Gegenstand dieser Arbeit ist die Forschungsdisziplin, welche in der Strukturmechanik als Modellordnungsreduktion bekannt ist. Im Mittelpunkt stehen Kopplungsprozesse von starren und elastischen Mehrkörpersystemen - sowohl in theoretischer Hinsicht als auch bezüglich der praktischen Realisation im Rahmen des Finite-Elemente-Programms ANSYS und des Mehrkörpersimulationsprogramms SIMPACK. Eine Vielfalt von strukturerhaltendenMOR-Methoden wurde zum Zwecke des Überblicks dargestellt. Darüber hinaus findet sich eine Kategorisierungsmethodik in Hinsicht auf den später beschriebenen FEM-MKS-Kopplungsprozess. Die Effizienz der MOR-Methoden wird sowohl hinsichtlich der Qualität der ROM als auch bezogen auf die hierfür benötigte Rechenzeit bemessen. Aus diesem Grunde wurden etliche MOR Schemata dargelegt, mit dem Ziel, den Effizienzfaktor während der Berechnung eines ROMs zu maximieren, das heißt maximale Qualität und minimale Rechenzeit zu erzielen. Die Validierung der dynamischen ROM-Eigenschaften basiert auf der Anwendung der sogenannten Modellkorrelationskriterien. Dies wurde an vier Anwendungsbeispielen aus dem Feld der Strukturmechanik getestet: der 3D-Balkenstruktur, der UIC60-Schiene, dem Pleuel und der Kurbelwelle. Die Anwendung der diagonal perturbation-Methodik verbessert die Kondition der Steifigkeitsmatrix eines Modells, von beiden Arten von Lösungsprozeduren, d.h. direkte und iterative Verfahren, betroffen sind. Die dynamische Bewegung mechanischer MKS wird als ein Index-3-DAE-Systemformuliert und die Information über die elastischen Körper wird in Form der sogenannten Standard Input Datei in einen MKS-Code transferriert. Die Einführung des Back-projection-Ansatzes ermöglicht die weitere Verwendung bestimmter ROM-Typen, derren assoziierten physikalische Eigenschaften unangemessen definiert wurden. Zum Abschluss werden die theoretischen, modellierenden und numerischen Fortschritte der Arbeit resümiert und kombiniert im Sinne der Model Order Reduction Package Toolbox (MORPACK). Die Matlab-basierte MORPACK-Toolbox ermöglicht den FEM-MKS-Kopplungsprozess für die Verwendung von ANSYS und SIMPACK. Hierin sind ein Großteil der zuvor erläuterten Erweiterungen eingeschlossen. Mit Hilfe der zwei integrierten inneren MOR- und SID-Schnittstellen als auch der vier Anwendungsebenen wird der Import von freien oder eingespannten ROM in SIMPACK ermöglicht. / The research discipline referred to as the Model Order Reduction in structural mechanics is the topic of this Thesis. Special emphasis is given to the coupling process of rigid and elastic Multi Body Dynamics in terms of both the theoretical aspects and the practical realization within the environment of the commercial Finite Element and the Multi Body Systems software packages, ANSYS and SIMPACK respectively. In this regard, a variety of structure preserving Model Order Reduction methods is presented and a categorization methodology is provided in view of the later FEM-MBS coupling process. The algorithmic scheme of several of the MOR methods indicates the capability of generating qualitatively better Reduced Order Models than the standardized Guyan and Component Mode Synthesis approaches. The efficiency of a MOR method is measured in terms of both the quality of the ROM and the associated time required for the .computation Based on the application of the, so called, Model Correlation Criteria the efficiency of the MOR schemes is tested on four application examples originating from the area of structural mechanics, i.e. the 3D elastic solid bar structure, the UIC60 elastic rail, the elastic piston rod, and the elastic crankshaft model. Herewith, the superiority of alternative MOR schemes in comparison to Guyan or CMS methods is demonstrated in terms of the ROM?s quality and the computation time by the use of either the one-step or the two-step MOR algorithms. Numerous of the FE discretized structures suffer from the, so called, ill-conditioned properties regarding the associated stiffness matrix. On one hand, the direct solution of a MOR method might produce erroneous ROMs due to the associated truncation phenomenon and on the other hand, any kind of iterative approach suffers from vast computation times. The application of the diagonal perturbation methodology improves the condition properties of the model?s stiffness matrix and thus, both kinds of the aforementioned solution procedures are affected. The back-projection approach is introduced, which projects the ROM belonging to the Non physical subspace reduction-expansion methods category back onto the physical configuration space and thus, enabling its further usage in a MBS code, e.g. SIMPACK. Finally, the theoretical, modelling, and numerical advancements are combined in terms of the Model Order Reduction Package. The Matlab-based MORPACK toolbox enables the FEM-MBS coupling process for the ANSYS-SIMPACK utilization and herewith, several of the aforementioned enhancements are included. With the help of the two integrated inner interfaces, i.e. MOR and SID, as well as four application levels, the import into SIMPACK of alternatively free or fixed ROMs is enabled. The functionality of MORPACK is demonstrated based on two application examples, namely, the 3D elastic solid bar and the UIC60 elastic rail, the dynamic properties of which are validated prior to their import into SIMPACK.

