No description available.

The purpose of this research is to analyze the use of the public train usage in Central Florida to determine the feasibility of high-speed rail usage in the future. This study will be split into parts and expanded upon. The first part will observe rider perspective, values, and issues regarding rail transportation as is available in Central Florida. In further installations, which will be conducted separately from this thesis, there will be an analysis of the providers of rail transportation. It is hypothesized that there will be a moderate demand for rail transportation used by the public. Original: The main purpose of this descriptive research is to describe the feasibility of high speed rail in the United States. Feasibility is defined as the determining factor in the sustainability of a project. In the case of this research study, high speed rail is the project and is defined as a specialized railroad system, including dedicated tracks and specialized rolling stock, that travels upward of 125mph. It is hypothesized that the feasibility in high speed rail is high due to the current functioning transportation systems in Florida.

Due to the increase in demand on freight transportation it becomes necessary to avoid delays to ensure that the goods reach its destination on time. The main factors causing disturbances in the traffic on the mainline is the breakdown of vehicles mainly due to damaged wheels. The damaged wheels are identified through the wheel-rail impact force measurements provided by the wheel impact load detectors (WILD). This calls for the optimal schedule of maintenance of wheelsets and wagons in general. During the maintenance, the officials manually check for defective wheels and the exchange of wheelsets is performed based on the type of damage. The classification of wheel damages plays a vital role in providing ease of damage identification and insights to deduce a strategy for wheelset exchange. In this study, an attempt to classify the damaged wheelsets is done by analysing the wheel-rail impact force data from the wayside detectors. The data from the detectors are acquired from PredgeAB, a Luleå based startup pioneering in providing decision support on optimal maintenance schedules and predictive maintenance of rail wheels. Through their detection and prediction solutions it was observed that of all the wheels marked as damaged by the detectors 10% were undamaged. The source of the deviation in the impact force readings could help Predge make better estimations in damage detection and prediction. In this study, the sources contributing to the deviation is studied using multi-body simulations in GENSYS. A new method for modelling wheel damage is developed to overcome the shortcomings of the software. The findings of this study can then be used appropriately to make classifications of wheel damages. / På grund av den ökade efterfrågan på godstransporter är det nödvändigt attundvika förseningar för att säkerställa att varorna når sin destination i tid. Deviktigaste faktorerna som orsakar störningar i trafiken på huvudlinjen är stopp ispår av fordon, främst på grund av skadade hjul. De skadade hjulen identifierasmed hjälp av mätningar av slagkraft mellan hjul och spår som tillhandahållsav hjulbelastningsdetektorer (WILD). Detta kräver ett optimerat schema förunderhåll av hjulsatser och vagnar i allmänhet. Under underhållet kontrollerartjänstemännen manuellt för defekta hjul och utbytet av hjulsatser utförs baserat på typen av skada. Klassificeringen av hjulskador spelar en viktig roll närdet gäller att underlätta identifiering av skador och ge insikt för att bedöma enstrategi för hjulbyte. I den här studien görs ett försök att klassificera de skadade hjulsatserna genom att analysera data från slagkraften mellan spår ochhjul från detektorer. Uppgifterna från detektorerna hämtas från PredgeAB, enLuleå-baserad uppstartsbolag som är pionjärer för att ge beslutsstöd om optimala underhållsscheman och prediktivt underhåll av järnvägshjul. Genom sinadetekterings- och prediktiva lösningar observerades att 10% av alla hjul märktasom skadade av detektorerna var oskadade. Källan till avvikelsen i slagkraftavläsningarna kan hjälpa Predge att göra bättre uppskattningar när det gällerupptäckning och förutsägelse av skador. I den här studien studeras de källorsom bidrar till avvikelsen med simuleringar av flera kroppar i GENSYS. En nymetod för modellering av hjulskador har utvecklats för att övervinna programvarans brister. Resultaten av denna studie skulle kunna användas på lämpligtsätt för att göra klassificeringar av hjulskador.

