Analysis of Collision Safety Associated With Conventional and Crash Energy Management Cars Mixed Within a Consist

2003 ◽  
Author(s):  
Kristine J. Severson ◽  
David C. Tyrell ◽  
A. Benjamin Perlman
Keyword(s):  
Energy Absorption ◽  
Energy Management ◽  
Significant Benefit ◽  
Collision Dynamics ◽  
Dynamics Model ◽  
Safety Hazards ◽  
Passenger Train ◽  
Occupant Protection ◽  
Potential Safety ◽  
Collision Safety

A collision dynamics model of a passenger train-to-passenger train collision has been developed to simulate the potential safety hazards and benefits associated with mixing conventional and crash energy management (CEM) cars within a consist. This paper presents a comparison of estimated injuries and fatalities for seven collision scenarios based upon the variable mix of conventional and CEM cars. Based on the analysis results, recommended car placement when mixing cars within a consist is identified. The model includes a 6 car cab car-led consist colliding with a 6 car locomotive-led stationary consist. The stationary consist is made up of all conventional cars. The moving consist has a variable mix of conventional and CEM cars. For comparison, the bounding scenarios are: - a moving consist with all conventional cars, and - a moving consist with all CEM cars. The collision speed ranges from 15 to 35 mph. Since the two car designs behave differently under impact conditions, there is a concern that there may be hazards associated with mixing the two designs in the same consist. In none of the cases evaluated is the mixed consist less crashworthy than the conventional consist. The modeling results indicate that the least crashworthy consists are ones in which a conventional cab car is leading any combination of vehicles. The conventional cab car incurs nearly all the damage and prevents trailing cars from participating in energy absorption, whether they are conventional or CEM. The most crashworthy consists are ones in which a CEM cab is leading. The CEM cab can absorb a significant amount of energy without intruding into the occupied volume. The CEM cab also allows trailing cars to participate in energy absorption, which provides further occupant protection. The recommended strategy for car placement is to put the CEM car(s) at the leading end(s) and the conventional car(s) at the trailing end or in the middle of the consist in push-pull operation. There is also significant benefit to placing the seats in the leading CEM car or two so they are rear-facing. Rear-facing seats can reduce the severity of secondary impact injuries because the occupant is already in contact with the seat in the direction of travel and does not develop a significant velocity relative to the seat.

scholarly journals Energy absorption design study of subway vehicles based on a scaled equivalent model test

2018 ◽  
Vol 233 (1) ◽  
pp. 3-15 ◽  
Author(s):  
Ping Xu ◽  
Sisi Lu ◽  
Kaibo Yan ◽  
Shuguang Yao
Keyword(s):  
Energy Absorption ◽  
Model Test ◽  
Equivalent Model ◽  
Scale Model ◽  
Crash Test ◽  
Collision Dynamics ◽  
Dynamics Model ◽  
Three Dimensional Model ◽  
Scaled Model ◽  
Simulation Results

To obtain the characteristics of collision energy absorption and improve the passive safety of subway vehicles, the energy absorption design of subway vehicles was studied based on a one-seventh-scale model crash test. A full-size three-dimensional model of a subway vehicle was established using the multibody dynamics software MADYMO. The simulation results of the dynamics model were scaled down according to the similarity coefficients. By comparing the simulation results with the scaled model test results, the maximum error of deformation was 2.10 and 4.35% for the head car and the maximum deforming middle car, respectively, and the energy absorption error was found to be 8.75 and 5.70% for the head car and the maximum deforming middle car, respectively. The results indicate that the collision dynamics model of subway vehicles is relatively accurate. Next, based on this dynamics model, a full factorial experiment was designed to study the effects of the marshalling, mass and crushing tube’s plastic deformation platform force on the energy absorption of subway vehicles. The calculation results were fitted by multiple linear regression functions. Finally, the authors obtained the crash energy absorption formulas for the subway head car with an accuracy of 98.42% and for the maximum deforming middle car with an accuracy of 95.31%. These formulas can be applied to the preliminary design of subway vehicles and offer guiding significance for the parameter design of subway vehicles’ energy-absorbing devices.

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.

COLLISION DYNAMICS OF X@C60(X = He, Ne, Ar) AT LOW ENERGIES

2013 ◽  
Vol 27 (30) ◽  
pp. 1350225
Author(s):  
QIANG ZHAO ◽  
FENG-SHOU ZHANG ◽  
HONG-YU ZHOU
Keyword(s):  
Self Assembly ◽  
Collision Dynamics ◽  
Dynamics Model ◽  
Great Role ◽  
Energy Effect ◽  
Endohedral Fullerenes ◽  
Central Collisions ◽  
Low Energies ◽  
Fullerene Dimers ◽  
Semi Empirical

In this paper, a semi-empirical molecular dynamics model is developed. The central collisions of C 60 + C 60 and X@C 60 + X@C 60 ( X = He , Ne , Ar ) at various incident energy are investigated within this model. The fullerene dimers like a "dumbbell" can be formed by a self-assembly of C 60 fullerene and X@C 60 ( X = He , Ne ) endohedral fullerenes, and the new fullerene structure like "peanut" can be formed by a self-assembly of Ar@C 60. It is found that Ar atom plays a great role in the collision of Ar@C 60 + Ar@C 60 because of its size effect. The energy effect is found that various incident energies cannot change the final structure at low energies if they are below a certain energy.

