掌桥科研

您现在的位置:首页>外文会议>会议详情

会议信息

会议名称:

ASME joint rail conference

召开年:

2016

召开地:

Columbia, SC

会议文集:

ASME joint rail conference 2016: ASME (American Society of Mechanical Engineers) 2016 joint rail conference (JRC2016), April 12-15 2016, Columbia, South Carolina, USA

主办单位:

American Society of Mechanical Engineers

出版时间:

-
全选 (0)
678条结果 1/20
  • 题名 作者 来源 发表时间 操作
  • CHAIR'S WELCOME MESSAGE

    作者:David Thurston; 会议名称:ASME joint rail conference 2018年

    What a great way to begin the 2018 JRC! Pittsburgh has been a railroad town for over 160 years. These hills have hosted countless suppliers, universities and researchers, and that tradition continues today. There are several unique locations related to rail and transit that should be of interest to you, and we have provided the opportunity to see some of them on the tours sponsored by the conference. This version of the JRC would not be possible without the considerable efforts of the Organizing Committee, without whose countless volunteer hours of setting venues, reviewing papers, and providing the leadership to make this all possible. IEEE, the lead organization for this year's conference, is pleased to partner with our sponsoring organizations including ASME, ASCE, APTA, AREMA, INFORMS, TRB, and the National University Rail Center (NURail) to produce the sole academic conference devote to rail in North America. This year's edition brings over 140 technical papers and presentations covering all aspects of railroad engineering from fourteen countries and five continents.

    关键字:

  • CHAIR'S WELCOME MESSAGE

    David Thurston;

    ASME joint rail conference

    2018年

  • SIMULATING BALLAST BREAKAGE UNDER REPEATED LOADING USING THE DISCRETE ELEMENT METHOD

    作者:Beema Dahal;S M Naziur Mahmud;Debakanta Mishra; 会议名称:ASME joint rail conference 2018年

    The ballast layer in a railroad track helps distribute loads from the superstructure to the formation; a well-designed ballast layer is also meant to prevent excessive vertical, lateral and longitudinal movement of the track under loading. When subjected to repeated loading, the granular ballast particles often undergo breakage leading to significant changes in the shear strength as well as drainage characteristics of the ballast layer. Excessive ballast degradation leads to increased vertical settlements, and is often associated with speed restrictions and increased passenger discomfort. Several researchers in the past have studied the phenomenon of ballast breakage in a laboratory setting. However, due to complexities associated with these large-scale laboratory tests, detailed parametric studies are often not feasible. In such cases, numerical modeling tools such as the Discrete Element Method (DEM) become particularly useful. This paper presents findings from an ongoing research effort at Boise State University aimed at studying the phenomenon of ballast breakage under repeated loading using a commercially available Discrete Element Package (PFC3D®). Ballast particles were simulated as clusters of balls bonded together, and were allowed to undergo breakage when either the maximum tensile stress or the maximum shear stress exceeded the corresponding bond strength value. Different factors studied during the parametric analysis were: (1) load amplitude; (2) loading frequency; (3) number of cycles of loading; (4) bond strength; and (5) particle size distribution. The objective was to identify the relative importance of different factors that govern the permanent deformation behavior of railroad tracks under loading.

    关键字:

  • SIMULATING BALLAST BREAKAGE UNDER REPEATED LOADING USING THE DISCRETE ELEMENT METHOD

    Beema Dahal;S M Naziur Mahmud;Debakanta Mishra;

    ASME joint rail conference

    2018年

  • EFFECT OF GEOGRID INCLUSION ON BALLAST RESILIENT MODULUS: THE CONCEPT OF 'GEOGRID GAIN FACTOR'

    作者:S M Naziur Mahmud;Debakanta Mishra;David O. Potyondy; 会议名称:ASME joint rail conference 2018年

    Geogrid reinforcement of railroad ballast improves its structural response under loading, limits lateral movement of ballast particles, and reduces vertical settlement through effective geogrid-ballast interlocking. This improved performance can be linked to improved shear strength and resilient modulus properties. An ongoing research study at Boise State University is focusing on investigating the effects of different specimen and test parameters on the mechanism of geogrid-ballast interaction. A commercially available Discrete Element Modeling (DEM) program (PFC3D®) is being used for this purpose, and the effect of geogrid inclusion is being quantified through calculation of the "Geogrid Gain Factor", defined as the ratio between resilient-modulus of a geogrid-reinforced ballast specimen and that of an unreinforced specimen. Typical load-unload cycles in triaxial shear strength tests are being simulated, and parametric studies are being conducted to determine the effects of particle-size distribution, geogrid aperture size, and geogrid location on railroad-ballast modulus. This paper presents findings from the research study, and presents inferences concerning implications of the study findings on design and construction of better-performing ballast layers.

    关键字:

  • EFFECT OF GEOGRID INCLUSION ON BALLAST RESILIENT MODULUS: THE CONCEPT OF 'GEOGRID GAIN FACTOR'

    S M Naziur Mahmud;Debakanta Mishra;David O. Potyondy;

    ASME joint rail conference

    2018年

  • EFFECTS OF COVER, COMPRESSIVE STRENGTH, AND WIRE TYPE ON BOND PERFORMANCE IN PRISMATIC PRESTRESSED CONCRETE MEMBERS

    作者:Adrijana Savic;Robert J. Peterman;B. Terry Beck;Jeremiah Clark;Aaron A. Robertson;Chin-Hang (John) Wu; 会议名称:ASME joint rail conference 2018年

