Master´s thesis deals with design of four cylinder race engine for rally application with requirement of small construction weight, by using specific Super 2000 regulations. Calculation analysis is mainly focused on crankshaft stress analysis and torsion vibration.

Numerical procedures for reliable wheel and rail wearprediction are rare. Recent development of simulationtechniques and computer power together with tribologicalknowledge do however suggest computer aided wear prediction.The objective of the related research field at the RoyalInstitute of Technology (KTH) is to arrive at a numericalprocedure able to simulate profile evolution due to uniformwear to a degree of accuracy sufficient for application tovehicle dynamics simulation. Such a tool would be useful formaintenance planning as well as optimisation of the transportsystem and its components. The research contribution accounted for in this thesisincludes, in addition to a literature review, refinement ofmethods applied to uniform wheel wear simulation by inclusionof braking and improvement of the contact model. Further atentative application to uniform rail wheel simulation has beenproposed and tested. The first part addresses issues related to braking andwheel-rail contact conditions in the context of wheel wearsimulation. The KTH approach includes Archard’s wear modelwith associated wear maps, vehicle dynamics simulation andrailway network definition. In previous work at KTH certainvariations in operating conditions have been accounted forthrough empirically estimated average scaling factors. Theobjective of the current research is to be able to include suchvariations in the set of simulations. In particular theinfluence of disc braking and varying friction and lubricationconditions are investigated. Both environmental factors likemoist and contamination and deliberate lubrication need to beconsidered. As part of the associated contact analysis theinfluence of tangential elastic deformation of the contactingsurfaces on the sliding velocity has been separatelyinvestigated and found to be essential in case of partial slipcontact conditions. In the second part validation of the improvements related towheel wear simulation is addressed. Disc braking has beenincluded in the simulation set and a wear map for moist contactconditions based on recent tribometer tests has been draftedand tested. It has been shown that the previously used brakingfactor accounts for the combination of the contributions fromsurface elasticity and braking. Good agreement withmeasurements from the Stockholm commuter service is achieved.It is concluded that the model improvements accounted for aresufficient for adequate simulation of tread wear but thatfurther development of the flange / gauge corner contactmodelling may be needed. In the final part a procedure for simulation of rail wearand corresponding profile evolution has been formulated. Asimulation set is selected defining the vehicles running on thetrack to be investigated, their operating conditions, andcontact parameters. Several variations of input data may beincluded together with the corresponding occurrenceprobability. Trial calculations of four non-lubricated curveswith radii from 303 m to 802 m show qualitatively reasonableresults in terms of profile shape development and difference inwear mechanisms between gauge corner and rail head. The wearrates related to traffic tonnage are however overestimated. Itis believed that model refinements in terms of environmentalinfluence and contact stress calculation are useful to improvethe quantitative results. / QC 20100531

