scholarly journals Rail Car Impact Tests With Steel Coil: Collision Dynamics

Joint Rail ◽  
2003 ◽  
Author(s):  
Karina Jacobson ◽  
David Tyrell ◽  
Benjamin Perlman
Keyword(s):  
Three Dimensional ◽  
Full Scale ◽  
Dynamic Responses ◽  
Lumped Parameter Model ◽  
Collision Dynamics ◽  
Dynamics Model ◽  
Steel Coil ◽  
Impact Tests ◽  
Lumped Parameter ◽  
Grade Crossing

Two full-scale oblique grade-crossing impact tests were conducted in June 2002 to compare the crashworthiness performance of alternative corner post designs on rail passenger cab cars. On June 4, 2002 a cab car fitted with an end structure built to pre-1999 requirements impacted a steel coil at approximately 14 mph. Following, on June 7, 2002 a cab car fitted with an end structure built to current requirements underwent the same test. Each car was equipped with strain gauges, string potentiometers and accelerometers to measure the deformation of specific structural elements, and the longitudinal, lateral and vertical displacements of the car body. The gross motions of the cars and steel coil, the force/crush behavior of the end structures, and the deformation of major elements in the end structures were measured during the tests. During the first test, the car fitted with the 1990’s design end structure acquired more than 20 inches of longitudinal deformation causing failure at the corner post and resulting in the loss of operator survival space. During the second test, the corner post on the car fitted with the State-of-the-Art design deformed longitudinally by about 8 inches, causing no failure and consequently preserving the survivable operator volume. In both cases, the steel coil was thrown to the side of the train after impacting the end structure. Prior to the tests, the crush behaviors of the cars and their dynamic responses were simulated with car crush and collision dynamics models. The car crush model was used to determine the force/crush characteristics of the corner posts, as well as their modes of deformation. The collision dynamics model was used to predict the extent of crush of the corner posts as functions of impact velocity, as well as the three-dimensional accelerations, velocities, and displacements of the cars and coil. Both models were used in determining the instrumentation and its locations. This paper describes the collision dynamics model and compares predictions for the gross motions of the cars and coils made with this model with measurements from the tests. A companion paper describes the car crush model and compares predictions made of car crush with measurements from the test. The collision dynamics was analyzed using a lumped-parameter model, with non-linear stiffness characteristics. The suspension of the car is included in the model in sufficient detail to predict derailment. The model takes the force/crush characteristic developed in the car crush analysis as input, and includes the lateral force that develops as the corner post is loaded longitudinally. The results from the full-scale grade-crossing impact tests largely agree with and confirm the preliminary results of the three-dimensional lumped parameter computer model of the collision dynamics. The predictions of the model for the three-dimensional accelerations, velocities, and displacements of the car and the coil are in very close agreement with the measurements made in the tests of both cars, up to the time of failure of the corner post. The cars remained on the track in both tests, as predicted with the model.

Analyses of Full-Scale Tank Car Shell Impact Tests

2007 ◽  
Author(s):  
Y. H. Tang ◽  
H. Yu ◽  
J. E. Gordon ◽  
M. Priante ◽  
D. Y. Jeong ◽  
...  
Keyword(s):  
Finite Element ◽  
Test Data ◽  
Three Dimensional ◽  
Full Scale ◽  
Collision Dynamics ◽  
Dynamics Modeling ◽  
Dynamics Model ◽  
Rigid Plastic ◽  
Element Analysis ◽  
Closed Form Solutions

This paper describes analyses of a railroad tank car impacted at its side by a ram car with a rigid punch. This generalized collision, referred to as a shell impact, is examined using nonlinear (i.e., elastic-plastic) finite element analysis (FEA) and three-dimensional (3-D) collision dynamics modeling. Moreover, the analysis results are compared to full-scale test data to validate the models. Commercial software packages are used to carry out the nonlinear FEA (ABAQUS and LS-DYNA) and the 3-D collision dynamics analysis (ADAMS). Model results from the two finite element codes are compared to verify the analysis methodology. Results from static, nonlinear FEA are compared to closed-form solutions based on rigid-plastic collapse for additional verification of the analysis. Results from dynamic, nonlinear FEA are compared to data obtained from full-scale tests to validate the analysis. The collision dynamics model is calibrated using test data. While the nonlinear FEA requires high computational times, the collision dynamics model calculates gross behavior of the colliding cars in times that are several orders of magnitude less than the FEA models.