    The bond between wire and concrete is crucial for transferring the stresses between the two materials in a prestressed concrete member. Furthermore, bond can be affected by such variables as thickness of concrete cover, type of pre-stressing (typically indented) wire used, compressive (release) strength of the concrete, and concrete mix. This work presents current progress toward the development of a testing procedure to get a clear picture of how all these parameters can ruin the bond and result in splitting. The objective is to develop a qualification test procedure to proof-test new or existing combinations of pre-stressing wire and concrete mix to ensure a reliable result. This is particularly crucial in the concrete railroad crosstie industry, where incompatible conditions can result in cracking and even tie failure. The goal is to develop the capability to readily identify compatible wire/concrete designs "in-plant" before the ties are manufactured, thereby eliminating the likelihood that defectively manufactured ties will lead to in-track tie failures due to splitting. The tests presented here were conducted on pre-tensioned concrete prisms cast in metal frames. Three beams (prismatic members) with different cross sections were cast simultaneously in series. Four pre-stressing wires were symmetrically embedded into each concrete prism, resulting in a common wire spacing of 2.0 inches. The prisms were 59.5in long with square cross sections. The first prism was 3.5x3.5in with cover 0.75in, the second was 3.25x3.25in with cover 0.625in and the third prism in series was 3.0x3.0 in with cover 0.50in. All pre-stressing wires used in these initial tests were of 5.32 mm diameter and were of the same wire type (indent pattern) denoted by "WE", which had a spiral-shaped geometry. This is one of several wire types that are the subject of the current splitting propensity investigation. Others wire types include variations of the classical chevron shape, and the extreme case of smooth wire with no indentions. The wires were initially tensioned to 7000 pounds (31.14 KN) and then gradually de-tensioned after reaching the desired compressive strength. The different compressive (release strength) strength levels tested included 3500 psi (24.13 MPa), 4500psi (31.03 MPa), 6000 psi (41.37 MPa) and 12000psi (82.74MPa). A consistent concrete mix with water-cement ratio 0.38 was used for all castings. Geometrical and mechanical properties of test prisms were representative of actual prestressed concrete crossties used in the railroad industry. Each prism provided a sample of eight different and approximately independent splitting tests of concrete cover (four wire cover tests on each end) for a given release strength. After de-tensioning, all cracks that appeared on the prisms were marked, and photographs of all prism end surfaces were taken to identify the cracking field. During the test procedure longitudinal surface strain profiles, along with live-end and dead-end transfer lengths, were also measured using an automated Laser-Speckle Imaging (LSI) system developed by the authors. Both quantitative and qualitative assessment of cracking behavior is presented as a function of cover and release strength. In addition to the identification of whether cracking took place at each wire end location, measurements of crack length and crack area are also presented for the given WE wire type. The influence of concrete cover and release strength are clearly indicated from these initial tests. The influence of indented wire type (indent geometry) will also be discussed in this paper, along with a presentation of some preliminary test results. This work represents a successful first step in the development of a qualification test for validating a given combination of wire type, concrete cover, and release strength to improve the reliability of concrete railroad crosstie manufacturing.

    关键字:

  • EFFECTS OF COVER, COMPRESSIVE STRENGTH, AND WIRE TYPE ON BOND PERFORMANCE IN PRISMATIC PRESTRESSED CONCRETE MEMBERS

    Adrijana Savic;Robert J. Peterman;B. Terry Beck;Jeremiah Clark;Aaron A. Robertson;Chin-Hang (John) Wu;

    ASME joint rail conference

    2018年

  • ENVIRONMENTAL AND TRACK FACTORS THAT CONTRIBUTE TO ABRASION DAMAGE

    作者:Kyle A. Riding;Spencer Guthrie;Hossein Mosavi;Wyatt Risovi-Hendrickson;Robert J. Peterman;Matthew Brueseke;Koby Daily; 会议名称:ASME joint rail conference 2018年

    Sites with known occurrences of mud pumping or other track concerns were investigated to determine the prevalence of concrete bottom tie abrasion and environmental and track conditions that could contribute to its occurrence. Field investigations showed that it occurs in diverse geographic locations around the U.S. and is a source of continued maintenance concern for railroads. Water appeared to be a significant factor involved in concrete bottom tie abrasion. Ballast fouling, center-binding cracking, rail surface profile variations, and large track movement during loading was seen in locations with concrete bottom tie abrasion. Bumps or track stiffness changes were often found at locations of abrasion damage. Specifically, some locations with known stiff track conditions exhibited significant abrasion damage.

    关键字:

  • ENVIRONMENTAL AND TRACK FACTORS THAT CONTRIBUTE TO ABRASION DAMAGE

    Kyle A. Riding;Spencer Guthrie;Hossein Mosavi;Wyatt Risovi-Hendrickson;Robert J. Peterman;Matthew Brueseke;Koby Daily;

    ASME joint rail conference

    2018年

  • DETERMINING THE REMAINING PRESTRESS FORCE IN A PRESTRESSED CONCRETE RAILROAD TIE THROUGH LOADING IN DIRECT TENSION

    作者:James D. Scott;Aaron A. Robertson;Robert J. Peterman;Kyle A. Riding;B. Terry Beck;Chin-Hang John Wu; 会议名称:ASME joint rail conference 2018年

    Extensive research has been conducted by the research team in recent years to determine the prestressing steel and concrete properties that must be provided to ensure that the transfer length of a prestressed concrete railroad tie is shorter than the distance from the edge of the tie to the rail seat. In addition, a significant of amount of data has been collected that indicates high bonding stresses can produce longitudinal splitting cracks along the reinforcement. In a study of how prestressing steel and concrete properties relate to a ties propensity for longitudinal cracking, existing ties that have performed well in track for over 25 years without issues are being evaluated. One parameter of interest that affects the bonding stress is the amount of prestress force in a railroad tie, which is unknown for the existing ties being evaluated. The current paper focuses on a new method that was developed for determining the remaining prestress force in a tie. In a previous method for determining the prestress force, ties were first loaded in four-point bending to initiate flexural cracking. The crack opening displacement was measured in order to determine the applied load required to reopen the crack. Using this load and the cross-sectional parameters at the location of the crack, the prestress force in the tie can be calculated using static equilibrium. The issue with this method is that as a tie is being loaded and the crack propagates, there is a continuous change in the stiffness of the cross-section. This results in the load versus crack opening displacment curve being overly rounded. This increases the error when determining the load required to reopen the crack, and increases the uncertainty of the calculated prestress force. The new test method eliminates the problems associated with flexural testing by loading the ties longitudinally in tension. In the new proposed experimental method, ties that have been pre-cracked in the center are pulled in tension. Similar to the previous method, the crack opening displacement is measured while the tie is loaded. For the crack to fully open, the applied load must exceed the prestress force holding the crack closed. Prior to the crack opening, the applied load is resisted by the composite section of concrete and prestressing tendons. Once the crack as fully opened, the applied load is resisted by the prestessing tendons only. This creates two distinctly linear portions of the load versus crack opening displacement curve, one prior to the crack opening, and one after. The beginning of the linear portion post-crack opening marks a very clear upper bound for the amount of prestressing force in a tie. This method can estimate the remaining prestress force in a tie with much greater accuracy than the previous method, and eliminates the need of the cross-sectional parameters at the crack location. To verify this method, tests were first conducted on a smaller scale with prismatic beams with a known initial prestressing force. Then the method was applied to a full scale existing tie to determine the remaining prestress force. Results are presented for testing of both the prismatic beams, and the full scale tie.

