Gauging of Concrete Crossties to Investigate Load Path in Laboratory and Field Testing

2014 ◽  
Author(s):  
Sihang Wei ◽  
Daniel A. Kuchma ◽  
J. Riley Edwards ◽  
Marcus S. Dersch ◽  
Ryan G. Kernes
Keyword(s):  
High Speed ◽  
Field Experiments ◽  
Vertical Direction ◽  
Field Testing ◽  
Longitudinal Axis ◽  
Load Cell ◽  
Strain Gauges ◽  
Vertical Load ◽  
Load Path ◽  
Transportation Research

To meet the demands of increasing freight axle loads and cumulative gross tonnages, as well as high-speed passenger rail development in North America, the performance and service life of concrete railway crossties must be improved. As a part of a study funded by the Federal Railroad Administration (FRA) aimed at improving concrete crossties and fastening systems, laboratory experimentation was performed at the Advanced Transportation Research Engineering Laboratory by researchers from the University of Illinois at Urbana-Champaign. This paper focuses on the behavior of concrete cross-ties as well as characterizing and quantifying the loads transmitted from the wheel/rail interface through the fastening system to the tie in the vertical direction. Concrete embedment strain gauges were cast below rail seat to create a “load cell” to measure the rail seat vertical load. Laboratory instrumentation efforts have been done to calibrate this vertical “load cell”. To understand the rail seat load and load path in the field, experimentation was performed at the Transportation Technology Center (TTC) in Pueblo, both static loading which were applied by TTC’s Track Loading Vehicle and dynamic loading due to real wheel-rail interaction were discussed. Concrete cross-tie bending behavior was also investigated through the use of strain gauges applied in the longitudinal axis of the crossties in both laboratory and field experiments. Results from these findings will be utilized to aid in the recommendations for the mechanistic design of various components within the fastening system.

Vertical Load Path Under Static and Dynamic Loads in Concrete Crosstie and Fastening Systems

2014 ◽  
Author(s):  
Kartik R. Manda ◽  
Marcus Dersch ◽  
Ryan Kernes ◽  
Riley J. Edwards ◽  
David A. Lange
Keyword(s):  
Vertical Direction ◽  
Dynamic Loads ◽  
Vertical Load ◽  
Load Path ◽  
Test Program ◽  
Static Loads ◽  
Extensive Field ◽  
Interface Characteristics ◽  
Static And Dynamic Loads ◽  
Insight Into

An improved understanding of the vertical load path is necessary for improving the design methodology for concrete crossties and fastening systems. This study focuses on how the stiffness, geometry, and interface characteristics of system components affect the flow of forces in the vertical direction. An extensive field test program was undertaken to measure various forces, strains, displacements and rail seat pressures. A Track Loading Vehicle (TLV) was used to apply well-calibrated static loads. The TLV at slow speeds and moving freight and passenger consists at higher speeds were used to apply dynamic loads. Part of the analysis includes comparison of the static loads and the observed dynamic loads as a result of the trains passing over the test section at different speeds. This comparison helps define a dynamic loading factor that is needed for guiding design of the system. This study also focuses on understanding how the stiffness of the components in the system affects the flow of forces in the vertical direction. The study identifies that the stiffness of the support (ballast) underneath the crossties is crucial in determining the flow of forces. The advances made by this study provide insight into the loading demands on each component in the system, and will lead to improvements in design.

Field Testing of Concrete Crossties and Fastening Systems for the Understanding of Mechanistic Behavior

2013 ◽  
Author(s):  
J. Grassé ◽  
D. Lange
Keyword(s):  
High Speed ◽  
Field Testing ◽  
Element Model ◽  
Future Research ◽  
Load Path ◽  
High Speed Rail ◽  
Railway Infrastructure ◽  
Field Experimentation ◽  
And Performance ◽  
The University

