Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 7 of 7 for “"track stability"”.
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NUCARS Modeling of a Freight Locomotive with Steerable Trucks
… used to conduct a study of the impact on tangent track stability and curving performance of varying suspension parameters. It is found that the presence of damping in the system improves hunting stability, while increasing wheel conicity is harmful to stability and varying the flexicoiling …
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Discrete Element Modeling of Railway Ballast for Studying Railroad Tamping Operation
… for achieving sustainable improvements in the track stability after tamping. The simulation model is developed using a commercially available DEM software called PFC3D (Particle Flow Code 3D). A detailed explanation is provided about how to set up the DEM model of railway ballast considering …
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Machine learning techniques for identifying railroad ballast degradation
… to the subgrade layer, provides lateral track stability and facilitates the drainage of water. Repeated traffic loading and environmental factors cause particle breakage, abrasion and polishing, which eventually degrade the ballast and result in fouling conditions. Traditional ballast …
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Discrete Element Modeling of Railway Ballast for Studying Railroad Tamping Operation
… model is constructed with high degree of adjustability to allow control of all process parameters for achieving realistic output. The analysis shows that DEM is a highly valuable tool for studying railroad tamping operation. It has the capability to provide crucial and unprecedented insights …
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Field Evaluation of Doppler LIDAR Sensors for Early Assessment of Track Instability
… the use of Doppler Lidar sensors for assessing track weakening that would indicate early stages of track instability. Such track weakening could lead to gage widening or track buckling due to rail thermal expansion. A series of tests are performed at the Transportation Technology Center's High …
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Integrated computational and experimental framework for the assessment of railroad ballast life-cycle behavior
… gradation, is an essential layer in the railroad track substructure. Functions of ballast include facilitating load distribution and drainage, maintaining track geometry and track stability, and providing track resilience and noise absorption. Throughout its service life, ballast goes through …
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Computational-Experimental Process Development for Laser Powder Bed Fusion Additive Manufacturing
… parameters. A methodology for performing melt track experiments using high-precision metal templates as well as a machine learning-based automated image analysis tool is presented and applied to melt track scaling studies. Based on single track parameter studies with layer thicknesses and laser …