    关键字:

  • DETERMINING THE REMAINING PRESTRESS FORCE IN A PRESTRESSED CONCRETE RAILROAD TIE THROUGH LOADING IN DIRECT TENSION

    James D. Scott;Aaron A. Robertson;Robert J. Peterman;Kyle A. Riding;B. Terry Beck;Chin-Hang John Wu;

    ASME joint rail conference

    2018年

  • MATERIAL CHARACTERISTICS EVALUATION OF EXISTING PRE-STRESSED CONCRETE RAILROAD TIES AFTER SERVICE PERIOD

    作者:Aref Shafiei Dastgerdi;Kyle Riding;Robert J. Peterman;B. Terry Beck; 会议名称:ASME joint rail conference 2018年

    As an important element in track, pre-stressed concrete railroad ties in the high-speed rail industry must meet the safety and performance specifications of high-speed trains. Systematic destructive and non-destructive evaluation of existing concrete ties can lead to a better understanding of the effect of prestressed concrete tie material design on performance and failure within their service life. It has been evident that environmental and climate conditions also have a significant impact on concrete railroad ties, causing various forms of deterioration such as abrasion and freeze-thaw damage. Understanding of the material characteristics that cause failure in different types of existing concrete railroad ties taken from different places is the main focus of this paper. Observing the current status and damages of railroad ties taken from track might give a correlation between the material characteristic and type of distress and cracking seen. Although it has been seen by previous works that effective factors such as air void system and material composition directly affect the performance of concrete ties such as freeze-thaw, material evaluation of existing ties after service life has not been addressed in previous publications. In this research, the authors have investigated the material characteristic such as aggregate and air-void system of existing pre-stressed concrete railroad ties taken from track. However, compressive and splitting tensile strength and fractured surface of samples cored from the ties were acquired. In order to obtain the strength of concrete materials of existing ties, six samples were cored from six different types of ties taken from tracks across the U.S., according to ASTM C42-16, and tested using ASTM C39 and ASTM C496 methods. However, the concrete air-void system (ASTM C457) was measured on saw-cut samples extracted from the ties to evaluate the influence air content and distribution on mechanical properties of the ties. Regarding the history and service life condition of the ties, it seems that material properties of the ties effectively alter the performance of the ties. Aggregate sources used at each location may have different properties such as texture, angularity, and mineralogy, contributing either propagation or resistance in splitting cracking in concrete. Furthermore, the polished surface of samples extracted from the ties show the uniformity and air void system in some ties which demonstrate their superiority in terms of resistance to freeze-thaw damage. Considering the results of this research, comprehensive evaluation of material characteristics might give a better view of existing concrete railroad ties situation, providing a worthwhile background for future tie design considerations.

    关键字:

  • MATERIAL CHARACTERISTICS EVALUATION OF EXISTING PRE-STRESSED CONCRETE RAILROAD TIES AFTER SERVICE PERIOD

    Aref Shafiei Dastgerdi;Kyle Riding;Robert J. Peterman;B. Terry Beck;

    ASME joint rail conference

    2018年

  • RELATIONSHIPS BETWEEN WHEEL/RAIL SURFACE IMPACT LOADINGS AND CORRESPONDINGLY TRANSMITTED TIE/BALLAST IMPACT PRESSURES FOR REVENUE TRAIN OPERATIONS

    作者:Travis J. Watts;Jerry G. Rose;Ethan J. Russell; 会议名称:ASME joint rail conference 2018年

    A series of specially designed granular material pressure cells were precisely positioned directly below the rail at the tie/ballast interface to measure typical interfacial pressures exerted by revenue freight trains. These vertical pressures were compared to the recorded wheel/rail nominal and peak forces for the same trains traversing nearby mainline wheel impact load detectors (WILDs). The cells were imbedded within the bottom of new wood ties so that the surfaces of the pressure cells were even with the bottoms of the ties and the underlying ballast. The cells were inserted below consecutive rail seats of one rail to record pressures for a complete wheel rotation. The stability and tightness of the ballast support influenced the magnitudes and consistencies of the recorded ballast pressures. Considerable effort was required to provide consistent ballast conditions for the instrumented ties and adjacent undisturbed transition ties. Norfolk Southern (NS) crews surfaced and tamped through the test section and adjacent approach ties. This effort along with normal accruing train traffic subsequently resulted in reasonably consistent pressure measurements throughout the test section. The impact ratio (impact factor) and peak force values recorded by the WILDs compared favorably with the resulting magnitudes of the transferred pressures at the tie/ballast interface. High peak force and high impact ratio WILD readings indicate the presence of wheel imperfections that increase nominal forces at the rail/wheel interface. The resulting increased dynamic impact forces can contribute to higher degradation rates for the track component materials and more rapid degradation rates of the track geometry. The paper contains comparative WILD force measurements and tie/ballast interfacial pressure measurements for loaded and empty trains. Typical tie/ballast pressures for locomotives and loaded freight cars ranges from 20 to 30 psi (140 to 210 kPa) for smooth wheels producing negligible impacts. The effect of increased wheel/rail impacts and peak force values on the correspondingly transmitted pressures at the tie/ballast interface is significant, with increased pressures of several orders of magnitude compared to nominal impact forces from wheels.