This study focuses on the reliability of railway track in the relation with high loads resulted from wheel damages, where higher (dynamic) vertical wheel loads are expected from trains with damaged wheels. The Swedish Transport Administration (Trafikverket) has monitored and recorded data of rail defects and breaks. This data is important for the risk evaluation and management process, in order to obtain a balance between the maintenance costs and availability and quality of service for the railway transportation. To detect wheel damages in advance, Wheel Impact Loads (WIL) are measured and recorded by Wheel Impact Load Detectors (WILD), which are installed along the Swedish railway network, currently at 29 locations. Additionally, to detect defects and breakages in rails, Ultrasonic Testing (UT) is a common non-destructive testing method used by Trafikverket. In this project, a case study is conducted to examine statistically the frequency of rail defects and rail breaks after trains with high WILs, which exceed 350 kN, continued to operate in a defined area during the winter of 2019/20 at Bodsjön. The case study compares the data of WILD at Bodsjön and UT of the nearby track sections, 211 and 212, over a period of five years, from 2016 to 2020. Rail reliability levels are examined based on the absolute frequencies of rail defects detected by UT and the normalised ones per kilometre of UT-checked track, as well as the severity levels of those rail defects. The severity levels are denoted from the highest to the lowest, as 1a/ 1v/ 1m, 2b and 3i, based on the derailment risks and the priority of maintenance. It is observed that the extremely high WILs in the winter 2019/2020 has coincided with the more severe rail defects found by the following UT in 2020. Furthermore, the dominant rail defect type is found as squats. By studying the frequency of squats and their locations along the defined track sections, it is shown that there is a similar trend in the frequencies of squats and the high WILs. While, the effect of the high WILs’ magnitudes onto the occurrence of squats is undefined. However, the correlation between the frequencies and magnitudes of high WILs and the rail reliability levels could not be determined from this case study due to the limitations in the data collections. The current way of data collections for WILs, wheel damage types and rail defects are discussed for future works. Lastly, the statistics shows that the level of rail reliability of the area defined in the case study is considered as acceptable, considering the recent national levels that have been reported in the annual reports on rail defects. This gives the basis for the possibility of reviewing the permissible power level and proposing a new alert limit value of WIL. Nevertheless, considering the recommendation of The International Union of Railways (UIC) for the international railway sections, the implementation of the increased alert limit of WIL shall be examined carefully, with a future pilot study in railway sections that are not used for international traffic. / Denna studie fokuserar på tillförlitligheten för järnvägsspår i samband med höga laster som orsakas av hjulskador, där högre (dynamiska) vertikala hjullaster förväntas från tåg med skadade hjul. Trafikverket har övervakat och registrerat data om järnvägsfel och avbrott. Dessa uppgifter är viktiga för riskutvärderingen och hanteringsprocessen för att få en balans mellan underhållskostnader och tillgänglighet och kvalitet på järnvägstransportens kvalitet. För att upptäcka hjulskador i förväg, mäts och registreras Wheel Impact Loads (WIL) av Wheel Impact Load Detectors (WILD), som är installerade längs det svenska järnvägsnätet, för närvarande på 29 platser. För att upptäcka defekter och brott i skenor är Ultrasonic Testing (UT) en vanlig icke-destruktiv testmetod som används av Trafikverket.I det här projektet, genomförs en fallstudie för att statistiskt undersöka frekvensen av järnvägsdefekter och rälsavbrott efter tåg med höga WILs, som överstiger 350 kN, fortsatte att köra i ett definierat område under vintern 2019/20 vid Bodsjön. Fallstudien jämför data från WILD vid Bodsjön och UT för de närliggande spåravsnitten, 211 och 212, under en period på fem år, från 2016 till 2020. Järnvägssäkerhetsnivåer undersöks baserat på de absoluta frekvenserna av järnvägsdefekter som upptäcks av UT och de normaliserade per kilometer UT-kontrollerat spår, liksom svårighetsgraden av dessa järnvägsdefekter. Svårighetsgraderna anges från det högsta till det lägsta, som 1a/ 1v/ 1m, 2b och 3i, baserat på urspårningsriskerna och underhållets prioritet.Det observeras att de extremt höga WILs under vintern 2019/2020 