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.

Für die Weich- und Mittelhartzerkleinerung von Primär- und Sekundärrohstoffen werden zunehmend Profilwalzenbrecher eingesetzt. Trotz relativ geringer Zerkleinerungsgrade zeichnen sie sich durch einen geringen spezifischen Leistungsbedarf, hohe Durchsätze, eine einfache Konstruktion und Instandhaltung sowie eine störungsfreie Betriebsweise aus und sind auch bei adhäsivem Aufgabematerial anwendbar. Trotz der Bedeutung dieser Maschinen gibt es bisher nur unzureichende Auslegungsmethoden. Die theoretisch begründete Modellierung der Zerkleinerung in markant profilierten Walzenbrechern ist deshalb Gegenstand dieser Arbeit, um dadurch die Dimensionierungsgrundlagen zu verbessern und Einsatzmöglichkeiten in der Hartzerkleinerung abzuschätzen. Dazu werden im Rahmen einer Systembetrachtung zunächst die wesentlichen Prozessparameter der Zerkleinerung ermittelt und die Bauarten von Profilwalzenbrechern klassifiziert (Kapitel 2). Die Darstellung der bekannten Berechnungsmodelle für die Hauptzielgrößen „Grenzdurchsatz“, „Produktgranulometrie“ und „Leistungsbedarf“ ist Gegenstand von Kapitel 3. Darauf aufbauend wird in Kapitel 4 ein neues, physikalisch begründetes Auslegungsmodell vorgestellt und das Untersuchungsfeld hinsichtlich der zu analysierenden Aufgabestoffart und Maschinengeometrie eingegrenzt. Die für dieses Modell erforderlichen Zerkleinerungstest- und Simulationsergebnisse werden in Kapitel 5 und 6 dargestellt, bevor die Arbeit in Kapitel 7 mit einer Zusammenfassung und einem Ausblick abschließt.:Symbolverzeichnis III Tabellenverzeichnis XX Abbildungsverzeichnis XXI 1 Einleitung und Problemstellung 1 2 Systemanalyse von Profilwalzenbrechern 3 2.1 Einfluss- und Zielgrößen von Profilwalzenbrechern 3 2.2 Systematisierung und Einordnung von Profilwalzenbrechern 7 2.2.1 Klassifizierung von Profilwalzenbrechern 8 2.2.1.1 Klassifizierung nach konstruktiven Maschinenparametern 9 2.2.1.2 Klassifizierung nach der Belastungsart 18 2.2.2 Abgrenzung von Profilwalzenbrechern 25 3 Erkenntnisstand zur Zerkleinerung in Profilwalzenbrechern 29 3.1 Wertebereiche der Einfluss- und Zielgrößen von Profilwalzenbrechern 29 3.2 Auslegungsmodelle von Profilwalzenbrechern 32 3.2.1 Ermittlung des Grenzdurchsatzes 32 3.2.1.1 Einzugsbedingung für das Einzelkorn 32 3.2.1.2 Theoretisch begründete Ansätze für den Grenzdurchsatz 38 3.2.1.3 Empirische Ansätze für den Grenzdurchsatz 47 3.2.2 Ermittlung der