    关键字:

  • RELATIONSHIPS BETWEEN WHEEL/RAIL SURFACE IMPACT LOADINGS AND CORRESPONDINGLY TRANSMITTED TIE/BALLAST IMPACT PRESSURES FOR REVENUE TRAIN OPERATIONS

    Travis J. Watts;Jerry G. Rose;Ethan J. Russell;

    ASME joint rail conference

    2018年

  • SIMULATING FOULING MATERIAL TRANSPORT IN BALLAST

    作者:Yu Qian;Yi Wang;Shengwei Zhu;Dimitris C. Rizos; 会议名称:ASME joint rail conference 2018年

    A ballast layer is used to facilitate drainage and load transferring in railroad track structure. With tonnage accumulation, fine materials, such as coal dust, clay, locomotive sand, degraded ballast aggregate, and other small particles, will penetrate into the clean and uniformly graded ballast layer causing contamination, usually referred as fouling. Fouling is unfavorable to railroad track performance due to the reduced drainage and consequent engineering challenges including but not limited to mud pumping, excessive settlement, and reduced bearing capacity. Previous research has investigated the mechanical behavior of the fouled ballast in both the laboratory and the field environment. However, the fundamental mechanism that governs the manner in which the fouling materials are transported and accumulated in the ballast layer is not thoroughly understood. Researchers at the University of South Carolina have initiated the effort to investigate the fouling process in the ballast layer. High-fidelity computational fluid dynamics (CFD) simulation is used to study the fluid flow patterns in order to quantify the transport behavior of the fine particles within the ballast layer and potential impact to the track performance and drainage. Specifically, the ballast layer is treated as a porous material, and the fouling materials are modeled as distinct individual particles to assess the probability of their trajectory location. This paper presents the preliminary results of the simulated path of the fouling materials in the ballast layer under seepage, and demonstrates the capability of the developed algorithm to quantify the effects of the ballast layer characteristics on fouling materials transport. The findings from this study will be beneficial for optimizing shoulder ballast cleaning or undercutting practices.

    关键字:

  • SIMULATING FOULING MATERIAL TRANSPORT IN BALLAST

    Yu Qian;Yi Wang;Shengwei Zhu;Dimitris C. Rizos;

    ASME joint rail conference

    2018年

  • ON THE EFFECTS OF MULTIPLE RAILWAY TRACK ALIGNMENT DEFECTS ON THE CWR THERMAL BUCKLING

    作者:Giovanni Pio Pucillo; 会议名称:ASME joint rail conference 2018年

    The lateral stability of the continuous welded rail (CWR) depends on a number of parameters which contribute to the progressive loss of the initial alignment of the track and its consequent predisposition to deform sideways, gradually or sharply, with serious risks for the safety both of passengers and operators. Different types of initial lateral defect, in terms of shape and size, are introduced by many authors in their own numerical and analytical model, but essentially all of them can be traced back - except for small "personalizations" - to the model proposed by Andrew Kish, who hypothesized the existence of a misalignment defect having the shape of a sine curve extended for half-wavelength, characterized by amplitude and wavelength values typical of the USA railroads. Moreover, all previous studies focused their attention on the introduction, in a geometrically perfect railway track, of a single defect confined in a zone of finite dimensions and having a rather simple geometry which qualitatively approximates the real defect, with the aim of simplifying the calculation of the buckling temperatures of the track associated with such geometry. In this paper, it was preliminarily analyzed the way the defect introduced in the track affects the critical temperature values. It started with a defect created artificially, applying to a geometrically perfect track and in the absence of thermal loads, a lateral displacement in the central transversal section of the track, and calculating, with the hypothesis of linear elastic behavior, the resulting deformed shape, which was assumed, after zeroing the corresponding stress field, as the input geometry for the subsequent buckling calculation. The deformed shape so obtained, being a Zimmermann deformed shape type, has no geometrical discontinuities near the defect and interprets in a natural way the defected geometry of the track, due to the dependence of its configuration on the flexural stiffness of the entire track in the lateral plane. Afterwards, modeling was carried out taking into account the real behavior of the track after the loss of its rectilinear configuration: the defect was created simulating the response of the track to a momentary lateral load - resulting, e.g., from train passages - which succeeded to cause a permanent displacement resulting from the elastic-plastic response of the track. The deformed shape of the track obtained in this way was used as the input geometry for the calculation of the buckling temperatures, once without resetting the stress field induced in the structure by the loading-unloading hysteresis cycle, and then considering the track free from internal stresses. The results show that both the numerical model that contemplate the defect introduced "plastically", and that where the track is free from internal stresses, lead to more conservative results against the risk of thermal buckling in railway tracks made with CWR. A better approximation of the realistic representation of a generic defected railway track was pursued considering an indefinite number of defects distributed along the track, where each defect was characterized by different amplitude and wavelength values. The obtained results show that the presence of multiple defects further reduces the safety factor against the thermal track buckling phenomenon. The paper ends with the proposal of an evaluation criterion that takes into account the effects of multiple alignment defects on the critical buckling temperatures in continuous welded rail tracks.

    关键字:

  • ON THE EFFECTS OF MULTIPLE RAILWAY TRACK ALIGNMENT DEFECTS ON THE CWR THERMAL BUCKLING

    Giovanni Pio Pucillo;

    ASME joint rail conference

    2018年

  • BENEFITS OF PRESTRESSED HSRM CONCRETE TIES FOR CENTER BINDING CONDITIONS

    作者:Adam I. Zeitouni;Dimitris Rizos;Yu Qian; 会议名称:ASME joint rail conference 2018年

