Browsing by Author "Palese, Joseph W."
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Item A data-driven approach to rail wear modeling(University of Delaware, 2019) Palese, Joseph W.Steel rail is one of the railways most vital track assets and is critical for safe and efficient operations. Rail fails due to loss of section (through various wear mechanisms) as well as fatigue. Maintaining the structural integrity of the rail is paramount and railways have implemented sophisticated inspection vehicles to monitor track components, including measuring the transverse profile of the rail. The resulting data is extensive and proliferate for many railways. Traditionally, railways have used simple threshold analyses of this extensive data to make maintenance decisions. ☐ Rail wear has been the subject of extensive research for the past century. Past research has focused on laboratory testing (along with field-testing) to evaluate metallurgical performance, benefits of lubrication, and basic wear relationships as a function of contact (creep, sliding, etc.). This has resulted in wear coefficients that have been employed in a linear relationship with load. The results have been deterministic/mechanistic and empirical models that provide valuable information with respect to one or more factors that affect wear. The past work has included several simulation modeling approaches, with only limited work performed with respect to modeling rail wear for field conditions. This is due to the fact that many factors affect rail wear in track, and many of these are not, or cannot, be measured. Thus, modeling attempts have resulted in only modest levels of accuracy and practical implementation. ☐ The research conducted herein focused on a stochastic approach to rail wear modeling, using only the data that was readily available. In this manner a probabilistic forecast of rail wear was developed resulting in a range of outputs that are conditionally dependent upon the known inputs. Specifically, Auto Regressive Integrated Moving Average (ARIMA) and Mixture Density Networks (MDNs) were used with a Laplace distribution to understand rail wear relationships, and predict rail wear rates to forecast rail wear. In addition, a stochastic classification scheme was developed, taking advantage of the Laplace cumulative probability function, to assess the wear performance of a rail segment, given the inputs and historic wear relationships for the given dataset. ☐ An extensive Exploratory Data Analysis (EDA) was performed, resulting in a preprocessing phase of the data to determine wear rate, which was then subjected to a secondary EDA. The stochastic methodologies developed and enhanced are fully explained, along with the framework that was developed to bundle the methodologies into a comprehensive model for rail wear analysis. ☐ An application of the model was performed for the dataset provided, 277 miles of railway with multiple inspections over 6 years (more than 2 million rail profiles and corresponding wear measurements), and the results discussed in detail, particularly from a practical implementation perspective. The research resulted in a framework that allows for structural health monitoring of the rail component of the track structure, with regard to rail wear.Item Hazard assessment framework for statistical analysis of cut slopes using track inspection videos and geospatial information(Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards, 2023-06-12) Palese, Michael; Pei, Te; Qiu, Tong; Zarembski, Allan M.; Shen, Chaopeng; Palese, Joseph W.Transportation corridors constructed using through- and side-cuts are susceptible to hazardous slope failures, potentially causing infrastructure damage, operational suspensions and loss of life. To monitor the stability of known geohazards at the local scale, geotechnical investigation of each slope is typically performed to calculate a factor of safety. In many corridors, however, this method is labour-intensive due to the quantity of geohazards and statistical methods are instead used to identify hazardous sections. This paper introduces a new slope failure hazard assessment technique, utilising susceptibility mapping of geospatial information and computer vision-based analysis of right-of-way videos recorded by railroad track inspection vehicles, applied to a section of railroad track near Harrisburg, Pennsylvania. Combining these results, an enhanced relative hazard assessment algorithm was formulated. Using the developed framework, geohazards of primary concern were determined which should be prioritised for future geotechnical investigation and remediation efforts.Item Intelligent System for Real-Time Prediction of Railway Response to the Interaction with Track Geometry(American Society of Mechanical Engineers, 2000-04) Bonaventura, Clifford S.; Palese, Joseph W.; Zarembski, Allan M.Safe interaction of railway vehicles to track and its geometry is of paramount importance to the railroad industry. Railroads currently utilize track geometry cars to measure the geometry for comparison to safety limits. However, these limits are set for individual measures of track geometry such as gage, surface (or profile), alignment, cross-level, etc. and have been defined based on nominal vehicle characteristics. The track and vehicle do not act independently, however, and so it is more appropriate to analyze the vehicle/track interaction. Prediction of the vehicle dynamic response to existing track geometry can be used to locate potentially unsafe locations in track, based on a range of vehicle configurations and operating speeds. While this is currently done in an offline mode, it would be advantageous to achieve this on a track geometry car in real-time. A limited real-time dynamic simulation system was developed for just this purpose. The model was initially based on the Track Analyzer method developed by Volpe National Transportation Systems Center, but was significantly enhanced in order to provide accurate predictions over a wider variety of vehicle behavior, and in response to a wider variety of track geometry conditions. Responses predicted by the model, including the vehicle bounce, roll, and pitch, as well as vertical wheel/rail forces, are compared with established limitations on vehicle response in order to identify unsafe locations in track. Inputs to the model include the relevant physical parameters of the vehicle, the range of vehicle travelling speeds to be analyzed, and the dynamic response safety thresholds with which exceptions are located. Finally, the system was validated (by comparison with NUCARS predictions) and tested for its real-time capabilities.Item Limiting High Speed Dynamic Forces on the Track Structure The Amtrak Acela Case(American Railway Engineering Association, 2001-09) Zarembski, Allan M.; Bell, John G.; Palese, Joseph W.As vehicle operating speeds increase, the dynamic wheel/rail impact forces applied to the track structure likewise increase. This results in the potential for increased track degradation, component failure, and corresponding increased track maintenance costs. In the case of Amtrak's new generation high speed trains, a specific requirement for the design of the new equipment was to avoid any increase in dynamic forces applied to the track in spite of the increase in operating speed from 125 to 150 mph. In order to achieve this, and maintain (or possibly decrease) the dynamic wheel/rail forces, key equipment design characteristics, to include vehicle unsprung mass and suspension characteristics, were evaluated from this point of view. This report describes the process of examining alternative high-speed equipment designs from the perspective of the track structure and the level of dynamic force applied to the track. This includes the process used to evaluate the dynamic wheel/rail forces generated by both the older 125-mph equipment and the new generation high-speed (150-mph) equipment and the comparison between load levels. This also includes the methodology used to evaluate the potential for track damage (e.g. cracking of the concrete ties on the Northeast Corridor) associated with both the older equipment and the new high speed equipment.