformations. Rayleigh damping and non-viscous local damping are incorporated to model dynamic and quasi-static problems. The dynamic generation of pore pressures is formulated assuming the saturated porous medium and a single material point to discretize the mixture. Different techniques are evaluated to mitigate spurious pressure in impact problems on saturated media. Different constitutive models are implemented to model the failure surface and the soil mass flow process during slope instabilities, as well as the genesis, evolution and failure zone quantification in geological processes. To address the discretization of large-scale geological problems using MPM, a methodology is proposed and validated with the discretization of the Daguangbao landslide, in China. In order to decrease the computational time, the algorithm is implemented according to the parallel programming paradigm.

Sedimentary rocks are characterized with very low permeability (in the order of 10-22 m2), low diffusivity, a possible self-healing of fractures, and a good capacity to retard radionuclide transport. In recent years, sedimentary rocks are investigated by many research groups for their suitability for the disposal of radioactive waste. Development of deep geologic repositories (DGRs) for the storage of radioactive waste within these formations causes progressive modification to the state of stress, to the groundwater regime, and to the chemistry of the rock mass. Thermal effects due to the ongoing nuclear activity can cause additional disturbances to the system. All these changes in the system are coupled and time-dependent processes. These coupled processes can result in the development of an excavation damaged zone (EDZ) around excavations. More permeable than the undisturbed rock, the EDZ is likely to be a preferential pathway for water and gas flow. Consequently, the EDZ could be a potential exit pathway for the radioactive waste to biosphere. An investigation of the Hydraulic-Mechanical (HM) and Thermal-Hydraulic-Mechanical-Chemical (THMC) behaviour of sedimentary rock formations is essential for the development of DGRs within such formations. This research work consists of (1) an experimental investigation of the mechanical behaviour of the anisotropic Tournemire argillite, (2) modeling of the mechanical behaviour of the Tournemire argillite, and (3) numerical simulations of the mechanical and hydromechanical behavior of two host sedimentary rocks, the Tournemire argillite and Cobourg limestone, for deep geological repository for nuclear wastes. The experimental program includes the measurements of the physical properties of the Tournemire argillite and its mechanical response to loading during uniaxial compression tests, triaxial compression tests with different confining pressures, unconfined and confined cyclic compression tests, Brazilian tests, and creep tests. Also, acoustic emission events are recorded to detect the initiation and propagation of microcracks within the rock during the uniaxial testing. The approach for modeling the mechanical behaviour of the Tournemire argillite consists of four components: elastic properties of the argillite, a damage model, the proposed concept of mobilized strength parameters, and the classical theory of elastoplasticity. The combination of the four components results in an elastoplastic-damage model for describing the mechanical behaviour of the Tournemire argillite. The capabilities of the model are evaluated by simulating laboratory experiments. Numerical simulations consist of: (1) a numerical simulation of a mine-by-test experiment at the Tournemire site (France), and (2) numerical simulations of the mechanical and hydromechanical behaviour of the Cobourg limestone within the EDZ (Canada). The parameters influencing the initiation and evolution of EDZ over time in sedimentary rocks are discussed.

Sedimentary rocks are characterized with very low permeability (in the order of 10-22 m2), low diffusivity, a possible self-healing of fractures, and a good capacity to retard radionuclide transport. In recent years, sedimentary rocks are investigated by many research groups for their suitability for the disposal of radioactive waste. Development of deep geologic repositories (DGRs) for the storage of radioactive waste within these formations causes progressive modification to the state of stress, to the groundwater regime, and to the chemistry of the rock mass. Thermal effects due to the ongoing nuclear activity can cause additional disturbances to the system. All these changes in the system are coupled and time-dependent processes. These coupled processes can result in the development of an excavation damaged zone (EDZ) around excavations. More permeable than the undisturbed rock, the EDZ is likely to be a preferential pathway for water and gas flow. Consequently, the EDZ could be a potential exit pathway for the radioactive waste to biosphere. An investigation of the Hydraulic-Mechanical (HM) and Thermal-Hydraulic-Mechanical-Chemical (THMC) behaviour of sedimentary rock formations is essential for the development of DGRs within such formations. This research work consists of (1) an experimental investigation of the mechanical behaviour of the anisotropic Tournemire argillite, (2) modeling of the mechanical behaviour of the Tournemire argillite, and (3) numerical simulations of the mechanical and hydromechanical behavior of two host sedimentary rocks, the Tournemire argillite and Cobourg limestone, for deep geological repository for nuclear wastes. The experimental program includes the measurements of the physical properties of the Tournemire argillite and its mechanical response to loading during uniaxial compression tests, triaxial compression tests with different confining pressures, unconfined and confined cyclic compression tests, Brazilian tests, and creep tests. Also, acoustic emission events are recorded to detect the initiation and propagation of microcracks within the rock during the uniaxial testing. The approach for modeling the mechanical behaviour of the Tournemire argillite consists of four components: elastic properties of the argillite, a damage model, the proposed concept of mobilized strength parameters, and the classical theory of elastoplasticity. The combination of the four components results in an elastoplastic-damage model for describing the mechanical behaviour of the Tournemire argillite. The capabilities of the model are evaluated by simulating laboratory experiments. Numerical simulations consist of: (1) a numerical simulation of a mine-by-test experiment at the Tournemire site (France), and (2) numerical simulations of the mechanical and hydromechanical behaviour of the Cobourg limestone within the EDZ (Canada). The parameters influencing the initiation and evolution of EDZ over time in sedimentary rocks are discussed.

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