Wear of railroad rolling stock and rails costs millions of dollars annually in all rail systems throughout the world. The rail industry has attempted to address flange wear using rail curve lubricants and presently use a variety of lubricants and lubricant applicators. The choice of lubricant and applicator is currently based on considerations that do not address the wear problem directly. This research quantified rail curve lubricant performance through laboratory simulation. The effects of lubricants in the wheel/rail contact were investigated. Rail curve lubricant performance was measured with a laboratory rail/wheel simulator for the purpose of optimising the choice of lubricant. New methods for measurement of rail curve lubricant performance have been presented. These performance measurements are total absorbed energy, the energy absorbed in the lubricant film instead of being utilised for wear processes; total distance slid, the sliding distance or accumulated strain achieved prior to development of a set tractive force limit; half life of lubricant, the time taken for a lubricant to lose half of its sliding performance; and apparent viscosity, a measure of the lubricity presented with respect to accumulated strain. The rail/wheel simulator used in this research consists of two dissimilar wheels (disks) rotating in contact with one another simulating a conformal gauge corner contact. The first wheel, a simulated rail, is driven by an electric motor which then drives the second wheel, a simulated railroad wheel, through the contact. Hydraulic braking on the railroad wheel is used to simulate the rolling/sliding conditions. The variables of the simulated contact that are controlled with this equipment are normal force, input wheel speed, slip ratio between samples, sample geometries and material properties, and lubricant types. Rail curve lubricants were laboratory tested to define their properties using the ASTM and other appropriate standards. The performance differences measured using ASTM standards based tests were susceptible to repeatability problems and did not represent the contact as accurately as the rail/wheel simulator. This laboratory simulator was used to gather data in lubricated and unlubricated conditions for the purpose of providing lubricant performance measurements. These measurements were presented and the tested lubricants were ranked conclusively using three industrially relevant performance criteria. Total sliding distance and total absorbed energy measurements of the rail curve lubricants displayed clear differences in lubricant performance for both of these criteria. Total sliding distance is equivalent to the number of axles in the field situation, while total absorbed energy is the energy unavailable for wear processes of rails and wheels. Lubricants designed using these measurements will increase lubricant performance with respect to these performance criteria which in turn will reduce wear to both rails and wheels. Measurement of the apparent viscosity of rail curve lubricants, using the rail/wheel simulator, displayed changes in rheological characteristics with respect to accumulated strain. Apparent viscosity is a measure of the shear stress transmitted from the wheels to the rails. Designing a rail curve lubricant after analysing measurements taken from the rail/wheel simulator will assist in identifying lubricant properties to reduce the wear producing shear stresses generated in a rail wheel contact. Decay of lubricant performance was measured for three different rail curve lubricants under simulated conditions. The research found appreciable and quantifiable differences between lubricants. Industrial application of the findings will improve positioning of lubrication systems, improve choice of lubricants and predict effective lubrication distance from the lubricant application point. Using the new methods of lubricant performance measurement developed in this thesis, the objective of this research, to quantify rail curve lubricant performance through laboratory simulation, has been achieved.

Defected wheel are one the major reasons endangered state of railroad vehicles safety statue, due to vehicle derailment and worsen the quality of freight and passenger transportation. Therefore, timely defect detection for monitoring and detecting the state of defects is highly critical. This thesis presents a passive non-contact acoustic structural health monitoring approach using ultrasonic acoustic emissions (UAE) to detect certain defects on different structures, as well as, classifying the type of the defect on them. The acoustic emission signals used in this study are in the ultrasonic range (18-120 kHz), which is significantly higher than the majority of the research in this area thus far. For the proposed method, an impulse excitation, such as a hammer strike, is applied to the structure. In addition, ultrasound techniques have higher sensitivity to both surface and subsurface defects, which make the defect detection more accurate. Three structures considered for this study are: 1) a longitudinal beam, 2) a lifting weight, 3) an actual rail-wheel. A longitudinal beam was used at the first step for a better understanding of physics of the ultrasound propagation from the defect, as well, develop a method for extracting the signature response of the defect. Besides, the inherent directionality of the ultrasound microphone increases the signal to noise ratio (SNR) and could be useful in the noisy areas. Next, by considering the ultimate goal of the project, lifting weight was chosen, due to its similarity to the ultimate goal of this project that is a rail-wheel. A detection method and metric were developed by using the lifting weight and two type of synthetic defects were classified on this structure. Also, by using same extracted features, the same types of defects were detected and classified on an actual rail-wheel. / Master of Science

The main goal of this research is to develop new and innovative designs for insulated rail joints for improved life cycle and higher cost effectiveness. The research focuses on using electrically insulating materials that replace the epoxy used in current bonded insulated joints. Insulated joints (commonly known as "IJ") are widely used on railways to electrically insulate rail segments from each other, while mechanically connecting them together. The electrical insulation is necessary for accommodating track signals. The mechanical strength is needed to ensure the rail and IJs are able to withstand the vertical, longitudinal, and lateral forces that commonly occur on track. Insulating materials that can replace the epoxy used in bonded insulated joints are researched. The electrical insulation properties and mechanical strength of different materials are examined to determine the suitability of different materials for use in insulated joint. The most promising materials for use are determined to be fiber reinforced polymers and ceramics. Insulated joint designs are developed to accentuate the strengths of these two materials. The Insulating Metal Composite (IMC) insulated joint design that uses ceramics is determined to be the most promising of the new designs and is pursued through prototype fabrication. This particular joint design is analyzed structurally using both closed form analysis and FEA analysis using the software package ABAQUS. Electrical analysis using PSPICE is carried out on the joint. Prototypes of several design iterations of the insulating metal composites are built and tested. A proof of concept static bending test of the insulating metal composites used to build the IMC insulated joint is performed using a Tinius Olsen compressive tester. A rolling-wheel load test is performed on a prototype IMC component installed in rail. Finally, a prototype of a complete IMC insulated joint is fabricated and installed on the FAST test track at TTCI facility in Pueblo, Colorado for field evaluation. Electrical testing using a megohmmeter is performed on a complete prototype joint. Structural analysis shows that the components used to construct the IMC insulated joint can withstand the vertical and longitudinal loads applied to them. Electrical analysis shows that the joint can provide adequate electrical insulation and provides the required dielectric strength in the AREMA Manual for Railway Engineering. The proof of concept test shows that an IMC component can withstand 100 kips of static load without damage. The rolling-wheel load test shows that the ceramic in the IMC components can withstand a large shock load and that the rail used in the IMC insulated joints can survive repeated and shock loads. The testing of the prototype joint on the FAST track, which is ongoing at this time has shown that the new joint concept is fully capable of providing adequate electrical insulation and mechanical strength throughout the expected life of IJs. / Master of Science

The adhesion in the wheel-rail contact can be effectively controlled by using the friction modifier. Adhesion control can reduce excessive wear of the contact bodies or noise. The essence of this diploma thesis is to determine the optimal amount of friction modifier in wheel-rail contact depending on the climatic and operating conditions. For experimental study of the behavior of the friction modifier, the twin-disc device is used. Twin-disc simulates and controls the most important operating parameters such as speed, slip, attack angle or contact pressure. On the basis of these findings, the off-board top-of-rail lubricator system was designed. This system controls the amount of friction modifier according to current climatic and operating conditions.

This Master´s thesis deals with the determination of the propagation directions of primary crack in the rail vehicles wheel under operating conditions. The aim of this work is the stress-strain analysis with using fracture mechanics to examinate behaviour of primary cracks for different operating conditions, i.e. rotation, rotation with contact and assessment of refracted cracks with applied rotation and contact.