Produktkorngrößenverteilung 49 3.2.3 Ermittlung des Leistungsbedarfs 54 3.2.3.1 Theoretisch begründete Ansätze für den Leistungsbedarf 57 3.2.3.2 Empirische Ansätze für den Leistungsbedarf 68 3.3 Wertung des Erkenntnisstandes und Präzisierung der Aufgabenstellung 75 4 Neues Auslegungsmodell für Profilwalzenbrecher 77 4.1 Aufbau des Modells 77 4.2 Voruntersuchungen zu den Einflussgrößen des Modells 78 4.2.1 Analyse maschinenbezogener Parameter 78 4.2.1.1 Primäroptimierung der Profilwalzengeometrie 79 4.2.1.2 Sekundäroptimierung der Profilwalzengeometrie 86 4.2.2 Analyse aufgabestoffbezogener Parameter 95 4.2.3 Analyse systembezogener Parameter 99 4.3 Bestimmung der Zielgrößen des Modells 101 4.3.1 Simulation der Einzelkornzerkleinerung in einem Modellwalzenbrecher 101 4.3.2 Aggregation der Simulationsergebnisse auf die Massestromzerkleinerung 102 4.3.3 Skalierung der Simulationsergebnisse auf den Originalwalzenbrecher 110 5 Zerkleinerungsversuche für das neue Auslegungsmodell 115 5.1 Grundlagen zur Einzelkorndruckzerkleinerung 115 5.1.1 Physikalische Beschreibung von Deformations- und Bruchprozessen 115 5.1.2 Empirische Analyse von Deformations- und Bruchprozessen 121 5.1.2.1 Einfluss- und Zielgrößen der Einzelkorndruckzerkleinerung 121 5.1.2.2 Korngrößeneffekt der Einzelkorndruckzerkleinerung 124 5.1.2.2.1 Versuchsergebnisse zum Korngrößeneffekt 124 5.1.2.2.2 Mathematisch-statistische Ansätze zum Korngrößeneffekt 128 5.2 Experimentelle Untersuchungen zur Einzelkorndruckzerkleinerung 132 5.2.1 Aufbau der Versuchsapparaturen 132 5.2.2 Durchführung der Versuche 134 5.2.3 Auswertung der Versuche 136 6 DEM-Simulationen für das neue Auslegungsmodell 141 6.1 Grundlagen zur DEM-Simulation 141 6.1.1 Beschreibung der DEM 141 6.1.2 Bisherige DEM-Simulationen von Zerkleinerungsprozessen 151 6.2 Kalibrierung des DEM-Gesteinsmodells 154 6.2.1 Statistische Simulationsplanung 156 6.2.2 Simulationsdurchführung 159 6.2.3 Voroptimierung 161 6.2.4 Nachoptimierung 164 6.3 Walzenbrechersimulationen mit dem kalibrierten DEM-Gesteinsmodell 166 6.3.1 Aufbau des Walzenbrechersimulationsprogramms 166 6.3.2 Ergebnisse der Walzenbrechersimulationen 169 6.3.2.1 Simulationsergebnisse zum Massedurchsatz des Walzenbrechers 169 6.3.2.2 Simulationsergebnisse zur Produktkorngrößenverteilung des Walzenbrechers 171 6.3.2.3 Simulationsergebnisse zum Leistungsbedarf des Walzenbrechers 174 7 Zusammenfassung und Ausblick 178 Literaturverzeichnis XXIV Anlagenverzeichnis XXXV

