This thesis is concerned with the design of Formula SAE rear axle suspension and spring suspension. First part of the thesis deals with the preliminary desing and is followed by the kinematic analysis and optimalization of the rear axle geometric ordering. Next part is related to the verification of the spring suspension characteristics. Both these parts were worked up with the aid of the software ADAMS. Last part of the thesis includes the engineering desing of rear axle components and stress and deformation analysis.

This master thesis deals with wheel set axles of rail vehicles, their design and methods of implementation stress analysis. In this work, I created a powered locomotive wheel set: axle and wheel. For the purpose of the design department of the Bonatrans Group a.s. company I developed an analytical solver, which allows creating stress analysis, which will be used for verifying finished design and in addition it allows printing of stress analysis as report for the railway´s offices. Next step was a stress analysis of this design of axle in this analytical solver.

This diploma thesis deals with the experimental study of the influence of operating conditions on the tribological aspects of the wheel flange and rail gauge contact. The wheel flange contact occurs when the vehicle moves on a curve track and it leads to severe up to catastrophic wear regime. For effective reduction of wear is important to apply a suitable amount of lubricant at appropriate intervals into the contact. The issue in this work comprehensively studies using of three laboratory apparatus and six methods that are theoretically and experimentally compared. Assessed are friction, wear, distribution and film thickness of lubricants for different contact conditions. The resulted amount of lubricant and interval of its application eliminates development of seizure at low consumption of lubricant. The understanding of mechanisms that occur in the wheel-rail contact not only helps to reduce operating costs and improved to energy efficiency of movement of vehicle on a track, but it is the basis for safe, reliable and ecological operation of rail transport.

The document deals inspecting forces of the structure. The task of diploma thesis is analyze the crane load and chech up the stress of steel construction. Perform stress analysis forwarding bridge of bucket-wheel excavator by using finite element method. Further assess the consequences resulting from the design modifications. The project was carried out with cooperation with NOEN, a.s.

Due to a need of more compact bogies, the brake discs can be mounted on the railway wheels, bolted through the wheel web. Thus, the wheels are drilled and have multiple areas of contact with the brake discs. To establish maintenance procedures that will be applied to the  wheels,  SNCF  used  the  feedback  from  experience  (as  with  the  train  AGC)  which  gives  perfect  performance  in  terms  of  safety.  However,  to  optimize  the  maintenance  process, numerical  simulations  may  be  preferred  since  they  are  less  conservative.  This  report  describes  the  numerical  simulations,  based  on  the  finite  element  method,  that  were conducted to determine if the Régiolis wheel complies with the standard EN 13979-­‐1 from a mechanical  fatigue  point  of  view.  In  addition,  it  provides  additional  insights  regarding  the  loads and damage suffered by the wheel, which are not taken into account in the standard: the  damage  induced  by  disc  braking  and  the  fretting  that  may  occur  at  the  contact  interfaces. This study has been used as a decision support for the first inspection intervals of the Régiolis wheels.

Energy recovery ventilation (ERV) systems are designed to decrease the energy consumed by building HVAC systems. ERV’s scavenge sensible and latent energy from the exhaust air leaving a building or space and recycle this energy content to pre-condition the entering outdoor air. A few studies found in the open literature are dedicated to developing detailed numerical models to predict or simulate the performance of energy recovery wheels and desiccant wheels. However, the models are often computationally intensive, requiring a lot of time to perform parametric studies. For example, if the physical characteristics of a study target change (e.g., wheel diameter or depth) or if the system runs at different operating conditions (e.g., wheel rotation speed or airflow rate), the model parameters need to be recalculated. Hence, developing a mapping method with better computational efficiency, which will enable the opportunity to conduct extensive parametric or optimal design studies for different wheels is the goal of this research. In this work, finite difference method (FDM) numerical models of energy recovery wheels and desiccant wheels are established and validated with laboratory test results. The FDM models are then used to provide data for the development of performance mapping methods for an energy wheel or a desiccant wheel. After validating these new mapping approaches, they are employed using independent data sets from different laboratories and other sources available in the literature to identify their universality. One significant characteristic of the proposed mapping methods that makes the contribution unique is that once the models are trained, they can be used to predict performance for other wheels with different physical geometries or different operating conditions if the desiccant material is identical. The methods provide a computationally efficient performance prediction tool; therefore, they are ideal to integrate with transient building energy simulation software to conduct performance evaluations or optimizations of energy recovery/ desiccant wheel integrated HVAC systems.