scholarly journals A Collision Dynamics Model of a Multi-Level Train

2006 ◽  
Author(s):  
Michelle Priante ◽  
David Tyrell ◽  
Benjamin Perlman
Keyword(s):  
Three Dimensional ◽  
Design Parameters ◽  
Collision Dynamics ◽  
Dynamics Model ◽  
Single Level ◽  
High Speeds ◽  
Front End ◽  
Multi Level ◽  
Low Speeds ◽  
Vertical Accelerations

In train collisions, multi-level rail passenger vehicles can deform in modes that are different from the behavior of single level cars. The deformation in single level cars usually occurs at the front end during a collision. In one particular incident, a cab car buckled laterally near the back end of the car. The buckling of the car caused both lateral and vertical accelerations, which led to unanticipated injuries to the occupants. A three-dimensional collision dynamics model of a multi-level passenger train has been developed to study the influence of multi-level design parameters and possible train configuration variations on the reactions of a multi-level car in a collision. This model can run multiple scenarios of a train collision. This paper investigates two hypotheses that could account for the unexpected mode of deformation. The first hypothesis emphasizes the non-symmetric resistance of a multi-level car to longitudinal loads. The structure is irregular since the stairwells, supports for tanks, and draglinks vary from side to side and end to end. Since one side is less strong, that side can crush more during a collision. The second hypothesis uses characteristics that are nearly symmetric on each side. Initial imperfections in train geometry induce eccentric loads on the vehicles. For both hypotheses, the deformation modes depend on the closing speed of the collision. When the characteristics are non-symmetric, and the load is applied in-line, two modes of deformation are seen. At low speeds, the couplers crush, and the cars saw-tooth buckle. At high speeds, the front end of the cab car crushes, and the cars remain in-line. If an offset load is applied, the back stairwell of the first coach car crushes unevenly, and the cars saw-tooth buckle. For the second hypothesis, the characteristics are symmetric. At low speeds, the couplers crush, and the cars remain in-line. At higher speeds, the front end crushes, and the cars remain in-line. If an offset load is applied to a car with symmetric characteristics, the cars will saw-tooth buckle.

Locomotive Crashworthiness Testing at the Transportation Technology Center

2003 ◽  
Author(s):  
Russell Walker ◽  
Gunars Spons
Keyword(s):  
Impact Test ◽  
Full Scale ◽  
Steel Coil ◽  
Technology Center ◽  
Third Phase ◽  
Wholly Owned Subsidiary ◽  
Steel Coils ◽  
Grade Crossing ◽  
Side Collision ◽  
The Right

Transportation Technology Center, Inc. (TTCI), a wholly owned subsidiary of the Association of American Railroads (AAR), has conducted three full-scale locomotive crashworthiness tests on behalf of the Federal Railroad Administration (FRA) at the FRA’s Transportation Technology Center (TTC), Pueblo Colorado. This paper describes the second and third Phase I tests. The previous test involved a locomotive striking a standing string of hopper cars. The second full-scale locomotive impact test was performed September 10, 2002. The test involved one SD-45 locomotive, modified to meet AAR Specification S-580, and three trailing loaded hopper cars impacting a stationary log truck at a grade crossing at 50.4 mph. A third full-scale impact test, conducted December 18, 2002, involved a locomotive impacting a highway truck loaded with two steel coils on a grade crossing at approximately 58 mph. The rearmost steel coil was aligned with the right side collision post of the locomotive. An anthropomorphic test device (ATD, or test dummy) was placed seated on the floor in the nose of the locomotive, facing rearward with its back against the interior door.

scholarly journals The total cavopulmonary connection resistance: a significant impact on single ventricle hemodynamics at rest and exercise

2008 ◽  
Vol 295 (6) ◽  
pp. H2427-H2435 ◽  
Author(s):  
Kartik S. Sundareswaran ◽  
Kerem Pekkan ◽  
Lakshmi P. Dasi ◽  
Kevin Whitehead ◽  
Shiva Sharma ◽  
...  
Keyword(s):  
Heart Rate ◽  
Single Ventricle ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Lumped Parameter Model ◽  
Total Cavopulmonary Connection ◽  
Dynamic Simulations ◽  
Lumped Parameter ◽  
The Impact ◽  
Cavopulmonary Connection