Die am häufigsten für die Zerkleinerung des Zementklinkers eingesetzte Kugelmühle stellt eine relativ einfache Maschine dar, in der sehr komplizierte dynamische Wechselwirkungen herrschen. Die direkte Messung der Beanspruchungsintensitäten ist heutzutage immer noch eine schwierige Aufgabe. In der vorliegenden Arbeit sind die Spektren der Beanspruchungsgrößen sowie einige spezifische integrale Größen mit der Methode der diskreten Elemente (DEM) untersucht worden. Eine besondere Aufgabe bestand in der Ermittlung der Parameter des viskoelastischen Kontaktmodells und der den Zementklinker charakterisierenden mechanischen Größen. Die reale Abbildung der Stoßvorgänge wurde anhand vereinfachter Modelle der Messprüfstände validiert. Mit den ermittelten Parametern sind numerische Untersuchungen durchgeführt worden, mit denen ihre Auswirkung auf die Zielgrößen bestimmt wurde. In Hinsicht auf eine mögliche konstruktive Weiterentwicklung sind Simulationen mit festgelegten betrieblichen und zu variierenden konstruktiven Parametern durchgeführt worden.

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

High-level radioactive waste (HLW) poses threat to the biosphere. Geological disposal is accepted as a safe way for HLW disposal. Waste canisters made of Sintered Silicon Carbide (SSiC) are proposed and geomechanical safety aspects relating to such SSiC canisters are investigated. First part of the thesis reviews the state-of-the-art and demands for HLW disposal. The reason for considering Silicon Carbide (SiC) as canister material is explained. Especially in terms of corrosion and lifetime, ceramics and especially SiC is superior to metals or concrete. The only concern is its brittle behavior. The second part of the thesis presents results on static and dynamic mechanical properties of SiC in general and in particular for SSiC based on literature review and own lab tests. Although strength values for SiC and especially SSiC are very high, the extreme brittle behavior has to be considered in case of impact or point-like loading. The third and most extensive part of the thesis part contains numerical simulations, which consider most critical potential loading situations during transport and installation of the canisters underground. Both, pure elastic continuum and DEM based models are used considering the following loading situations (critical scenarios): Freefall of canister during transport or installation (FF), Impact by falling rock block at disposal site (RF), Point loading due to accidental insertion of small stone below the canister (PL), Anisotropic earth pressure loading after disposal (EP). Coating to protect the canisters against damage is investigated and preliminary parameters in terms of stiffness and thickness are recommended.

No description available.

<p>A procedure for calibrating a discrete element (DE) computational soil model for various moisture contents using a conventional Asperity-Spring friction modeling technique is presented in this thesis. The procedure is based on the outcomes of two physical soil experiments:</p> <p>(1) Compression and (2) unconfined shear strength at various levels of normal stress and normal pre-stress. The Compression test is used to calibrate the DE soil plastic strain and elastic strain as a function of Compressive stress. To calibrate the DE inter-particle friction coefficient and adhesion stress as a function of soil plastic strain, the unconfined shear test is used. This thesis describes the experimental test devices and test procedures used to perform the physical terramechanical experiments. The calibration procedure for the DE soil model is demonstrated in this thesis using two types of soil: sand-silt (2NS Sand) and silt-clay(Fine Grain Soil) over 5 different moisture contents: 0%, 4%, 8%, 12%, and 16%. The DE based models response are then validated by comparing them to experimental pressure-sinkage results for circular disks and cones for those two types of soil over 5 different moisture contents. The Mean Absolute  Percentage Error (MAPE) during the compression calibration was 26.9% whereas during the unconfined shear calibration, the MAPE was calculated to be 11.38%. Hence, the overall MAPE was calculated to be 19.34% for the entire calibration phase.</p>

Soil erosion by water is a main form of land degradation worldwide. The problem has been addressed, among others, in the United Nations Sustainability Goals. However, for mitigation of erosion consequences and adequate management of affected areas, reliable information on the magnitude and spatial patterns of erosion is needed. Although such need is often addressed by erosion modelling, precise erosion monitoring is necessary for the calibration and validation of erosion models and to study erosion patterns in landscapes. Conventional methods for quantification of rill erosion are based on labour-intensive field measurements. In contrast, remote sensing techniques promise fast, non-invasive, systematic and larger-scale surveying. Thus, the main objective of this study was to develop and evaluate automated and transferable methodologies for mapping the spatial extent of erosion rills from a single acquisition of remote sensing data. Data collected by an uncrewed aerial vehicle was used to deliver a highly detailed digital elevation model (DEM) of the analysed area. Rills were classified by two methods with different settings. One approach was based on a series of decision rules applied on DEM-derived geomorphological terrain attributes. The second approach utilized the random forest machine learning algorithm. The methods were tested on three agricultural fields representing different erosion patterns and vegetation covers. Our study showed that the proposed methods can ensure recognition of rills with accuracies between 80 and 90% depending on rill characteristics. In some cases, however, the methods were sensitive to very small rill incisions and to similar geometry of rills to other features. Additionally, their performance was influenced by the vegetation structure and cover. Besides these challenges, the introduced approach was capable of mapping rills fully automatically at the field scale and can, therefore, support a fast and flexible assessment of erosion magnitudes.