To adequately satisfy the demands placed on North America’s railway infrastructure through ever increasing freight tonnages and development of its high speed rail program, the design and performance of concrete ties and elastic fastening systems must be improved. As a part of a study funded by the Federal Railroad Administration (FRA) aimed at improving concrete crossties and fastening systems, field experimentation was performed at the Transportation Technology Center (TTC) in Pueblo, CO by researchers from the University of Illinois at Urbana-Champaign (UIUC). This paper details the extensive instrumentation program which includes strain gages and linear potentiometers. Testing was conducted over seven adjacent concrete crossties in tangent and curve track utilizing TTC’s Track Loading Vehicle (TLV) as well as passenger and freight train consists. Measurements taken consisted of the wheel-rail input loads, component stresses (e.g. insulator post compression), concrete tie strains, and displacements of the rail and concrete tie. The data was collected synchronously to provide a means to capture the load path, target areas of uncertainty, and provide comprehensive data for the validation of a multi-tie, 3-D finite element model being developed by UIUC. Varying train speeds, track curvature, and loading types provided a means to assess the loading variability that can be expected within the fastening system and lead to more purposeful and efficient instrumentation strategies. Furthermore, this data can be used to guide future research in further quantifying the field loading demands on system components, ultimately leading to the mechanistic design of the concrete crosstie and fastening system.

A Method of Obtaining Detailed Freight Car Truck Loading Data

1980 ◽  
Vol 102 (2) ◽  
pp. 151-158
Author(s):  
C. P. Spencer ◽  
T. L. Pitchford
Keyword(s):  
Load Cell ◽  
Vertical Load ◽  
Car Body ◽  
Service Testing ◽  
Sample Data ◽  
Actual Service ◽  
Truck Loading ◽  
Freight Car

A method of obtaining freight car truck loading data utilizing a strain gaged truck bolster as a load cell is described. Analysis necessary to derive both the magnitude and location of the line of action of the freight car body vertical load resultant is presented. Techniques for cycle counting applicable to fatigue studies are suggested. Sample data from actual service testing are presented.

scholarly journals World Experience in Creating Mathematical Models of Air Springs: Advantages and Disadvantages

2021 ◽  
pp. 25-42
Author(s):  
A. Y Kuzyshyn ◽  
S. A Kostritsia ◽  
Yu. H Sobolevska ◽  
А. V Batih
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Mathematical Models ◽  
Dynamic Behavior ◽  
High Speed ◽  
Vertical Direction ◽  
Rolling Stock ◽  
Air Spring ◽  
Advantages And Disadvantages ◽  
Mechanical Models

Purpose. Taking into account the production and commissioning of modern high-speed rolling stock, the authors are aimed to analyze the currently created mathematical models describing the dynamic behavior of the air spring, systematize them and consider the advantages and disadvantages of each model type. Methodology. For the analysis, a comparative chronological method was used, which makes it possible to trace the development of several points of view, concepts, theories. In accordance with the adopted decision equations, the existing models of air springs were divided into three groups: mechanical, thermodynamic and finite-elements. When analyzing mathematical models, the influence of a number of parameters on the dynamic behavior of the air spring, such as disturbing force frequency, heat transfer, nonlinear characteristics of materials, the shape of the membrane, etc., was considered. Findings. A feature of mechanical models is the determination of input parameters based on the analysis of experimental results, requires access to complex measuring equipment and must be performed for each new model of an air spring separately. Unlike mechanical models, which allow taking into account the damping effect of an air spring in the horizontal and vertical direction, thermodynamic models are mainly focused on studying the dynamic behavior of an air spring in the vertical direction. The use of the finite element method makes it possible to most accurately reproduce the dynamic behavior of an air spring, however, it requires significant expenditures of time and effort to create a finite element model and perform calculations. Originality. Mathematical models of the dynamic behavior of an air spring are systematized, and the importance of their study in conjunction with a spatial mathematical model of high-speed rolling stock is emphasized. Practical value. The analysis of the mathematical models of the dynamic behavior of the air spring shows the ways of their further improvement, indicates the possibility of their use in the spatial mathematical model of the rolling stock in accordance with the tasks set. It will allow, even at the design stage of high-speed rolling stock, to evaluate its dynamic characteristic and traffic safety indicators when interacting with a railway track.