    Concrete ties have become a promising alternative to timber ties for freight lines with increased curvature, high annual traffic, and large axle loads. They are also widely adopted in passenger lines. High strength (HS) concrete is the material of choice in the fabrication of prestressed concrete railroad ties. The higher strength of the concrete is directly related to higher values of the Elastic Modulus, thus increasing the rigidity of the material. The combination of increased strength, rigidity, and the material brittleness may lead to the development of high amplitude stresses with high gradients, which appears to be a common underlying cause of premature cracking and deterioration observed in some concrete ties. Realizing the current issues associated with the performance of concrete ties and recalling the findings of an almost fifteen-year-old research conducted at the University of South Carolina (USC), a hypothesis was formulated that there is a potential benefit in introducing weathered granite aggregates into mix designs for railroad concrete ties. A high strength, yet lower rigidity, concrete will reduce the amplitude of the stress field and equally important, will regularize the stress field providing for a smoother load distribution that will diffuse stress concentrations. Consequently, the High Strength Reduced Modulus (HSRM) concrete improves the cracking resistance and fatigue performance, thus extending the life of the tie. A comprehensive research program has been conducted at USC to identify the benefits of using HSRM in concrete ties. The research is based on experimental investigations and computer simulations at the material, component and structural member levels. This work presents the details of the computer simulation studies that pertain to center binding conditions. Three-dimensional nonlinear Finite Element (FE) models have been developed for the HSRM and the "Standard" concrete ties. Nonlinear material models based on damaged plasticity are implemented. The concrete-steel bond interface is also modeled and discussed. Validation of these models is conducted through comparisons with laboratory testing of prestressed concrete prisms, and it has shown excellent accuracy. Subsequently, a study related to center binding conditions in a tangent track have been conducted. These studies showed that the HSRM concrete tie outperformed the Standard concrete tie in these benchmark tests by (ⅰ) showing smoother stress distribution, (ⅱ) delaying the initiation of cracks and (ⅲ) failing at higher ultimate loads. The analysis results are discussed and future recommendations presented.

    关键字:

  • BENEFITS OF PRESTRESSED HSRM CONCRETE TIES FOR CENTER BINDING CONDITIONS

    Adam I. Zeitouni;Dimitris Rizos;Yu Qian;

    ASME joint rail conference

    2018年

  • BALLAST LIFE AND EFFECTIVE PARAMETERS

    作者:Hamed F. Kashani;James P. Hyslip; 会议名称:ASME joint rail conference 2018年

    Railway ballast under repeated traffic loading deforms and deteriorates. Increases in the rate of settlement in ballast decreases its useful life and contributes to geometry roughness and poor ride quality. Based on laboratory and field studies, as well as mechanic-based models, the fouling condition of the ballast has been shown to have a profound effect on settlement and overall ballast life. Quantifying ballast settlement and the effect of maintenance at different stages of ballast life can define the State of Good Repair (SGR) for ballast. This paper presents an approach for predicting ballast life based on geotechnical principles and maintenance management philosophy. Over 200 revenue-service locations have been studied for developing this model for different tracks including mixed passenger and freight as well as only freight traffic. The approach presented in this paper can be used for optimizing ballast's life-cycle costs through a maintenance management approach.

    关键字:

  • BALLAST LIFE AND EFFECTIVE PARAMETERS

    Hamed F. Kashani;James P. Hyslip;

    ASME joint rail conference

    2018年

  • BALL INDENTATION TECHNIQUE TO ESTIMATE FRACTURE TOUGHNESS OF HIGH-STRENGTH RAIL STEELS

    作者:Feng Yu;P.Y. Ben Jar;Michael T. Hendry; 会议名称:ASME joint rail conference 2018年

    In this work, the non-destructive ball indentation technique is applied to estimate fracture toughness for three types of high-strength rail steels based on continuum damage mechanics. Damage parameter, in terms of the deterioration of elastic modulus, is measured for three rail steels using the loading-unloading smooth tensile test, based on which a ductile damage model is calibrated to determine the critical damage parameter at the onset of fracture. Meanwhile, an instrumented ball indentation test is conducted on the three rail steels to generate damage as a function of contact depth under indentation compression. The critical damage parameter from the smooth specimen is then applied to the indentation test to determine the critical contact depth for calculating the indentation fracture toughness based on the concept of indentation energy to fracture. Results show that although the magnitude of the so-determined indentation fracture toughness is greater than that of the corresponding mode I critical stress intensity factor (K_(Ic)) measured using the pre-cracked single-edge-notched bend (SENB) specimen, the former can well predict the ranking order of the K_(Ic) values among the three rail steels.

    关键字:

  • BALL INDENTATION TECHNIQUE TO ESTIMATE FRACTURE TOUGHNESS OF HIGH-STRENGTH RAIL STEELS

    Feng Yu;P.Y. Ben Jar;Michael T. Hendry;

    ASME joint rail conference

    2018年

  • ADVANCES IN FILTRATION IN AUTOMATIC LUBE OIL FILTERS

    作者:Ian Stanley;Stefan Schmitz; 会议名称:ASME joint rail conference 2018年

    In 2006 an automatic lube oil filtration system with an automatic backflushing filter and a centrifuge for diesel locomotives was presented at the ASME Spring Technical Conference. The filter cleans itself continuously and the system can be used instead of conventional disposable paper filters to reduce servicing requirements, improve oil cleanliness and reduce the oil system's exposure to contaminants. In 2015 at the ASME Fall Technical Conference, a development of the system was presented that introduced an electric pump to boost both centrifuge and automatic filter performance at lower engine speeds, as seen during locomotive idling or coasting. The next development addresses the automatic filter mesh, something that has not improved substantially over the last 20 years. The main challenge with improving the mesh for a backflushing filter has been balancing the filtration grade with self-cleaning performance. By going to a finer mesh that catches ever smaller particles, the filter element tends to become more difficult to backflush. For a given wire diameter the free flow area also decreases when the openings become smaller, reducing the maximum mesh loading. Reducing the diameter of the wire used increases the free flow area, but makes the mesh more fragile and difficult to weld. A recent advancement in the mesh design now allows the automatic filter to filter the oil to a much finer degree than was previously possible while maintaining high self-cleaning performance. The filtration performance was evaluated by using the multi-pass method according to ISO 16889, while the backflushing performance was evaluated on our in-house test stand. Currently these elements are being field tested. Being able to filter and separate much smaller particles is expected to reduce long term engine wear and, in certain cases, improve oil life.