Syftet med fallstudien var att undersöka möjligheterna och nyttan med att implementera en höjdmodell med högre upplösning i SMHI:s översvämningsmodellering som tillämpar den hydrauliska modellen LISFLOOD-FP. SMHI utfärdar översvämningsvarningar och det är därför av vikt att översvämningsmodelleringen håller hög kvalitet. Samtidigt kräver modelleringen tid och resurser från Nationellt Superdatorcentrum i Linköping, NSC. Därför vägdes de potentiella fördelarna med högre upplösning mot förlängd körtid. Fallstudien bestod av två delar där en höjdmodell på två meters upplösning i xy-planet implementerades och jämfördes med den i dagsläget uppställda modellen på fem meters upplösning. Detta gjordes genom att återskapa översvämningstillfällen med dess flöden från S-HYPE och mätningar. I studiens första del hämtades satellitdata från Copernicus från två tidigare översvämningstillfällen för validering av över-svämningsmodelleringen. De tidigare översvämningstillfällena var dels i Emån i Småland år 2012 och dels i Västerdalälven i Dalarna år 2018. Ett index för passning beräknades mellan översvämningskartorna producerade med två respektive fem meters upplösning gentemot satellitbilderna för att kvantifiera överlappande ytor. Därtill beräknades vattendragens lutning för att undersöka om det fanns indikationer på något samband med förändring i index med ökad upplösning på höjdmodellen. Studiens andra del bestod i att undersöka hur höjdmodellens upplösning påverkar vattnets spridning kring översvämningsvallar i modellen. I undersökningen återskapades ett översvämningstillfälle från 2020 i Helige å i Småland. Ett antal delavrinningsområden visade sig instabila för den högre upplösta höjdmodellen och kunde därför endast simuleras med lägre flöden. Erhållna resultat visade dock på att översvämningskarteringen förbättrades med upplösningen två meter vid jämförelse med data från Copernicus. Körtiden ökade dock med över 12 gånger vid simulering av högre upplösning. Vidare visades tröskeleffekter i studiens resultat, då översvämnings-vallen stoppade vattnet i den högre upplösta höjdmodellen men inte i den med lägre upplösning. På grund av stabilitetsproblemet och studiens begränsade omfattning, kunde slutsats inte dras om huruvida SMHI bör implementera en höjdmodell med två meters upplösning i systemet för översvämningsvarningar. Däremot kunde konstateras att stabiliteten i modellen måste öka för att det ska vara möjligt. Slutligen drogs slutsatsen att det förekommer tröskeleffekter mellan de två höjdmodellerna och att prestandan ökar generellt för den högre upplösningen när det kommer till precisionen i översvämningsmodelleringen. / The purpose of this case study was to examine the possibilities and advantages of implementing a DEM with higher resolution in inundation modelling at SMHI, the Swedish Meteorological and Hydrological Institute, which uses the hydraulic model LISFLOOD-FP. The institute issues flood warnings and therefore it is of high importance that the innundation modelling gives adequate results. On the other hand, running the models at a higher spatial resolution takes more time and resources. Therefore, potentially improved modelling results were discussed in a context of prolonged runtime. The case study consisted of two parts where a Digital Elevation Model, DEM of two meter resolution was implemented and compared to the five meter DEM that is currently in use. This was done by recreating previous flooding events by using discharge data from S-HYPE. In the first part, satellite data from Copernicus from two previous flooding events in Sweden were used for model validation in comparison with the results from inundation models of SMHI for the different DEM:s. An index was calculated to quantify the overlapping inundation areas. The events were at the river Emån in 2012 and at Västerdalälven in 2018. Moreover, the slope of the rivers within each study area was calculated to investigate correlation between improved flood modelling results for higher DEM resolution and slope of the rivers. The second part of the study investigated flood embankments for the two different DEM:s around Helige å river. A flooding event which took place in 2020 was recreated and the water flow around the built embankments was compared for the two resolutions.  Running the models, it turned out that simulations of several subcatchment areas were unstable with the two meter DEM, and could only be run with lower flow. The obtained results, however, revealed an improved inundation modelling for the DEM with a resolution of 2 m for all study areas in comparison to the data from Copernicus; however the runtime was increased by over 12 times. Moreover, the results also showed threshold effects, where the flooding was impeded by the flooding embankment with the two meter DEM but not at the lower resolution. Due to the stability issue and the limited scope of this study, it cannot be concluded whether SMHI should implement the two meter DEM in their flood warnings system. However, it was concluded that the stability has to be increased to make it feasible. It was also concluded that there are threshold effects between the two DEM:s and that the performance seems to increase overall for the higher resolution when it comes to precision of the modelling.