har sammanfallit med de allvarligare järnvägsdefekterna som hittades av följande UT år 2020. Vidare återfinns den dominerande järnvägstypstypen som knäböj. Genom att studera frekvensen av knäböj och deras platser längs ett definierat spåravsnitt, visas det att det finns en liknande trend i frekvenserna för knäböj och de höga WILs. Medan effekten av de höga WILs storheter på förekomsten av knäböj är odefinierad. Korrelationen mellan frekvenserna och storheterna för höga WILs och järnvägssäkerhetsnivåerna kunde dock inte fastställas från denna fallstudie på grund av begränsningarna i datasamlingarna. Det nuvarande sättet för datainsamling för WILs, hjulskadetyper och järnvägsdefekter diskuteras för framtida arbeten.Slutligen visar statistiken att nivån på järnvägstillförlitlighet för det område som definieras i fallstudien anses vara acceptabel, med tanke på de senaste nationella nivåerna som har rapporterats i de årliga rapporterna om järnvägsdefekter. Detta ger grunden för möjligheten att granska den tillåtna effektnivån och föreslå ett nytt varningsgränsvärde för WIL. Med tanke på rekommendationen från The International Union of Railways (UIC) för de internationella järnvägssektionerna, ska genomförandet av den ökade varningsgränsen för WIL undersökas noggrant, med en framtida pilotstudie i järnvägssektioner som inte används för internationell trafik.

Tesis por compendio / [ES] El ruido de rodadura de vehículos ferroviarios presenta importantes desafíos en entornos urbanos y suburbanos, siendo precisa una comprensión integral de sus mecanismos subyacentes para una mitigación efectiva. Esta Tesis ofrece una investigación exhaustiva sobre la generación de ruido de rodadura, tanto en vías rectas como curvas, a través del desarrollo de modelos avanzados de alta frecuencia y herramientas de cálculo para una rigurosa predicción de niveles de ruido. El ruido de rodadura surge de la interacción entre las ruedas y los carriles en presencia de imperfecciones en sus superficies de contacto. Los principales componentes ferroviarios que contribuyen a la emisión acústica son las traviesas, los carriles y las ruedas. Las traviesas y los carriles están conectados por medio de las placas de asiento, mientras que las ruedas y los carriles están dinámicamente acoplados a través de su contacto. En consecuencia, cambios en cualquier componente pueden afectar al comportamiento dinámico y acústico del resto, subrayando la necesidad de un modelo integral para abordar eficazmente la radiación por ruido de rodadura. En esta Tesis se exploran y desarrollan diferentes modelos dinámicos de la vía y del eje montado. La vía, que se asume infinita, se describe utilizando la teoría de estructuras periódicas y se caracteriza por sus números y formas de onda. El eje montado se modeliza mediante el Método de Elementos Finitos y se caracteriza por sus frecuencias naturales y modos de vibración. La interacción rueda/carril se describe como una relación linealizada entre el movimiento relativo de ambos componentes y las fuerzas de contacto. Cabe indicar que los modelos explorados en este trabajo están formulados en el dominio de la frecuencia. Asimismo, se realiza un estudio de influencia del diseño de la vía en la radiación por ruido de rodadura, cuantificando los parámetros contribuyentes a la emisión acústica mediante técnicas estadísticas. Los resultados apuntan a que la geometría del carril tiene un impacto limitado en la radiación, mientras que las propiedades viscoelásticas de la vía, en particular la rigidez de la placa de asiento, desempeñan un papel fundamental en la generación de ruido. Es remarcable que, entre los distintos diseños, se han encontrado variaciones de hasta 7,4 dB(A) en la radiación acústica. Durante el desarrollo de esta investigación, se ha prestado atención al modelizado del eje montado. Su rotación se incluye usando coordenadas Eulerianas, lo que resulta un enfoque conveniente ya que el punto de contacto de la rueda con el carril permanece en una posición espacial constante. Dada la simetría axial de su geometría, la respuesta dinámica del eje montado se expande a lo largo de la dirección circunferencial mediante series de Fourier, lo que permite formular el comportamiento dinámico y acústico de este cuerpo tridimensional (3D) en un marco bidimensional (2D), resolviendo analíticamente la coordenada circunferencial. Esta metodología ofrece sin pérdida de generalidad una reducción del tiempo de cálculo computacional, lo que hace que el modelo sea idóneo para su integración en algoritmos de optimización. Por último, se realiza una investigación pionera sobre el ruido de rodadura cuando el vehículo negocia una curva. Si bien la curva está