Little is known about the impact of the total cavopulmonary connection (TCPC) on resting and exercise hemodynamics in a single ventricle (SV) circulation. The aim of this study was to elucidate this mechanism using a lumped parameter model of the SV circulation. Pulmonary vascular resistance (1.96 ± 0.80 WU) and systemic vascular resistances (18.4 ± 7.2 WU) were obtained from catheterization data on 40 patients with a TCPC. TCPC resistances (0.39 ± 0.26 WU) were established using computational fluid dynamic simulations conducted on anatomically accurate three-dimensional models reconstructed from MRI ( n = 16). These parameters were used in a lumped parameter model of the SV circulation to investigate the impact of TCPC resistance on SV hemodynamics under resting and exercise conditions. A biventricular model was used for comparison. For a biventricular circulation, the cardiac output (CO) dependence on TCPC resistance was negligible (sensitivity = −0.064 l·min−1·WU−1) but not for the SV circulation (sensitivity = −0.88 l·min−1·WU−1). The capacity to increase CO with heart rate was also severely reduced for the SV. At a simulated heart rate of 150 beats/min, the SV patient with the highest resistance (1.08 WU) had a significantly lower increase in CO (20.5%) compared with the SV patient with the lowest resistance (50%) and normal circulation (119%). This was due to the increased afterload (+35%) and decreased preload (−12%) associated with the SV circulation. In conclusion, TCPC resistance has a significant impact on resting hemodynamics and the exercise capacity of patients with a SV physiology.

scholarly journals Dynamic characteristics of a high-speed train gearbox in the vehicle–track coupled system excited by wheel defects

2019 ◽  
Vol 234 (10) ◽  
pp. 1210-1226 ◽  
Author(s):  
Zhiwei Wang ◽  
Paul Allen ◽  
Guiming Mei ◽  
Zhonghui Yin ◽  
Yao Cheng ◽  
...  
Keyword(s):  
High Speed ◽  
Dynamic Stress ◽  
Three Dimensional ◽  
Coupled System ◽  
Transmission System ◽  
Dynamic Responses ◽  
Connected Components ◽  
Dynamics Model ◽  
High Speed Trains ◽  
Polygonal Wear

To analyse and simulate the dynamic responses of the gearbox in a vehicle–track system, a three-dimensional vehicle–track coupled dynamics model for high-speed trains has been developed in this study with a comprehensive consideration of the transmission system. Using this dynamics model, the coupling effects between the gearbox housing and its connected components were analysed. Based on the dynamic results, the dynamic stress field of the gearbox housing can be obtained using the finite element methods. The model outputs were successfully validated through comparisons with field test data. Following model validation, the dynamic stress and its distribution throughout the gearbox housing were further investigated under different excitations, including track irregularities, wheel polygonal wear and flatness. The results demonstrate a significant increase in the stress levels of the oil level window aperture and the bottom face of the housing, which coincides with the location of cracks that are formed in the gearbox housing during frequent vehicle operation. While a specific case has been studied here, the proposed dynamics model can be applied to related dynamic assessments, such as vibration or suspension parameter analyses, as well as to stress analyses of any rail vehicle transmission system to guide the maintenance and design.

A Lumped-Parameter Model for Stagnant Thermal Conductivity of Spatially Periodic Porous Media

1995 ◽  
Vol 117 (2) ◽  
pp. 264-269 ◽  
Author(s):  
C. T. Hsu ◽  
P. Cheng ◽  
K. W. Wong
Keyword(s):  
Thermal Conductivity ◽  
Numerical Solutions ◽  
Three Dimensional ◽  
Lumped Parameter Model ◽  
Circular Cylinders ◽  
Parameter Method ◽  
Two Dimensional ◽  
Algebraic Expressions ◽  
Lumped Parameter ◽  
Spatially Periodic

Based on a lumped-parameter method, algebraic expressions for the stagnant thermal conductivity of some two-dimensional and three-dimensional spatially periodic media are obtained. The geometries under consideration include arrays of touching and non-touching in-line square and circular cylinders (two-dimensional), as well as touching and nontouching in-line cubes (three-dimensional). A comparison of results based on these algebraic expressions with existing numerical solutions and experimental data shows that they are in excellent agreement.