    关键字:

  • ADVANCES IN FILTRATION IN AUTOMATIC LUBE OIL FILTERS

    Ian Stanley;Stefan Schmitz;

    ASME joint rail conference

    2018年

  • ELECTRONIC FREIGHT CAR INSPECTION RECORDING AND APPLICATION OF INTERN ET-OF-THINGS (IOT) AND MACHINE-TO-MACHINE (M2M) FRAMEWORKS

    作者:Matthew Cowan;Jacob Cimbalista;Joseph Lieberman;Bryan Schlake; 会议名称:ASME joint rail conference 2018年

    Freight railroad classification yards have been compared to large-scale manufacturing plants, with inbound trains as the inputs and outbound trains as the outputs. Railcars often take up to 24 hours to be processed through a railyard due to the need for manual inbound inspection, car classification, manual outbound inspection, and other intermediate processes. Much of the inspection and repair process has historically been completed manually with handwritten documents. Until recently, car inspections were rarely documented unless repairs were required. Currently, when a defect is detected in the yard, the railcar inspector must complete a "bad order" form that is adhered to each side of the car. This process may take up to ten minutes per bad order. To reduce labor costs and improve efficiency, asset management technology and Internet-of-Things (IoT) frameworks can now be developed to reduce labor time needed to record bad orders, increase inspection visibility, and provide the opportunity to implement analytics and cognitive insights to optimize worker productivity and facilitate condition-based maintenance. The goal of this project is to develop a low-cost prototype electronic freight car inspection tracking system for small-scale (short line and regional) railroad companies. This system allows car inspectors to record mechanical inspection data using a ruggedized mobile platform (e.g. tablet or smartphone). This data may then be used to improve inspection quality and efficiency as well as reduce inspection redundancy. Data collection will involve two approaches. The first approach is the development of an Android-based mobile application to electronically record and store inspection data using a smartphone or rugged tablet. This automates the entire bad order form process by connecting to IBM's Bluemix Cloudant NoSQL database. It allows for the information to be accessed by railroad mechanical managers or car owners, anywhere and at any time. The second approach is a web-based Machine-to-Machine (M2M) system using Bluetooth low energy (BLE) and beacon technology to store car inspection data on a secure website and/or a cloudant database. This approach introduces the freight car inspection process to the "physical web," and it will offer numerous additional capabilities that are not possible with the current radio frequency identification device (RFID) system used for freight car tracking. By connecting railcars to the physical web, railcar specifications and inspection data can be updated in real-time and be made universally available. At the end of this paper, an evaluation and assessment is made of both the benefits and drawbacks of each of these approaches. The evaluation suggests that although some railroads may immediately benefit from these technological solutions, others may be better off with the current manual method until IoT and M2M become more universally accepted within the railroad industry. The primary value of this analysis is to provide a decision framework for railroads seeking to implement IoT systems in their freight car inspection practices. As an additional result, the software and IoT source code for the mobile app developed for this project will be open source to promote future collaboration within the industry.

    关键字:Internet-of-Things; IoT; Physical Web; Railcar Inspection; Freight Car Inspection; Railroad App; Inspection Technology; Machine-to-Machine; M2M

  • ELECTRONIC FREIGHT CAR INSPECTION RECORDING AND APPLICATION OF INTERN ET-OF-THINGS (IOT) AND MACHINE-TO-MACHINE (M2M) FRAMEWORKS

    Matthew Cowan;Jacob Cimbalista;Joseph Lieberman;Bryan Schlake;

    ASME joint rail conference

    2018年

  • IMPROVING COLLISION POST CRASHWORTHINESS OF LEGACY LOCOMOTIVES

    作者:Jeff Gordon;Matthew Radovich;Srini Swamy;Anand Prabhakaran;Sabri Cakdi;Som P. Singh; 会议名称:ASME joint rail conference 2018年

    Modern freight locomotives are built to crashworthiness standards that are defined in Subpart D of Code of Federal Regulations (CFR) Part 229 and Association of American Railroads (AAR) S-580 standards. The first freight locomotive crashworthiness standard, AAR S-580, was released in 1989 and became effective as of August 1990. Locomotives that were manufactured before the 1990, so-called "legacy", lack the crew protection offered by the modern "crashworthy" locomotives. While legacy locomotives, such as narrow-nose designs that were manufactured before 1990s, are generally relegated to non-lead locomotive service in Class I railroads, these units are sometimes used in mainline service. Even though the number of narrow-nose locomotives has declined, there remains a risk of injuries and fatalities for the crew for the next several years. The scope of this study is the following; 1. The assessment of injuries and fatalities from collisions involving legacy locomotives, 2. The crashworthiness evaluation of collision posts for a sample legacy (narrow-nose, legacy) locomotive assembled in the 1960s and rebuilt in 2001, 3. Analysis of alternative collision post designs to meet and exceed the collision post requirements in the 2001 version of AAR S-580.

    关键字:

  • IMPROVING COLLISION POST CRASHWORTHINESS OF LEGACY LOCOMOTIVES

    Jeff Gordon;Matthew Radovich;Srini Swamy;Anand Prabhakaran;Sabri Cakdi;Som P. Singh;

    ASME joint rail conference

    2018年

  • RECEIVER OPERATING CHARACTERISTIC (ROC) ANALYSIS ON THE WHEEL IMPACT LOAD DETECTOR SYSTEM OF METRO-NORTH RAILROAD

    作者:Monique Stewart;Hamed Pouryousef;Brian Marquis;Som P. Singh;Demet Cakdi; 会议名称:ASME joint rail conference 2018年

    The Federal Railroad Administration (FRA) has partnered with Metro-North Railroad (MNR), Long Island Rail Road (LIRR) and New York & Atlantic Railway (NYA) to enhance operational safety through the implementation of wayside detection systems. Currently, MNR has a four-track Wheel Impact Load Detector (WILD) system that has been operating since 2010 near the Grand Central Terminal. This paper discusses a Receiver Operating Characteristic (ROC) analysis of this existing WILD system in conjunction with the wheel maintenance practices since 2010. Currently MNR's operating procedures require a car with wheel(s) exhibiting a vertical peak load/mean load ratio, called dynamic ratio (DR), ≥3.0 to be shopped for repair. The analysis, using a 30-day repair window after detection, shows that 84% of the cars shopped for wheel(s) with DR≥3.0 required valid maintenance repairs. The minimum number of total false records (false positive + false negative records, combined) were observed within the DR range of 2.7-2.8 when considering wheel flat defects only. An analysis of the false negative records inclusive of both flat and shell spots, showed that the minimum number of false records dropped slightly to a DR range of 2.6-2.7. The reported ROC analysis shows that MNR's current DR≥3.0 to trigger inspection and maintenance actions is reasonable.