scholarly journals Kinematics and Injury Analysis of Front and Rear Child Pillion Passenger in Motorcycle Crash

2018 ◽  
Vol 15 (3) ◽  
pp. 5522-5534 ◽  
Author(s):  
Saiprasit Koetniyom ◽  
J. Carmai ◽  
K. A. A. Kassim ◽  
Y. Ahmad
Keyword(s):  
Head Injury ◽  
High Speed ◽  
Severe Head Injury ◽  
Longitudinal Axis ◽  
Upper Body ◽  
Accelerometer Data ◽  
Neck Injuries ◽  
Car Crash ◽  
Set Up ◽  
Crash Tests

The purpose of this work is to study the kinematics and injury of child pillion passenger from motorcycle-to-car crash tests. Two crash tests for rear and front child pillions were set up. The kinematics of dummies were analysed from accelerometer data and high speed camera pictures. The kinematics and injury mechanisms of the child passenger from both tests are significantly different. For the rear child pillion test, the rider impacted the car before the child passenger. Both rider and child were ejected upward. The child’s head motion was curvilinear towards the car structure. This results in severe head injury due to high HIC. The child sitting at front translated in the longitudinal axis of the motorcycle and impacted the car before the rider. The child’s torso strongly hit to the handlebar first then head hit the car. This results in low value of HIC. The child’s upper-body including neck were compressed between the car and the rider’s torso leading to high risk of severe thorax and neck injuries. The results reveal that the child sitting behind the rider has higher risk of severe head injury while the child sitting before the rider has higher risk of thorax and neck injuries. 

scholarly journals Turbulent channel flow over an anisotropic porous wall – drag increase and reduction

2018 ◽  
Vol 842 ◽  
pp. 381-394 ◽  
Author(s):  
Marco E. Rosti ◽  
Luca Brandt ◽  
Alfredo Pinelli
Keyword(s):  
Drag Reduction ◽  
Channel Flow ◽  
High Speed ◽  
Vertical Direction ◽  
Porous Wall ◽  
Turbulent Channel Flow ◽  
Spanwise Direction ◽  
Normal Velocity ◽  
Porous Walls ◽  
The One

The effect of the variations of the permeability tensor on the close-to-the-wall behaviour of a turbulent channel flow bounded by porous walls is explored using a set of direct numerical simulations. It is found that the total drag can be either reduced or increased by more than 20 % by adjusting the permeability directional properties. Drag reduction is achieved for the case of materials with permeability in the vertical direction lower than the one in the wall-parallel planes. This configuration limits the wall-normal velocity at the interface while promoting an increase of the tangential slip velocity leading to an almost ‘one-component’ turbulence where the low- and high-speed streak coherence is strongly enhanced. On the other hand, strong drag increase is found when high wall-normal and low wall-parallel permeabilities are prescribed. In this condition, the enhancement of the wall-normal fluctuations due to the reduced wall-blocking effect triggers the onset of structures which are strongly correlated in the spanwise direction, a phenomenon observed by other authors in flows over isotropic porous layers or over ribletted walls with large protrusion heights. The use of anisotropic porous walls for drag reduction is particularly attractive since equal gains can be achieved at different Reynolds numbers by rescaling the magnitude of the permeability only.

The Development of Turboexpander-Generators for Gas Pressure Letdown Part I: Design and Analysis

2021 ◽  
Author(s):  
Rasish Khatri ◽  
Jeremy Liu ◽  
Freddie Sarhan ◽  
Ovais Najeeb ◽  
Hiroshi Kajita ◽  
...  
Keyword(s):  
High Speed ◽  
Field Testing ◽  
Magnetic Bearing ◽  
Gas Pressure ◽  
Loop Dynamics ◽  
Full Speed ◽  
Detailed Simulation ◽  
Bearing Design ◽  
Net Load