generalmente asociada con el ruido por chirridos, esta Tesis explora y confirma la importancia que también tiene el ruido de rodadura en estas condiciones. Para ello, se modelizan los efectos inerciales y giroscópicos que sufre un eje montado al describir una trayectoria curva. Además, diferentes fenómenos complejos que ocurren en el contacto rueda/carril, como por ejemplo el movimiento relativo entre estos elementos, se incorporan en el modelo de interacción. Los resultados indican que la posición del contacto rueda/carril sirve como un buen indicador del impacto que la negociación de una curva tiene en el ruido de rodadura. / [CA] El soroll de rodament de vehicles ferroviaris presenta importants reptes en entorns urbans i suburbans, requerint una comprensió integral dels seus mecanismes subjacents per a una mitigació efectiva. Aquesta Tesi ofereix una investigació exhaustiva sobre la generació de soroll de rodament, tant en vies rectes com corbes, mitjançant el desenvolupament de models avançats d'alta freqüència i eines de càlcul per a la rigorosa predicció dels nivells de soroll radiat. El soroll de rodament sorgeix de la interacció entre les rodes i els carrils en presència d'imperfeccions en les seues superfícies de contacte. Els principals components ferroviaris que contribueixen a l'emissió acústica són les travesses, els carrils i les rodes. Les travesses i els carrils estan connectats a través de les plaques d'assentament, mentre que les rodes i els carrils estan acoblats mitjançant la seua interacció. En conseqüència, canvis en qualsevol component poden afectar al comportament dinàmic i acústic de la resta, subratllant la necessitat d'un model integral. En aquesta Tesi s'exploren i desenvolupen diversos models dinàmics de la via i de l'eix muntat. La via, que es considera infinita, es descriu utilitzant la teoria d'estructures periòdiques i es caracteritza pels seus números i formes d'ona. L'eix muntat es modelitza mitjançant el Mètode d'Elements Finits i es caracteritza per les seues freqüències naturals i modes de vibració. La interacció entre l'eix muntat i la via es descriu com una relació linealitzada entre el moviment relatiu d'ambdós components i les forces de contacte. Cal assenyalar que els models explorats en aquest treball estan formulats en el domini de la freqüència. Així mateix, es realitza un estudi d'influència del disseny de la via en la radiació, quantificant els paràmetres contribuents a l'emissió acústica mitjançant tècniques estadístiques. Els resultats apunten que la geometria del carril té un impacte limitat en la radiació sonora, mentre que les propietats viscoelàstiques de la via, en particular la rigidesa de la placa d'assentament, tenen un paper fonamental en la generació de soroll. És destacable que, entre els diferents dissenys, s'han trobat variacions de fins a 7,4 dB(A) en la radiació per soroll de rodament. Durant el desenvolupament d'aquesta investigació, s'ha prestat atenció al modelatge de l'eix muntat. La seua rotació s'inclou en la formulació utilitzant coordenades Eulerianes, la qual cosa resulta un enfocament convenient ja que el punt de contacte de la roda amb el carril roman en una posició constant. Donada la simetria axial de la seua geometria, la resposta dinàmica de l'eix muntat s'amplia al llarg de la direcció circumferencial mitjançant sèries de Fourier, permetent formular el comportament dinàmic i acústic d'aquest cos tridimensional (3D) en un marc bidimensional (2D), i resolent la coordenada circumferencial analíticament. Aquesta metodologia ofereix sense pèrdua de generalitat una reducció del temps de càlcul computacional, la qual cosa fa que el model siga idoni per a la seua integració en algoritmes d'optimització. Finalment, es realitza una investigació pionera sobre el soroll de rodament quan el vehicle negocia una corba. Si bé la corba està generalment associada amb el soroll per grinyols, aquesta Tesi explora i confirma la importància que també té el soroll de rodament en aquestes condicions. Per a això, es modelitzen els efectes inercials i giroscòpics que pateix un eix muntat al descriure una trajectòria corba. A més, diferents fenòmens complexes que ocorren en el contacte roda/carril, com el moviment relatiu entre aquests elements, s'incorporen en el model d'interacció. Els resultats indiquen que la posició del contacte roda/carril serveix com un bon indicador de l'impacte que la negociació d'una corba té en el soroll de rodament. / [EN] Rolling noise emission in railway systems presents significant challenges in urban and suburban environments, requiring a comprehensive understanding of its underlying mechanisms for effective mitigation. This Thesis offers a thorough