The goal of this thesis work is to evaluate and quantify the advantages and disadvantages of Active Rear Steering (ARS). The evaluation is carried out through Multi-Body System (MBS) simulations. An analytical model has been developed to better understand the basic dynamics of vehicles equipped with rear steering. In parallel, a high fidelity MBS model is developed in Simpack. This model includes suspension kinematics and compliance, allowing for detailed analyses of steering hardware performance. Next, different control strategies aiming at improving manoeuvrability, stability and agility are implemented in Simulink. In order to assess their effectiveness, the high fidelity model is utilised by running co-simulation with Simulink. Manoeuvrability is assessed through constant steer, constant radius and ramp steer manoeuvres. Stability is assessed through transient manoeuvres such as step steer and sine with dwell. Agility is assessed through step steer and frequency response. Ultimately, also a subjective assessment is carried out by means of Volvo Cars' dynamic driving simulator. The conclusion from the assessment is that the drivers feel the all wheel steered vehicle more stable during evasive manoeuvres. It is concluded that for manoeuvrability the minimum turning radius is reduced by 19 % at low velocity; this implies that the steering angle request is reduced at low velocity, while it is increased at high velocity. A slightly higher steering angle request at high velocity might be beneficial since the driver would be able to control the vehicle in a wider range of steering wheel angles. For agility the results are contradicting: on the one hand, according to the step steer rise time difference between lateral acceleration and yaw rate, the controlled vehicles are performing worse than the passive vehicle; on the other hand, according to the frequency response analysis, both the delays between steering input and yaw rate and between lateral acceleration and yaw rate are reduced up to respectively 75 % and 46 % for the considered frequency range. Finally, for stability, the yaw rate overshoot from a step steer can be reduced up to 65 % at high velocity and the sideslip angle can always be reduced. The vehicle equipped with ARS outperforms the passive vehicle in the sine with dwell manoeuvre. / Målet med detta examensarbete är att utvärdera och kvantifiera fördelarna och nackdelarna med Active Rear Steer (ARS) för Volvo Cars. Utvärderingen utförs genom Multi-Body System (MBS) simuleringar. En analytisk modell har utvecklats för att bättre förstå den grundläggande dynamiken i fordon utrustade med bakhjulsstyrning. Parallelt utvecklades en MBS-modell med hög precision i Simpack. Denna modell inkluderar hjulupphängningens kinematik och eftergivlighet, vilket möjliggör detaljerade analyser av styrhårdvarans prestanda. Därefter implementeras olika kontrollstrategier som syftar till att förbättra manövrerbarhet, stabilitet och agilitet i Simulink. För att bedöma deras effektivitet används MBS-modellen för att köra co-simulering med Simulink.Manövrerbarhet bedöms genom konstant styrning, konstant radie och rampstyrning. Stabilitet bedöms genom transienta manövrar som stegstyrning och sinus med fördröjning. Agilitet bedöms genom stegstyrning och frekvensrespons. Slutligen görs också en subjektiv bedömning med hjälp av Volvo Cars dynamiska körsimulator. Slutsatsen från bedömningen är att förarna anser att fordonet upplevs vara mycket stabilare vid undanmanövrar. Vidare är slutsatsen att för manövrerbarhet minskar den minsta svängradien med 19 % vid mycket låg hastighet; detta innebär att styrvinkel reduceras vid låg hastighet, medan den ökar vid hög hastighet. En något högre styrvinkeln kan vara fördelaktig eftersom föraren skulle kunna styra fordonet i ett större rattvinkelområde. För agilitet är resultaten motsägelsefulla: å ena sidan, enligt stegstyrningstidsskillnaden mellan lateral acceleration och girhastighet, fungerar de aktiva fordonen sämre än det passiva fordonet; å andra sidan, enligt frekvensresponsanalysen, reduceras både fördröjningarna mellan girhastighet och styrvinkel och mellan lateral acceleration och girhastighet upp till ungefär 30 %. Slutligen, för stabilitet, kan girhastighetens översläng från en stegstyrning minskas upp till 65 % vid hög hastighet och avdriftsvinkeln kan alltid minskas. Fordonet som är utrustat med ARS överträffar det passiva fordonet i manövern sinus med fördröjning.

本論文將針對不同證券化標的型態和考量房貸戶提前清償差異之情況下，來推導MBS的評價公式。其中可發現任何證券化標的型態的MBS評價過程都能從可調整利率住宅抵押貸款的角度來進行，因此建構出的一般化評價模型便可作為其他新奇房貸設計的參考依據。並且透過蒙地卡羅法來模擬可調整利率住宅抵押貸款的理論價值，同時採用反向變異法來達到加速模擬過程的目的，以便於更趨近於真正的理論價值。而且也針對建構模型中的各項參數、誘因函數參數以及其他影響MBS理論價值的因素進行敏感度分析。

The work seeks to analyze the causes and impacts of the current financial crisis. It deals with the theoretical view and definition of financial crisis, along with a brief historical excursion. A significant part of the work is devoted to describe the financial crisis in the United States and in selected, economically important, countries. In the context of the causes of and solutions to the current crisis period are remembered views of different economic schools, which are very different. A significant part is devoted to the description of institutional architecture and function of the financial system. Important part is the description of the functioning of lending money (such interest and regulatory policy), because the author sees in it a long series of "unhealthy" factors, which helped the emergence of a financial crisis. The aim of this work is to give a komplete, non-ideological coloring, look at the biggest financial crisis in modern history.