Submitted by Luciclea Silva (luci@ufpa.br) on 2018-11-01T17:20:15Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese_EstadosligadosMajorana.pdf: 5157889 bytes, checksum: a697f1a4428dbb52f1b3046f7b793221 (MD5) / Approved for entry into archive by Luciclea Silva (luci@ufpa.br) on 2018-11-01T17:20:40Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese_EstadosligadosMajorana.pdf: 5157889 bytes, checksum: a697f1a4428dbb52f1b3046f7b793221 (MD5) / Made available in DSpace on 2018-11-01T17:20:40Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese_EstadosligadosMajorana.pdf: 5157889 bytes, checksum: a697f1a4428dbb52f1b3046f7b793221 (MD5) Previous issue date: 2018-10-11 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A pesquisa em física da matéria condensada com isolantes e supercondutores topológicos tem contribuído muito para a caracterização das propriedades de superfície e de modos zero em nanofios. Investigamos teoricamente o transporte de elétrons através do ponto quântico em forma de T (PQ) com um único nível e spinless, conectado a uma cadeia em zigue zague e acoplado a um supercondutor p-wave, utilizando o método analítico recursivo de funções de green no equilíbrio. Este modelo é uma extensão da cadeia de Kitaev para uma rede triangular de tamanho finito com três, quatro e cinco sitios. Observamos que modos zero de Majorana podem ser sintonizados através dos parâmetros de acoplamento do dispositivo e a condutância linear mostra ambos os Estados Ligados de Majorana (MBS) na fase topológica e na fase topológica geral maximamente robusta. Este modelo mais realista permite a detecção de MBS através do controle dos parâmetros que governam o tunelamento eletrônico e pode ser útil para experimentos relevantes. / The research in condensed matter physics with insulators and superconductors topological has contributed greatly to the characterization of the surface properties and modes zero in nanowires. We investigate theoretically, through the recursive Green’s function approach, the electron transport through the T-shaped quantum dot (PQ) with a single level and spinless, connected to a zigue zague chain and coupled to a p-wave superconductor. This model is an extension of the Kitaev chain for a network triangular of finite-size with for three, four, and five sites. We find that the Majorana zero modes can be tuned through the coupling parameters of the device and the linear conductance show both the Majorana Bound States (MBS) in topological phase and in the general topological phase maximally robust. This more realistic model allows the detection of MBS through of the control of the parameters governing the electronic tunneling and can be helpful for relevant experiments. Keywords: Majorana Fermions, recursive Green’s function approach, Kitaev chain, class of electronic nanodevices, Quantum Dot, T-shaped, Qubit, Majorana Bound States (MBS).

擔保房貸憑證(CMOs)是衍生自不動產抵押證券(MBS)的證券化商品，透過分券的特殊設計，藉此降低MBS商品的提前清償風險，也增加市場投資人的選擇彈性。但特殊的設計同時也提高了評價上的困難度，由於此產品的提前清償狀況會依分券性質與標的抵押貸款借款人的償還情形而有所不同，為了準確掌握CMOs商品的現金流量，必須採用較為充分的貸款資料與提前清償模型來推估提前清償機率。本文採用競爭風險模型來做為提前清償模型，透過較多變數的選擇方式，模擬出較為精確的提前清償機率路徑。 此外，BGM利率模型是透過將利率間斷化，捕捉市場上可觀察到的利率，同時也可提供在不同時點下的即期利率，可藉此推算出不同時點下的分券價格，故採用BGM來做為本文的利率模型。