    关键字:Wheel Impact Load Detector (WILD); Dynamic Ratio; Receiver Operating Characteristic (ROC); False Positive; False Negative; Truing; Wheel Defects; Flat Snots. Shell Snots. Wheel Inspection

  • RECEIVER OPERATING CHARACTERISTIC (ROC) ANALYSIS ON THE WHEEL IMPACT LOAD DETECTOR SYSTEM OF METRO-NORTH RAILROAD

    Monique Stewart;Hamed Pouryousef;Brian Marquis;Som P. Singh;Demet Cakdi;

    ASME joint rail conference

    2018年

  • DEFECT PROGNOSTICS MODELS FOR SPALL GROWTH IN RAILROAD BEARING ROLLING ELEMENTS

    作者:Nancy De Los Santos;Robert E. Jones;Constantine M. Tarawneh;Arturo Fuentes; 会议名称:ASME joint rail conference 2018年

    Prevention of railroad bearing failures, which may lead to catastrophic derailments, is a central safety concern. Early detection of railway component defects, specifically bearing spalls, will improve overall system reliability by allowing proactive maintenance cycles rather than costly reactive replacement of failing components. A bearing health monitoring system will provide timely detection of flaws. However, absent a well verified model for defect propagation, detection can only be used to trigger an immediate component replacement. The development of such a model requires that the spall growth process be mapped out by accumulating associated signals generated by various size spalls. The addition of this information to an integrated health monitoring system will minimize operation disruption and maintain maximum accident prevention standards enabling timely and economical replacements of failing components. An earlier study done by the authors focused on bearing outer ring (cup) raceway defects. The developed model predicts that any cup raceway surface defect (i.e. spall) once reaching a critical size (spall area) will grow according to a linear correlation with mileage. The work presented here investigates spall growth within the inner rings (cones) of railroad bearings as a function of mileage. The data for this study were acquired from defective bearings that were run under various load and speed conditions utilizing specialized railroad bearing dynamic test rigs owned by the University Transportation Center for Railway Safety (UTCRS) at the University of Texas Rio Grande Valley (UTRGV). The experimental process is based on a testing cycle that allows continuous growth of railroad bearing defects until one of two conditions are met; either the defect is allowed to grow to a size that does not jeopardize the safe operation of the test rig, or the change in area of the spall is less than 10% of its previous size prior to the start of testing. The initial spall size is randomly distributed as it depends on the originating defect depth, size, and location on the rolling raceway. Periodic removal and disassembly of the railroad bearings was carried out for inspection and defect size measurement along with detailed documentation. Spalls were measured using optical techniques coupled with digital image analysis, as well as, with a manual coordinate measuring instrument with the resulting field of points manipulated in MatLab™. Castings were made of spalls using low-melting, zero-shrinkage bismuth-based alloys, so that a permanent record of the spall geometry and its growth history can be retained. The main result of this study is a preliminary model for spall growth, which can be coupled with bearing condition monitoring tools that will allow economical and effective scheduling of proactive maintenance cycles that aim to mitigate derailments, and reduce unnecessary train stoppages and associated costly delays on busy railways.

    关键字:

  • DEFECT PROGNOSTICS MODELS FOR SPALL GROWTH IN RAILROAD BEARING ROLLING ELEMENTS

    Nancy De Los Santos;Robert E. Jones;Constantine M. Tarawneh;Arturo Fuentes;

    ASME joint rail conference

    2018年

  • IMPROVED TRUCK CASTINGS

    作者:Kerry Jones;Matt DeGeorge;Monique Stewart; 会议名称:ASME joint rail conference 2018年

    This paper examines alternative, improved materials for truck castings. The first part looks at steels that would not require post-weld heat treatment after repair welding. The second part investigates specific applications for temperatures below -50℉. The rapid, dramatic temperature changes that occur during welding can form brittle phases or cracking in some steels. The weld has three areas of differing structure: the weld, the heat affected zone (HAZ), and the parent metal. The maximum hardness occurs in the HAZ and is the limiting factor in determining weldability. An ultraweldable steel is a steel that does not require post-weld heat treatment. Many steels were evaluated for their chemical composition and susceptibility to cracking; those that were likely to form brittle phases were eliminated from consideration. Four low alloy steels and one carbon steel were selected as being potentially ultraweldable. To evaluate the ultraweldability of these steels, groove welds and two types of spot welds were made on the five candidate alloys. The welds were then sectioned and prepared for microstructural and microhardness evaluation. Microhardness readings were taken across the weld, spanning the weld, HAZ, and base material. Three of the steels formed hard, brittle phases during most of the tests. This indicates these materials are not ultraweldable. Two of the low alloy steels did meet the requirements for ultraweldability. Future work in this area would include producing truck castings from these materials. At low temperatures, plain carbon steels, such as the types used in truck castings, can fracture in a brittle manner, with no visible deformation. The material property of deforming without fracture is toughness or ductility. Using materials that retain their toughness in low temperatures could prevent brittle failures of truck castings. Six grades of steel currently used in low temperature applications were selected for this research. Specimens from each of the six materials were evaluated for tensile properties at multiple temperatures. Charpy impact specimens were tested at temperatures ranging from -20 ℉ to -120℉. The measured room temperature tensile properties of each of the six steels met or exceeded the requirements for Grade B+, the steel currently used for truck castings. Four of the steels showed impact energies far above that of the current Grade B+, but two of them gave consistently higher impact energies than all others. These would be the best candidates for future work in this area. Future work would involve producing full size truck castings from one or more of these alloys, then testing them for fatigue performance, preferably at low temperatures.