Design, Analysis, Experimentation, and Control of a Partially Compliant Bistable Mechanism

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Ayse Tekes ◽  
Hongkuan Lin ◽  
Kevin McFall
Keyword(s):  
Dynamic Response ◽  
Elliptic Integral ◽  
Three Dimensional ◽  
Design Analysis ◽  
Lumped Parameter Model ◽  
Lumped Parameter ◽  
Rigid Body Model ◽  
3D Printed ◽  
Bistable Mechanism ◽  
And Control

Abstract This study presents the design analysis and development of a novel partially compliant bistable mechanism. Motion behavior dependence on links and relative angles are analyzed, lumped parameter model is derived, mechanism parts including the compliant members are three-dimensional (3D) printed and a state feedback controller is implemented so that the slider follows a well-defined trajectory if designed as an actuator. The proposed mechanism consists of initially straight, large deflecting fixed-pinned compliant links, rigid links, and a sliding mass. Dynamic response of the mechanism is studied using elliptic integral solutions, pseudo rigid body model (PRBM), vector closure loop equations and Elliptic integrals. Nonlinear model is simulated in matlab simulink using fourth‐order Runge‐Kutta algorithms. The research emphasizes on the realization and dynamic response of the mechanism and the trajectory control of the slider so that the slider can be kept constant at specified distances resulting a dwell motion if designed as a linear actuator.

A Three-Dimensional Lumped Parameter Model of Nanoscale Phononic Crystals

2009 ◽  
Author(s):  
Bruce L. Davis ◽  
Mahmoud I. Hussein
Keyword(s):  
Equations Of Motion ◽  
Three Dimensional ◽  
Phononic Crystals ◽  
Lumped Parameter Model ◽  
Lagrangian Equations ◽  
Area Of Interest ◽  
Simple Cubic ◽  
Lumped Parameter ◽  
Mass Spring Model ◽  
Mass Spring

This work focuses on modeling nanoscale phononic crystals by setting up the appropriate Lagrangian equations of motion. The atomic structure and force constants are accounted for by means of a lumped parameter mass-spring model. In particular we focus on a simple cubic lattice with one mass per primitive unit cell. We use the model to predict the wave propagation frequency spectrum. We then use the model to conduct a series of studies on the influence of defects intentionally introduced to the lattice at a supercell level. One area of interest is the effect of such alterations on the size and location of band gaps.

Analysis of Thermal Response of a Portable Blood Cooling Device

2009 ◽  
Author(s):  
Son H. Ho ◽  
Muhammad M. Rahman ◽  
Mutasim Elsheikh ◽  
Aydin K. Sunol
Keyword(s):  
Cooling System ◽  
Three Dimensional ◽  
Thermal Response ◽  
Biological Tissues ◽  
Lumped Parameter Model ◽  
Computational Domain ◽  
Insulation Material ◽  
Lumped Parameter ◽  
Transient Thermal ◽  
Transient Thermal Response

This paper presents the three-dimensional (3D) modeling and simulation of heat transfer within a portable blood cooling system with respect to space and time. The cooling system under study includes a cooler box with two cooling cylinders and eight blood bags. The cooler has the shape of a rectangular box with walls made of thermal-insulation material. The cooling cylinders protrude into the inner space through the bottom of the cooler box. Eight blood bags are arranged around these two cooling cylinders. The cooling cylinders use desiccant absorbing agents in combination with evaporative processes under vacuum pressure to achieve the cooling effect. Transient thermal response of the system is simulated by employing a computational approach. The computational domain includes the air inside the cooler box and the blood inside the blood bags. Heat from the surroundings penetrating the system through the insulation walls of the cooler box is included in the model. It is assumed that initially the blood is at the uniform ambient temperature. Once the cooling cylinders are activated, they draw heat from the air and the blood inside the cooler box. A lumped-parameter model is used to model the heat drawn by the cooling cylinder. The resulting solution of temperature distribution within the blood bags and the air in the cooler box is presented in the form of graphical visualization. Representative temperatures within the blood bags are presented as functions of time during a period of 12 hours. The computational model and results will be useful for the development and optimization of the design of portable cooling devices for the transportation of blood and similar biological tissues such as an organ for transplant.

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