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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
201

Modelling and analysis of rail grinding and lubrication strategies for controlling rolling contact fatigue (RCF) and rail wear.

Reddy, Venkatarami January 2004 (has links)
Rails play a significant role in transport of goods and passengers. In Australia railway transport industry contributes 1.6% of GDP with goods and services worth $AUD 8 billion each year which includes $ AUD 0.5 billion per year in exports (Australasian Railway Authority Inc, 2002). Rail track maintenance plays an important role in reliability and safety. The Office for Research and Experiments (ORE) of the Union International des Chemins de Fer (UIC) has noted that maintenance costs vary directly (60-65 per cent) with change in train speed and axle load. It was also found that the increase in these costs with increased speed and axle load was greater when the quality of the track was lower (ORR, 1999). Failures during operation are costly to rail players due to loss of service, property and loss of lives. Maintenance and servicing keep rail tracks in operating, reliable and safe condition. Therefore, technical and economical analysis is needed by rail players to reduce maintenance cost and improve reliability and safety of rail networks. Over the past few years, there have been major advances in terms of increased speed, axle loads, longer trains, along with increased traffic density in corridors. This has led to increased risks in rail operation due to rolling contact fatigue (RCF) and rail wear. The infrastructure providers have less incentive to maintain a given infrastructure standard if its access charges are rigid and rolling stock standard is not achieved. It has been estimated that between 40 to 50 per cent of wagon maintenance costs and 25 per cent of locomotive maintenance costs are related to wheel maintenance (Railway Gazette International, 2003). The economic analysis of Malmbanan indicates that about 50% of the total cost for maintenance and renewal were related to traffic on rails and 50% not related to traffic, such as signaling, electricity and snow-clearance. The results from the analysis have made it possible for the mining company LKAB to start up the 30 Tonnes traffic with new wagons and locomotives on the Malmbanan line in year 2001 (Åhrén et al 2003). The rail infrastructure providers have challenges to maintain infrastructure due to government control on access charges and limited control on rail operations. The aim of the research is to: · Develop a maintenance cost model for optimal rail grinding for various operating conditions; and · Develop integrated rail grinding and lubrication strategies for optimal maintenance decisions. In this research real life data has been collected, new models have been developed and analysed for managerial decisions. Simulation approach is used to look into the impact on various costs such as rail grinding, operating risk, down time, inspection, replacement, and lubrication. The results of the models for costs and the effect of rail grinding and lubrication strategies are provided in this thesis. In this research rail track degradation, rail failures and various factors that influence rail degradation are analysed. An integrated approach for modelling rail track degradation, rail wear, rail grinding and lubrication is developed. Simulation model and cost models for rail grinding are developed and analysed. It has been found through this research that rail grinding at 12 MGT interval is economic decision for enhancing rail life. It was also found that lubrication is most effective compared to stop/start and no lubrication strategies in steep curves. Rail grinding strategies developed in this research have been considered by Swedish National Rail for analysing the effectiveness of their existing policies on grinding intervals. Optimal grinding and lubrication decisions have huge potential for savings in maintenance costs, improving reliability and safety and enhancing rail life.
202

Modeling of water and lubricant sprays in hot metal working

Liu, Chun, January 2007 (has links)
Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 244-259).
203

The numerical solution of the elastohydrodynamically lubricated line- and point contact problem, using multigrid techniques proefschrift /

Lubrecht, A. A. January 1900 (has links)
Thesis (Ph. D.)--Universiteit Twente, 1987.
204

Measurement and modeling of fluid pressures in chemical mechanical polishing

Ng, Sum Huan. January 2005 (has links) (PDF)
Thesis (Ph. D.)--Mechanical Engineering, Georgia Institute of Technology, 2005. / Steven Danyluk, Committee Chair ; Richard Salant, Committee Member ; Jeffrey Streator, Committee Member ; Michael Sacks, Committee Member ; Dennis Hess, Committee Member ; Leonard Borucki, Committee Member. Includes bibliographical references.
205

Electrochemical sensors for the detection of tricresyl phosphate and determination of acid content in engine oils

Epur, Rigved, Simonian, Aleksandr L., January 2009 (has links)
Thesis--Auburn University, 2009. / Abstract. Vita. Includes bibliographical references (p. 105-116).
206

Structure and low-temperature tribology of lubricious nanocrystalline ZnO/Al₂O₃ nanolaminates and ZrO₂ monofilms grown by atomic layer deposition

Romanes, Maia Castillo. Scharf, Thomas W., January 2008 (has links)
Thesis (Ph. D.)--University of North Texas, Dec., 2008. / Title from title page display. Includes bibliographical references.
207

The numerical solution of the elastohydrodynamically lubricated line- and point contact problem, using multigrid techniques proefschrift /

Lubrecht, A. A. January 1900 (has links)
Thesis (Ph. D.)--Universiteit Twente, 1987.
208

Coefficients of static friction for lubricated steel surfaces

Sarin, Lalit Kumar. January 1965 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1965. / eContent provider-neutral record in process. Description based on print version record. Bibliography: l. 64-66.
209

Predictive modeling of near dry machining mechanical performance and environmental impact /

Li, Kuan-Ming. January 2006 (has links)
Thesis (Ph. D.)--Mechanical Engineering, Georgia Institute of Technology, 2007. / Dr. Liang, Steven Y., Committee Chair ; Dr. Melkote, Shreyes N., Committee Member ; Dr. Vengazhiyil, Roshan Joseph, Committee Member ; Dr. Zhou, Chen, Committee Member ; Dr. Zhou, Min, Committee Member.
210

Development of a generalized mechanical efficiency prediction methodology for gear pairs

Xu, Hai, January 2005 (has links)
Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Includes bibliographical references (p. 227-233).

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