Höjddata är fundamentala inom en mängd applikationer. Genom att skapa en digital höjdmodell (DEM), d.v.s. en matematisk modell av terrängens fysiska form, kan höjddata nyttjas på ett effektivt sätt. Tillgång till digitala höjdmodeller underlättar både vid hållbar samhällsplanering och övervakning av klimatförändringar. Vid tillämpning av en DEM är det av största intresse att veta hur väl modellen representerar jordytan. Den centrala delen av studien innefattar en granskning av de två globala höjdmodellerna Copernicus GLO-30 DEM och FABDEM (Forest And Buildings removed Copernicus DEM) som jämförs med svenska referensmodeller baserade på nationella LiDAR-data (Light Detection And Ranging). Genom generering av en egen ytmodell från punktmolnet Laserdata NH framställdes referensdata för jämförelser med Copernicus GLO-30 DEM. Som referensdata för jämförelser med FABDEM användes GSD-Höjddata Grid 2+, vilket är ett markmodellsraster. Utvärderingen utfördes över tre provytor i Sverige. Dessa provytor representerar karaktäristiska marktyper inom landet. I granskningen av kvaliteten för de globala modellerna analyserades statistik för jämförelserna. Dessutom skapades plottar för att kunna visualisera höjdskillnaderna. Studien innehåller även en litteraturstudie om hur de globala modellerna har skapats. Skaparna av Copernicus GLO-30 DEM garanterar en utvidgad standardosäkerhet med täckningsgraden 90% (LE90) på 4 m. Den här studien resulterade i lite högre utvidgade osäkerheter, mellan ca 4,3 och 6,1 meter. Den lägsta osäkerheten uppnåddes i provytan över Stockholm som innehåller höga byggnader, vatten och en del vegetation. De mest avgörande avvikelserna för FABDEM kan kopplats till svagheter i metoden att framställa en markmodell från ytmodellen Copernicus GLO-30 DEM, men FABDEM påverkas också signifikant av brister i den underliggande modellen, d.v.s. i Copernicus GLO-30 DEM. / Elevation data is fundamental in a variety of applications. By creating a digital elevation model (DEM), i.e. a mathematical model representing the physical shape of the surface of the Earth, altitude data can be used effectively. Access to digital elevation models facilitates both sustainable spatial planning and monitoring of climate change. When applying a DEM, it is of greatest interest to know how well the model represents the earth's surface. The central part of the study includes a review of the two global height models Copernicus GLO-30 DEM and FABDEM (Forest And Buildings removed Copernicus DEM), which are compared with reference models based on Swedish national LiDAR data (Light Detection And Ranging). By generating its own surface model from the point cloud Laserdata NH, reference data was produced for comparisons with Copernicus GLO-30 DEM. GSD-Elevation data Grid 2+, which is a terrain model in grid format, was used as reference data for comparisons with FABDEM. The evaluation was performed over three test areas in Sweden. These test areas represent characteristic land types within the country. In the review of the quality of the global models, statistics for the comparisons were analysed. In addition, plots were created to be able to visualize the height differences. The study also includes a literature study on how the global models have been created. The creators of the Copernicus GLO-30 DEM guarantee an extended standard uncertainty at 90 % coverage probability (LE90) of 4 m. This study resulted in somewhat larger expanded uncertainties (90 %), between about 4.3 and 6.1 meters. The lowest uncertainty was achieved in the sample area over Stockholm, which contains tall buildings, water and some vegetation. The most significant deviations for FABDEM can be linked to weaknesses in the method of producing a terrain model from the surface model Copernicus GLO-30 DEM, but FABDEM is also significantly affected by the deficiencies in the underlying model, i.e. in Copernicus GLO-30 DEM.