The link suspension is the most prevailing suspension system for freight wagons in Central and Western Europe. The system design is simple and has existed for more than 100 years. However, still its characteristics are not fully understood. This thesis investigates the dynamic performance of freight wagons and comprises five parts: In the first part a review of freight wagon running gear is made. The different suspension systems are described and their advantages and disadvantages are discussed. The second part focuses on the lateral force-displacement characteristics of the link suspension. Results from stationary measurements on freight wagons and laboratory tests of the link suspension characteristics are presented. To improve the understanding of various mechanisms and phenomena in link suspension systems, a simulation model is developed. In the third part the multibody dynamic simulation model is discussed. The previous freight wagon model developed at KTH is able to explain many of the phenomena observed in tests. In some cases, however, simulated and measured running behaviour differ. Therefore, a new simulation model is presented and validated against on-track test results. The performance of standard two-axle freight wagons is investigated. The most important parameters for the running behaviour of the vehicle are the suspension characteristics. The variation in characteristics between different wagons is large due to geometrical tolerances of the components, wear, corrosion, moisture or other lubrication. The influence of the variation in suspension characteristics and other parameters on the behaviour of the wagon, on tangent track and in curves, is discussed. Finally, suggestions for improvements of the system are made. A majority of the traffic related track deterioration cost originates from freight traffic. With heavier and faster freight trains the maintenance cost is likely to increase. In the fourth part the possibility to improve ride comfort and reduce track forces on standard freight wagons with link suspension is discussed. The variation of characteristics in link suspension running gear is considerable and unfavourable conditions leading to hunting are likely to occur. Supported by on-track tests and multibody dynamic simulations, it is concluded that the running behaviour of two-axled wagons with UIC double-link suspension as well as wagons with link suspension bogies (G-type) can be improved when the running gear are equipped with supplementary hydraulic dampers. Finally in the fifth part the effects of different types of running gear and operational conditions on the track deterioration marginal cost — in terms of settlement in the ballast, component fatigue, wear and RCF — is investigated. Considerable differences in track deterioration cost per produced ton-km for the different types of running gear are observed. Axle load is an important parameter for settlement and component fatigue. Also the height of centre of gravity has significant influence on track deterioration, especially on track sections with high cant deficiency or cant excess. / QC 20100802

This master thesis, concentrated on crank train mechanism of diesel V6 engines with special focus on design and construction of crankshaft, is divided in two main phases. First phase is concept, which contains brief introduction of diesel V-engines construction, parameters of chosen engine unit, especially crank train mechanism, design of crankshaft and 1D analysis of torsional vibrations. Second phase is layout, this phase deals with MBS 3D analysis with flexible FEM models of crankshaft and engine block. These outputs are used for fatigue analysis of crankshaft.

This thesis deals with comparison of straight four-cylinder petrol engine with a displacement of 1,5 litres and its three-cylinder alternative, which is based on a four-cylinder. The thesis starts with a research, where are examples of some currently manufactured engines. The research is followed by design of both engines, where the design of the crank mechanisms is made more in detail. After that, both crank mechanisms are subjected to dynamic analysis using FEM and MBS methods. The thesis ends with comparison of both engines in terms of crankshaft load, mass and dimensions.

is diploma thesis deals with design concept of two-seater sports car with the main focus on chassis torsional stiffness and axle kinematics. The main idea started with some paper sketches which were later transferred to the 3D model with all the main parts (engine, differential, driver etc.) using CATIA V5 design program. Then the torsional stiffness was counted using FEM software ANSYS 12.0. Finally the axis geometry during bump/rebump movement of the wheel was simulated in MBS system ADAMS 2007.

The main purpose of this diploma thesis is the experimental vehicle Formula Faster engine reconstruction. The current Ford Kent 1600cc engine will be replace by the Škoda 1.4 MPI engine. The next task is to analyse kinematic properties of the front axle and subsequent optimization and transformation of steering rod placing which relates to wheel toe and bump travel. The last part is concerned with steering wheel mounting transformation, concretely with reconstruction to obtain removable steering wheel using rapid coupling.

Diploma thesis deals with the dynamic analysis of OHV pushrod valve train drive of the old-new conception of 6-cylinder tractor engine with 24 valves made by Zetor Tractors, a.s.. There is a requirement to create an analytical model and design valve springs for the engine. The work also points to the current analytical methods of appropriate simulation software used in automotive industry.

This diploma thesis studies the use of air springs for race car, precisely Formula Student race car. Research part of the thesis deals with choosing suitable air spring for given application. In practical part, there is computation of parameters for appropriate setting of air spring, so it will comply with the rules of Formula Student. There is also simulation of air spring functionality in real use.