investigation into rolling noise generation, considering both tangent and curved tracks, through the development of advanced high-frequency models and calculation tools to predict noise levels accurately. Rolling noise arises from the interaction between railway wheels and tracks in the presence of roughness on their contact surfaces. The principal components contributing to the acoustic emission are the sleepers, rails, and wheels. Sleepers and rails are interconnected through rail pads, while wheels and rails are dynamically coupled due to their contact. Consequently, changes in any component might impact the dynamic and acoustic behaviour of all of them, outlining the necessity of a comprehensive model to address rolling noise radiation effectively. Various models for the track and wheelset are explored and developed in this Thesis. The track, assumed to be infinite, is described using periodic structure theory and it is characterised by its wavenumbers and waveshapes. The wheelset is modelled through the Finite Element Method (FEM) and it is characterised by its natural frequencies and vibration modes. The wheelset and track interaction is described as a linearised relationship between the relative motion of both components and the contact forces. The models examined in this work are formulated in the frequency domain. Identified track properties influencing rolling noise radiation are quantified using statistical techniques. While the rail geometry is found to have a limited impact on the total radiation, the viscoelastic properties of the track, particularly the rail pad stiffness, play a crucial role in noise generation. Variations up to 7.4 dB(A) were observed for different track designs. Special attention is devoted to the wheelset modelling in this Thesis. Its rotation is considered using Eulerian coordinates, a convenient approach as the wheel contact point with the rail remains at a constant spatial position. Given the axial symmetry of its geometry, the wheelset dynamic response is expanded around the circumferential direction using Fourier series, which yields a two-dimensional (2D) formulation of the dynamic and acoustic behaviour of this three-dimensional (3D) system, with the circumferential coordinate being solved analytically. This methodology, denoted as axisymmetric approach, offers a significant reduction in the associated computational calculation time while preserving accuracy, making the model well suited for its integration into optimisation algorithms. Lastly, a novel investigation into rolling noise when the vehicle negotiates a curve is conducted. While curved tracks are generally associated with squeal noise, this Thesis offers valuable insights into the importance of rolling noise as well. To achieve this, the inertial and gyroscopic effects associated with a wheelset running on a curve are modelled. Complex phenomena occurring at the wheel/rail contact, such as the relative motion between these two elements, are incorporated into the interaction model. The results indicate that the wheel/rail contact position serves as a reliable indicator of the impact of a curve on the rolling noise. / This Thesis has been supported by Ministerio de Ciencia, Innovación y Universidades in the framework of the FPU grant program. Grants FPU18/03999, EST21/00213, and EST22/00353 as well as projects TRA2017-84701-R, PID2020-112886RA-I00, and PID2023-148483OB-I00 funded by MCIN/AEI/10.13039/501100011033, “ESF Investing in your future”, and “ERDF A way of making Europe” are acknowledged. The author also expresses his gratitude for the support provided by Programa PROMETEO/2021/046 of Generalitat Valenciana. / Andrés Ruiz, VT. (2024). Comprehensive dynamic models of railway wheelsets and tracks for the prediction of rolling noise [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/206074 / Compendio

Rail transport refers to the transportation of various commodities, goods and services traded as cargo and freight within South Africa and out of South Africa for export to the other Southern African communities (SADC region), the rest of Africa and other continents of the world. It also refers to the imports into South Africa from the regions mentioned. Competitiveness relates to a country or company’s available resources and supporting policies and regulations in place which allow them to compete and do business locally, internationally and globally while improving the country’s economy and the company’s profitability. There are different criteria that can be used to determine the level of competitiveness, depending on each company or country’s capabilities. In the past years, the progress and development of the South African