In this work the influence of Under Sleeper Pads on the dynamic forces on a railway track is investigated. A special interest is devoted to the effect of using Under Sleeper Pads in a railway track with changing vertical stiffness. The contact force between wheel and rail and the ballast contact forces are examined. For the investigation a finite element model with the length of thirty sleepers is created and calculations are performed with the software LS-DYNA. Three different cases of varying vertical track stiffness are studied: the transition from an embankment to a bridge, a randomly varying track stiffness along the railway track and hanging sleepers.

<p>In this work the influence of Under Sleeper Pads on the dynamic forces on a railway track is investigated. A special interest is devoted to the effect of using Under Sleeper Pads in a railway track with changing vertical stiffness. The contact force between wheel and rail and the ballast contact forces are examined. For the investigation a finite element model with the length of thirty sleepers is created and calculations are performed with the software LS-DYNA. Three different cases of varying vertical track stiffness are studied: the transition from an embankment to a bridge, a randomly varying track stiffness along the railway track and hanging sleepers.</p>

This research systematically investigates the sleeper effect, a counterintuitive phenomenon in which attitudes toward a persuasive message increase in favourableness over time despite the presence of discounting information. The sleeper effect has rarely been researched since criticisms in the 1970s and 1980s concerning relevance and difficulty in demonstrating the effect. Shifts in the consumer environment, however, merit a re-examination of the effect. The paucity of research leaves major gaps in establishing the conditions for existence of the sleeper effect, understanding the underlying mechanisms of the effect, the context in which the sleeper effect may flourish, and other factors with the potential to influence the effect. Recent research suggests self-associations at encoding impacts information processing and attitude change. The research reported in this thesis builds on the latter to develop hypotheses to test the relationships between self-associations and attitudes toward positive and negative information over time. The study adopts a quantitative approach to test the hypotheses using a series of three experiments, each building on one another. The first experiment seeks to find the absolute sleeper effect, and accomplishes this aim. The second experiment investigates the role of implicit self-anchoring on attitudes toward positive and negative information over time, showing that self-anchoring influences self/product identity overlap rather than the transfer of meaning through elaborative associations. The third experiment compares implicit self-anchoring and explicit self-referencing on attitudes toward positive and negative information, and shows that explicit self-referencing produces the associations and dissociations necessary to find the sleeper effect. This study significantly contributes to understanding the sleeper effect, not only by providing evidence for its existence, but by clarifying the mechanisms at work in the sleeper effect process. It distinguishes implicit self-anchoring and explicit self-referencing, and defines two processes in which the self and object interact in memory to influence attitudes. From a practical perspective, it situates the research in the contemporary consumer context, in which positive and negative information regarding products and services is accessible to consumers online. This study demonstrates that negative information can be leveraged to produce positive attitudes.

Railway sleepers have important roles in the complex railway system. Due to different loading condition, poor maintenance of sleeper or bad quality of ballast, a random load distribution along the sleeper-ballast interface may occur. A sleeper design, and also the track system design, which do not consider the random load distribution, could influence the performance of the sleeper and even damage the whole railway system. Thus, a numerical static and dynamic analysis for a pre-stressed concrete mono-block railway sleeper is carried out using finite element method. The structural behaviour of a single sleeper subjected to a random sleeper-ballast interaction is studied in three steps. First, four typical scenarios of support condition for sleeper are discussed in numerical analysis. Second, large enough numerical results under different random support conditions are conducted. Finally, Neural Network methodology is used to study the performance of sleeper under a stochastic support condition. Results of vertical displacement of rail seat, tensile stress at midpoint and underneath rail seat are presented. Moreover, the worst support condition is also identified.

The manufacturing process ‘long line method’ has shown many advantages when producing prestressed concrete sleepers, such as rapid production and low cost. However, there have been certain difficulties when cutting the 100 m long concrete blocks into sleepers. The sleepers tend to crack when the diamond cutting blade cuts through the last strands. Moreover, the shape and size of the cracks varies from one sleeper to another. Although these cracks may not affect the load carrying capacity, they will not be aesthetically pleasing. No earlier studies within the area have been found, i.e. diamond cutting of prestressed concrete blocks. As a result, there have been certain difficulties when approaching the problem. Finite element analysis has been proven to be a useful tool when analyzing stress variation. Throughout this project, the cutting simulation has been analyzed using the finite element analysis software ABAQUS. To summarize, stress variation has been examined during different cutting depths. The results from the FE model shows that no critical values were reached in the areas expected to have cracks. The true cause of the problem could not be specified. Therefore, further studies are needed yet this thesis could be a good foundation.

This diploma thesis is focused on experimental measurement and acoustic and dynamic behavior analysis of railway construction with the Y – steel sleepers and their comparison with concrete sleepers. The measurements were taken in situ, in suitable sections of a railway line. These sections meet the requirements of regional railway tracks in the Czech Republic. Monitored parameters were obtained by measuring a response of testing trains and were analyzed using frequency and time analysis. Based on these evaluations, comparisons of particular constructions and their recommendations for practice were made.

The diploma thesis applies to under sleeper pads. It researches thein using and benefits in foreign railvway authorities. Further it assesses track geometrical parameters in the trial track section with under sleeper pads in track Havlíčkův Brod - Okrouhlice and in the railway station Planá nad Lužnicí. There were evaluated measurements of vertical alingnment rails by precise leveling and deviations of track geometrical parameters measured by track meusuring car in the diploma thesis.There is expressed an conclusion about the impact of under sleeper pads on track geometric data in the thesis.

(in English): The thesis deals with the exploration of the possible influence of so-called sleeper effect in perception of fake news for teenagers. In the first part this thesis explains the historical and research context of both sleeper and the illusory truth effect, which also served as an inspiration for research design, and this part also describes the type of news and the present state of news trushworthiness in the Czech republic. The theoretical part also describes the basic methods of quantitative research and statistical analysis that are later on applied in the practical part of the thesis, which mainly includes the final data analysis and the repeated research that went on during May and June 2019 at 6 chosen schools.

No description available.

Thesis (M.A.)--University of Delaware, 2008. / Principal faculty advisor: Margaret Marie Lidz, Winterthur Program in Early American Culture. Includes bibliographical references.