Abstract This paper describes the design and development of an innovative 280 kW and a 125 kW Turboexpander Generator (TEG) for natural gas pressure letdown (PLD) applications. The flange-to-flange TEG is supported by active magnetic bearings (AMB) and uses an advanced thrust balancing scheme to minimize the net load on the thrust bearing. The machine designs for the two TEG frame sizes are very similar to maintain commonality between parts. A review of the high-speed generator (HSG) and AMB design is provided. A complete AMB closed-loop dynamics study is presented, including a comprehensive rotordynamics and controls analysis. The touchdown bearing design is shown and discussed, and design details of the touchdown bearing resilient mount are presented. The touchdown bearings are given resilience with a tolerance ring. A detailed simulation of a rotor touchdown event at full speed is shown. The magnetic bearing controller (MBC) and variable speed drive (VSD) are located approximately 35 m from the TEG, exposed to the outside environment, and are not required to be explosion-proof. The prototype TEGs are intended to be manufactured and tested in Q1 2021. They will be commissioned, and field tested in Q2 2021. A follow-up paper detailing the mechanical testing and field testing of the units will follow in 2022.

WATER FLOWS AROUND THE COMB PLATES OF THE CTENOPHORE PLEUROBRACHIA PLOTTED BY COMPUTER: A MODEL SYSTEM FOR STUDYING PROPULSION BY ANTIPLECTIC METACHRONISM

1993 ◽  
Vol 177 (1) ◽  
pp. 113-128 ◽  
Author(s):  
D. Barlow ◽  
M. A. Sleigh ◽  
R. J. White
Keyword(s):  
Computer Program ◽  
Water Flow ◽  
High Speed ◽  
Beat Frequency ◽  
Longitudinal Axis ◽  
Model System ◽  
The Other ◽  
Contour Maps ◽  
Water Flows ◽  
Pleurobrachia Pileus

Patterns of water flow around steadily beating comb plates of Pleurobrachia pileus were tracked using suspended plastic beads. The positions of the beads and the comb plates in the plane of the central longitudinal axis of the comb row were digitised from high-speed cine films covering several beat cycles. All of the data from each sequence were combined using a computer program which integrated them into a standard cycle, and the resulting data were plotted by a second computer program to produce charts for different stages in the beat cycle showing the flow velocity at a grid of points. On these charts, contour maps were drawn to indicate the speed and direction of the water flow. Water is drawn towards each comb row from ahead and from the sides and accelerates strongly backwards in a fairly narrow stream which joins those from the other seven comb rows at the rear of the animal. At a beat frequency of 10 Hz the comb plates move with a tip speed of up to 70 mm s-1 in their effective stroke; they have an estimated Reynolds number of 9 in this stroke. Changes in inter- plate volume between adjacent antiplectically coordinated plates are very important in propulsion, particularly near the end of the effective stroke when pairs of adjacent plates close together and cause the high-speed water from around the ciliary tips to be shed into the overlying stream as a series of jets at speeds of 50 mm s-1 or more. The antiplectic coordination of the comb plates makes a major contribution to the efficiency of propulsion.

Development of Magnetic Field-Assisted Single-Point Incremental Forming

2021 ◽  
Vol 883 ◽  
pp. 189-194
Author(s):  
Marco Gucciardi ◽  
Derrick Benson ◽  
Livan Fratini ◽  
Gianluca Buffa ◽  
Hitomi Yamaguchi
Keyword(s):  
Magnetic Field ◽  
Magnetic Force ◽  
Incremental Forming ◽  
Single Point ◽  
Vertical Direction ◽  
Aluminum Sheet ◽  
Single Point Incremental Forming ◽  
Vertical Load ◽  
Localized Deformation ◽  
Physical Interference

Single Point Incremental Forming (SPIF) has recently introduced the concept of material formability enhancement through localized deformation. Since material is processed by means of a pin tool attached to spindle, physical interference (especially in vertical direction) limits attainable shapes with the conventional process. The aim of the following work is to increase the variety of achievable geometries with SPIF through in-process magnetic field assistance. An innovative configuration managing SPIF tool movement using magnetic force is proposed. With this in mind, a magnet configuration was designed to generate a vertical load able to plastically deform a 0.5 mm thick AA1100 aluminum sheet. Experiments were carried out to prove the concept by manufacturing a truncated cone; the results demonstrated the feasibility of Magnetic Field-Assisted SPIF.

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