    关键字:

  • IMPROVED TRUCK CASTINGS

    Kerry Jones;Matt DeGeorge;Monique Stewart;

    ASME joint rail conference

    2018年

  • ACCIDENT/INCIDENT RECONSTRUCTION AND VISUALIZATION

    作者:Kevin J. Renze; 会议名称:ASME joint rail conference 2018年

    Factual evidence from locomotive event data recorders (EDR), locomotive image data recorders, accident site surveys, witness marks, rail equipment, track structure, photographs, video cameras, AEI readers, hot wheel or hot bearing detectors, wayside signal bungalows, train consist documents, and radio communication is integrated, validated, and visualized in a three-dimensional model environment. The goal is to build a physics-based, data-driven model of train position as a function of time to enhance the documentation, investigation, understanding, and analysis of in-service train derailments. Methods to construct, validate, and interrogate time-accurate, interactive visualizations of train movements for partial and complete train consists are discussed and demonstrated. In-service freight train derailments that occurred in Hoxie, Arkansas (offset frontal collision between opposing freight trains), Casselton, North Dakota (unit grain train derailment with car fouling opposing mainline track and subsequent crude oil unit train head-on collision), and Graettinger, Iowa (unit ethanol train derailment) are used to illustrate the accident reconstruction method. Similar vehicle path reconstructions for recent highway, aviation, and marine investigations are also presented.

    关键字:

  • ACCIDENT/INCIDENT RECONSTRUCTION AND VISUALIZATION

    Kevin J. Renze;

    ASME joint rail conference

    2018年

服务协议

服务协议


掌桥科研助手微信平台(简称“本平台”)外文文献服务的所有权和运营权归属六维联合信息科技(北京)有限公司(简称“六维联合”)。在购买本平台外文文献服务前,请您仔细阅读本服务协议的如下全部内容,以便您决定是否继续购买本平台的服务,您的继续购买行为即表示您已经完全理解并接受本服务协议,并同意受其约束。若您不同意本服务协议,请勿购买本平台的服务。

1.服务说明

(1)要成为系统服务用户必须自行配备上网的所需设备,包括个人微信使用终端、调制解调器或其他必备上网装置,并自行负担个人上网所支付的与此服务有关的网络费用;

(2)用户应向本平台上提供单位名称、姓名、电子邮箱、手机号码,通过手机验证后才能收到外文文献电子邮件;

(3)除按照国家法律法规、第三方(本服务中指国家工程技术图书馆)和本服务要求提供用户的个人资料外,本平台不额外要求用户提供个人隐私信息;

(4)外文文献一经购买,无论用户是否实际使用,不得退款;

(5)外文文献原文是由国家工程技术图书馆负责提供。

2.合理使用

根据相关法律规定,本平台及其所提供的外文期刊、外文会议、外文学位论文和外文科技报告文献仅供购买服务的用户(即授权用户)为个人目的或课堂教学目的使用,授权用户可以对本平台的文献进行以下合理使用:

(1)通过安全网络访问服务器对网络数据库进行检索;

(2)以个人研究和学习为目的,在线阅读检索结果;

(3)通过文献传递获取电子文献供授权用户个人研究和学习使用;

(4)非以商业营利为目的承担正常教学任务的授权用户,为教学需要,可少量复制文献供教学人员使用,同时应指明作者姓名和文献名称。例如授权用户可少量复制作为教学参考资料的文献供从事课堂教授的教师使用,可少量文献复制到供本单位教学使用的内部网络中的安全计算机上,供选修特定课程的学生在该课程课堂教学期间和地点通过内部网络进行阅读。

3.侵权行为

除上述合理使用方式外,不得以任何方式对本平台全部或者部分文献进行复制、出版、发行、传播、转让、商业或其他开发,授权用户以下(但不仅限于以下)超出合理使用范围的行为,属侵犯知识产权行为,须严格禁止:

(1)把外文文献以公共方式提供给非授权用户使用;

(2)利用外文文献对非授权用户提供文献服务;

(3)利用外文文献进行商业服务或支持商业服务;

(4)利用外文文献内容汇编生成二次产品,提供公共或商业服务;

(5)将外文文献使用在任何其他网站或计算机联网环境中,包括但不仅限于在国际互联网和万维网站上。

4.侵权责任

授权用户应在法律规定的其超出合理使用范围内使用本平台提供的文献,若因授权用户的侵权使用行为被相关权利人主张权利而产生任何纠纷、仲裁、诉讼,或遭到国家相关部门处理,由授权用户承担全部法律责任并使本平台方免责,授权用户还应赔偿因上述原因给本平台方造成的全部直接和间接损失,包括但不限于律师费用、诉讼及仲裁费用、财务费用及差旅费等。一经发现用户的使用情况超出著作权法规定的合理使用范围,本平台有权立即封禁该用户的服务账户,并有权终止向用户提供本协议约定的服务而无须承担违约责任。

5.免责声明

(1)本平台仅为根据您的搜索指令提供搜索服务、数据链接服务和电子邮件原文传递服务,搜索结果和原文数据均来自第三方网站,六维联合不会对第三方网站内容作任何实质性的编辑、整理、修改;

(2)本平台对服务及服务所涉文献信息不作任何明示或暗示的保证,包括但不限于服务一定会满足用户的使用要求、服务的及时性、持续性、安全性、准确性以及服务所涉及文献的准确性、完整行、可靠性;

(3)本平台不保证所提供的服务和服务所涉文献信息来源客观准确,对于任何因信赖或使用获取的文献信息,而给用户造成任何直接或间接损失,本平台均不承担责任;本平台不因用户与任何第三方产生的争议或诉讼承担任何责任。

(4)用户签署本协议即意味着理解且不要求六维联合在发生不可抗力情况下承担责任。不可抗力是指不能合理控制、不可预见或即使预见亦无法避免的事件,包括但不限于政府行为、地震、台风、洪水、火灾或其它天灾、战争或任何其它类似事件。鉴于互联网之特殊性质,不可抗力还包含非因本平台原因导致本服务无法正常运行、服务中断或延迟的情形,包括黑客攻击,电信部门技术调整导致之重大影响,因政府管制而造成之暂时关闭,病毒侵袭,网站升级、系统停机维护或通讯终端、电信设备出现故障导致无法进行数据传输等。

6.其他规定

(1)本协议内容受中华人民共和国法律的约束。如果本协议中任何规定被裁定为无效或不可强制执行,该项规定应被撤销,而其余规定继续有效。

(2)本协议的最终解释权归六维联合。

(3)本协议条款可由六维联合随时全部或部分转让。未经六维联合事先明确书面同意,用户不得以任何方式转让本协议条款。

注意:六维联合未就您或其他人士的某项违约行为采取行动,并不表明六维联合就任何继后或类似的违约事件放弃采取行动的权利。


我已阅读并同意《服务协议》