The goal of this diploma thesis is to design the journal bearings for high pressure diesel pump which is part of Common rail system from Motorpal Company. This producer is also submitter of this diploma thesis and as a result it is expecting the reduction of cost price and possible transfer to the diesel oil lubrication. Firstly, there is sum up of issues of high pressure pump by Motorpal. The next part of the thesis describes the journal bearings and its construction, tribology of the journal bearings and also the overview of the materials. These materials are currently being used for securing long time usage and do not require service maintenance during lifespan period. In the practical part there is applied the Multy Body System (MBS) approach with rigid bodies and after that there are used analytic relations, which however do not include impact of movement of the journal center during dynamic stress. The thesis concludes with a comparison of results of both calculations and determination of bearing parameters, which according to the calculations ensure an achievement of hydrodynamic lubrication.

The aim of this thesis is an analysis of the construction of a trailer used for transporting concrete pillars. The main part of the thesis is focused on frame construction. For the calculation of load states a multi body system was used, whereby a simulation of transport in terrain was performed. The results from these calculations will be used as limiting conditions for strength control. The method of solution is the finite element method. All acquired results will be analysed and according to them changes will be made to the frame construction. In addition to this, the thesis contains drawings documenting the above-mentioned changes.

This diploma thesis deals with the solution of the trailer frame Variant 350 for transport of cable reels. The aim of this work is to drive a dynamic simulation of a cable lift generated by the track and in specific places to find this track burdensome conditions that affect the design of the frame. According to these states gained strenght to control the finite element method, implement and then modify the design and then create construction drawings prepared.

The wheel-rail contact is at the core of all research related to vehicle-track interaction. This tiny interface governs the dynamic performance of rail vehicles through the loads it transmits and, like any high stress concentration zone, it is subjected to serious damage phenomena. Thus, a clear understanding of the rolling contact between wheel and rail is key to realistic vehicle dynamic simulation and damage analyses. In a multi-body-system simulation package, the essentially demanding contact problem should be evaluated in about every millisecond. Hence, a rigorous treatment of the contact is highly time consuming. Simplifying assumptions are, therefore, made to accelerate the simulation process. This gives rise to a trade-off between accuracy and computational efficiency of the contact models in use. Historically, Hertz contact solution is used since it is of closed-form. However, some of its underlying assumptions may be violated quite often in wheel-rail contact. The assumption of constant relative curvature which leads to an elliptic contact patch is of this kind. Fast non-elliptic contact models are proposed by others to lift this assumption while avoiding the tedious numerical procedures. These models are accompanied by a simplified approach to treat tangential tractions arising from creepages and spin. In this thesis, in addition to a literature survey presented, three of these fast non-elliptic contact models are evaluated and compared to each other in terms of contact patch, pressure and traction distributions as well as the creep forces. Based on the conclusions drawn from this evaluation, a new method is proposed which results in more accurate contact patch and pressure distribution estimation while maintaining the same computational efficiency. The experience gained through this Licentiate work illuminates future research directions among which, improving tangential contact results and treating conformal contacts are given higher priority. / <p>QC 20130911</p>

Tato diplomová práce byla psána při studentské zahraniční stáži, pod záštitou Evropské Unie – program „ERASMUS Student Mobility for Placement“. Stáž byla absolvována mezi prosincem 2010 a květnem 2011 ve společnosti a.d.Tramontana, mající sídlo v Palau de Santa Eulália, Španělsko. Pro kompletní návrh podvozku a odpružení jakéhokoli vozidla je nezbytná znalost mnoha technických disciplín. Tato diplomová práce se zabývá dvěma z nich – odpružení a řízení. Nejprve je rozebrána teorie, na kterou se může navázat v praktické části práce. Velká pozornost byla věnována srozumitelnosti textu a názornosti obrázků, bez zbytečných detailů, avšak bez vynechání důležitého. Tuto práci je tedy možné užít jako prvního kroku před návrhem podvozku. V další části je popsáno, jak byla probraná teorie využita při návrhu řízení u skutečného vozu, přičemž největší pozornost je věnována Ackermannově teorii řízení a geometrii zabraňující samořízení při propružení. V závěrečných částech je pozornost věnována ukázce některých z každodenních činností v malosériové výrobě automobilů – jde o zjištění maximálně možného pohybu kola při propružení a proces výroby příčných trojúhelníkových ramen včetně návrhu jejich připevnění k šasi.