rail industry has been neglected and this has resulted in the rail transportation not being used. Railway line maintenance has become a challenge and service delivery is below customer expectations. Road transport has better availability and reliability, which has led companies to prefer road transport for freight. The main objective of this study is to reach a detailed understanding of the views of freight rail transport consumers and the impact of rail transport on the economic competitiveness of South Africa. Another important objective is to present the study in a format that is easily understandable. The approach adopted for this study is quantitative and uses a survey research questionnaire which was distributed to freight rail transport customers and providers. The data collected from the questionnaire was submitted to a statistical consultant service at North-West University. The statistical consultant analysed the data using the SPSS statistics computer programme to arrive at the results presented in this study. The overall findings from this study are that companies that use roads to transport freight do so because of the unavailability and unreliability of the freight rail transport provider Transnet Freight Rail and that these companies opt for road transport because they use a ‘just in time’ (JIT) system whereby a small quantity of stock is transported continuously which Transnet Freight Rail (TFR) does not accommodate. These factors have resulted in TFR’s poor service delivery. Therefore, a market demand strategy has been initiated by TFR to improve the performance of the company. It is important to note here that freight rail transport should concentrate on improving service delivery and not only on increasing capacity. The research participants indicated that the TFR objective to move freight back to rail could be accomplished. This will lessen the burden and damage to South African roads and reduce traffic congestion and accidents caused by trucks on the roads. It will also increase employment opportunities and the country’s economic competitiveness while reducing transport costs. All these aspects will make a significant impact on the economy of the country. / MBA, North-West University, Potchefstroom Campus, 2015

Rail transport refers to the transportation of various commodities, goods and services traded as cargo and freight within South Africa and out of South Africa for export to the other Southern African communities (SADC region), the rest of Africa and other continents of the world. It also refers to the imports into South Africa from the regions mentioned. Competitiveness relates to a country or company’s available resources and supporting policies and regulations in place which allow them to compete and do business locally, internationally and globally while improving the country’s economy and the company’s profitability. There are different criteria that can be used to determine the level of competitiveness, depending on each company or country’s capabilities. In the past years, the progress and development of the South African rail industry has been neglected and this has resulted in the rail transportation not being used. Railway line maintenance has become a challenge and service delivery is below customer expectations. Road transport has better availability and reliability, which has led companies to prefer road transport for freight. The main objective of this study is to reach a detailed understanding of the views of freight rail transport consumers and the impact of rail transport on the economic competitiveness of South Africa. Another important objective is to present the study in a format that is easily understandable. The approach adopted for this study is quantitative and uses a survey research questionnaire which was distributed to freight rail transport customers and providers. The data collected from the questionnaire was submitted to a statistical consultant service at North-West University. The statistical consultant analysed the data using the SPSS statistics computer programme to arrive at the results presented in this study. The overall findings from this study are that companies that use roads to transport freight do so because of the unavailability and unreliability of the freight rail transport provider Transnet Freight Rail and that these companies opt for road transport because they use a ‘just in time’ (JIT) system whereby a small quantity of stock is transported continuously which Transnet Freight Rail (TFR) does not accommodate. These factors have resulted in TFR’s poor service delivery. Therefore, a market demand strategy has been initiated by TFR to improve the performance of the company. It is important to note here that freight rail transport should concentrate on improving service delivery and not only on increasing capacity. The research participants indicated that the TFR objective to move freight back to rail could be accomplished. This will lessen the burden and damage to South African roads and reduce traffic congestion and accidents caused by trucks on the roads. It will also increase employment opportunities and the country’s economic competitiveness while reducing transport costs. All these aspects will make a significant impact on the economy of the country. / MBA, North-West University, Potchefstroom Campus, 2015