For testing of OTR (Off-The-Road) tires for dump trucks during development, radial loads are applied between the tested tire and a rotating roller drum by using a parallel kinematic wheel guide unit. Additional lateral loads are created by setting a slip angle. The bolt connection between rim and test bench axle must be able to transmit the occurring forces and moments fatigue endurable. Three different procedures for evaluating the bolt connection are compared: Purely analytical evaluation as well as manual and automated evaluation of FEA results. Thereby the frictional connection in the joint and the bending moments in the bolts, resulting from elastic deformation of the components, are identified as the most critical factors. It is shown how these factors are considered in the individual methods and what causes differences in the calculation results. Using various optimization approaches, the bolt connection is designed for fatigue strength. / Zur entwicklungsbegleitenden Erprobung von OTR (Off-The-Road) Reifen für Muldenkipper werden an einem Prüfstand mittels einer parallelkinematischen Radführungseinheit Radialkräfte zwischen dem zu prüfenden Reifen und einer rotierenden Laufrolle aufgebracht. Durch Einstellung eines Schräglaufwinkels entstehen zusätzlich Seitenführungskräfte. Der Schraubverband zwischen Radfelge und Prüfstandsachse muss die auftretenden Kräfte und Momente dauerfest übertragen können. Es werden drei verschiedene Vorgehensweisen zur Bewertung des Schraubverbands gegenübergestellt: Rein analytische Auswertung sowie manuelle und automatisierte Auswertung von FE-Ergebnissen. Dabei werden der Reibschluss in der Trennfuge sowie Biegemomente in der Schraube, resultierend aus der elastischen Verformung der Bauteile, als die kritischsten Faktoren identifiziert. Es wird gezeigt, wie diese Größen in den einzelnen Verfahren berücksichtigt werden und worauf Unterschiede in den Berechnungsergebnissen zurückzuführen sind. Unter Anwendung verschiedener Optimierungsansätze wird der Schraubverband auf Dauerfestigkeit ausgelegt.

Ein zentraler Nachteil der meisten Koordinationspolymere ist, dass sie elektrische Isolatoren sind. In dieser Arbeit wurden konjugierte Koordinationspolymere auf ihre Leitfähigkeit untersucht, die eine Rhodium-Paddle-Wheel-Struktur besitzen. Die Beschichtung auf einer funktionalisierten Oberfläche im Vorfeld der C-AFM-Messung wurde mittels eines selbstgebauten Dip-Coaters realisiert. Koordinationspolymere, die das [Rh2(ac)4]-Paddle-Wheel enthalten, sind unabhängig von den untersuchten Linkern Isolatoren. Werden die Acetatliganden mit drei oder vier Acetamidatliganden ausgetauscht, so ist das entstandene Koordinationspolymer leitfähig. Temperaturabhängige C-AFM-Messungen ergeben eine für hohe Feldstärken konstante Aktivierungsenergie, die je nach Koordinationspolymer zwischen 0,3 eV und 0,7 eV beträgt. Anhand der Ergebnisse wurde gezeigt, dass der Ladungstransport durch einen Hopping Mechanismus dominiert wird. C-AFM ist eine aussagekräftige Methode zur Charakterisierung leitfähiger Koordinationspolymere auf der Oberfläche.

In this thesis the requirements for a rear wheel steering mechanism aimed to be implementedon KTH:s Formula Student car were evaluated. The requirements were obtainedby using already known loads, an analysis of how the quickly the driver turns the steeringwheel during track driving from video material and the Formula Student rulebook whichthe car is designed after. After the requirements were produced a number of concepts wereproduced and evaluated against each other. The concept that was given the highest scorewas a rack and pinion concept with a rotary actuator which was developed further.The design was made by first selecting an actuator with a planetary gearbox that couldfulfill the speed and load requirements and afterwards with CAD a design that could beintegrated on the car was made. The concept weighed around 1,7 kg and was compatiblewith the requirements. / I detta arbete undersöktes kraven som ställs på ett bakhjulsstyrningssystem för implementering på KTH:s Formula Student bil. Kraven togs fram genom att använda redan kända laster, en analys av hur snabbt föraren svänger utifrån videomaterial samt regelboken som alla formulastudentbilar är konstruerade efter. Efter att kraven tagits fram utvärderades ett antal koncept där det bästa konceptet, kuggstångsmekanism med ett roterande ställdon utvecklades vidare. Prototypdesignen gjordes genom att först välja ett ställdon med planetväxellåda som skulle klara av kraven och därefter med hjälp av CAD skapa en integrerbar design. Det färdiga konceptet väger ca 1,7 kg och klarar alla ställda krav.

During the last 10 years, low pressure carburizing and high pressure gas quenching has become more popular since it is a “new” process and researchers reports that the distortion characteristics gained from these processes is improved in relation to conventional processes. The aim of this work was to investigate the distortions gained from three different heat treatment processes on main shaft gears and crown wheels. Experiments with atmospheric carburization with oil quenching and low pressure carburization with nitrogen gas quenching or oil quenching were made and distortion characteristics gained from these processes were then measured and compared. It was found that components treaded in the relatively new LPC-HPGQ process are similar and often even better than the conventional method. The larger main shaft gear improves the most with newer method but instead gets a lower core hardness and systematic diametrical shrinkage. Some measurements on the crown wheel were also improved but others were affected negatively.