Trade liberalization and resultantly globalization has led to the relative free flow of goods, services, capital and people. The transport system in South Africa must be highly reliable and rapid to contribute to economic development. The focus of this research study is on the Port/Rail Interface in the Port of Durban which critically assesses the transfer of goods particularly from rail transport to and from vessels within the port precinct. Some of the major constraints identified in the study related to poor infrastructure, operations and levels of services; lack of maintenance, availability of rolling stock, locomotives and cargo stacking space. Transnet's role is pivotal in providing efficient port and rail operations and is currently upgrading infrastructure, operations and capacity of the port and rail services. One of the main objectives of the study is to present recommendations to Transnet management that arise out of the shortcomings identified during the course of the research study. / Transport Economics / M. Comm.

Thesis (MScEng (Mechanical and Mechatronic Engineering))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: The vibrations and noise “pollution” that rail vehicles produce have become of particular concern in recent years. More pressure is being placed on operators of trains and trams (especially those operating in urban environments) to reduce their impact on neighbouring infrastructure. This project investigated the infrastructure available for vibration and noise mitigation and generated material models for some of the materials used in these types of rail infrastructure. The most common type of rail infrastructure used in South Africa is ballasted sleepers. Rail pads are sometimes used to reduce the transmitted vibration of these sleepers; this study focused on the materials used in the manufacture of these pads. Since most of these materials can be described as resilient/viscoelastic, the study of literature regarding these materials is essential within the scope of this project. Models found in literature were adapted by the addition of a non-linear stiffness element to account for the material behaviour at higher preloads. Three commercially available materials were tested and optimisation algorithms applied to determine their material coefficients (damping and stiffness), focusing on the preload and frequency dependency of these coefficients. / AFRIKAANSE OPSOMMING: Die vibrasie en geraas “besoedeling” wat spoor voertuie genereer het in die in die afgelope paar jare van kritieke belang geword. Meer druk word op operateurs van treine en trems geplaas (veral die operateurs met operasies in stedelike gebiede) om hulle impak op aangrensende infrastruktuur te verminder. Hierdie projek is dus daarop gemik om te bepaal watter infrastuktuur beskikbaar is vir die vermindering van vibrasie en geraas asook die ontwikkeling van materiaal modellle vir sommige van die materiale wat gebruik word in hierdie tipes van spoor infrastruktuur. Die mees algemene spoor infrastruktuur wat gebruik word in Suid-Afrika is dwarslêers met ballas. Spoor blokke word soms gebruik om die oordrag van vibrasies te verminder vir hierdie dwarslêers en daarom het hierdie studie fokus geplaas op die materiale wat gebruik word in die vervaardiging van hierdie blokke. Aangesien die meeste van hierdie materiale beskryf kan word as veerkragtig/visco, is 'n literatuurstudie oor hierdie materiale noodsaaklik binne die bestek van hierdie projek. Modelle wat gevind is in die literatuur is aangepas deur 'n nie-lineêre styfheids element by te voeg wat voorsiening maak vir die materiale se gedrag by hoër voorspannings. Drie algemene kommersieël beskikbare materiale is getoets en optimeringsprossesse is toegepas om hulle materiaal koëffisiënte (demping en styfheid) te bepaal met die klem geplaas op die voorspanning en frekwensie afhanklikheid van hierdie koëffisiënte.

published_or_final_version / abstract / Transport Policy and Planning / Master / Master of Arts in Transport Policy and Planning