Study on Food Safety and Green Food Packaging

2012 ◽  
Vol 550-553 ◽  
pp. 1915-1918
Author(s):  
Lin Lin Shang ◽  
Wei Feng
Keyword(s):  
Food Safety ◽  
Human Health ◽  
Food Packaging ◽  
Packaging Materials ◽  
Safety Hazards ◽  
Safety Problem ◽  
Green Food ◽  
Potential Safety ◽  
Safe Food

Safe food packaging is of great significance in solving food safety problem, which can ensure the quality of the food. At the same time protecting the environment should be taken into consideration, and therefore sound food packaging is not only safe to human health but also green to the environment. In this paper potential safety hazards in food packaging materials and how to develop green food packaging are discussed at length.

scholarly journals Recent Progress on Catalysts for the Positive Electrode of Aprotic Lithium-Oxygen Batteries †

Inorganics ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 69 ◽  
Author(s):  
Yichao Cai ◽  
Yunpeng Hou ◽  
Yong Lu ◽  
Jun Chen
Keyword(s):  
High Performance ◽  
Noble Metals ◽  
Catalytic Mechanism ◽  
Low Cost ◽  
Rate Capability ◽  
Positive Electrode ◽  
Safety Hazards ◽  
Environmental Friendliness ◽  
Potential Safety ◽  
Lithium Oxygen Batteries

Rechargeable aprotic lithium-oxygen (Li-O2) batteries have attracted significant interest in recent years owing to their ultrahigh theoretical capacity, low cost, and environmental friendliness. However, the further development of Li-O2 batteries is hindered by some ineluctable issues, such as severe parasitic reactions, low energy efficiency, poor rate capability, short cycling life and potential safety hazards, which mainly stem from the high charging overpotential in the positive electrode side. Thus, it is of great significance to develop high-performance catalysts for the positive electrode in order to address these issues and to boost the commercialization of Li-O2 batteries. In this review, three main categories of catalyst for the positive electrode of Li-O2 batteries, including carbon materials, noble metals and their oxides, and transition metals and their oxides, are systematically summarized and discussed. We not only focus on the electrochemical performance of batteries, but also pay more attention to understanding the catalytic mechanism of these catalysts for the positive electrode. In closing, opportunities for the design of better catalysts for the positive electrode of high-performance Li-O2 batteries are discussed.

Evaluation of Rail Passenger Equipment Crashworthiness Strategies

2003 ◽  
Vol 1825 (1) ◽  
pp. 8-14 ◽  
Author(s):  
David Tyrell ◽  
A. Benjamin Perlman
Keyword(s):  
Energy Management ◽  
Maximum Speed ◽  
Passenger Train ◽  
Grade Crossing

Comparisons are made of the effectiveness of competing crashworthiness strategies—crash energy management (CEM) and conventional passenger train design. CEM is a strategy for providing rail equipment crashworthiness that uses crush zones at the ends of cars. These zones are designed to collapse in a controlled way during a collision, distributing the crush among the train cars. This technique preserves the occupied spaces in the train and limits the decelerations of the occupant volumes. Two scenarios are used to evaluate the effectiveness of the crashworthiness strategies—( a) a train-to-train collision of a cab-car–led passenger train with a standing locomotive–led passenger train and ( b) a grade-crossing collision of a cab-car-led passenger train with a standing highway vehicle. The maximum speed for which all the occupants are expected to survive and the predicted increase in fatalities and injuries with increasing collision speed are determined for both train designs. Crash energy management is shown to significantly increase the maximum speed at which all the occupants could survive for both grade crossing and train-to-train collisions for cab-car–led trains, at the expense of modestly increasing the speeds at which occupants impact the interior in train-to-train collisions.

scholarly journals Computer Big Data Technology in Internet Network Communication Video Monitoring of Coal Preparation Plant

2021 ◽  
Vol 2083 (4) ◽  
pp. 042067
Author(s):  
Hao Chen ◽  
XinLi Zi ◽  
Qing Zhang ◽  
YuGe Zhu ◽  
JiaYin Wang
Keyword(s):  
Big Data ◽  
Monitoring System ◽  
Video Monitoring ◽  
Coal Preparation ◽  
Centralized Control ◽  
Safety Hazards ◽  
Fully Integrated ◽  
Potential Safety ◽  
Preparation Plant ◽  
Big Data Technology

Abstract The paper uses the control technology of computer big data and PLC, fieldbus communication technology and video monitoring technology to research, design and develop the monitoring system of the coal preparation plant’s production process. In this plan, the coal preparation plant’s video monitoring system, production centralized control system and other production support systems are fully integrated through network technology, to achieve the purpose of improving its safety guarantee function. The system improves the level of visual management, realizes unattended operation, and reduces potential safety hazards.

scholarly journals Preliminary Reconstruction of the November 30, 2007, Chicago, IL Rail Collision

2011 ◽  
Author(s):  
Patricia Llana ◽  
David Tyrell
Keyword(s):  
Field Study ◽  
Preliminary Data ◽  
Structural Damage ◽  
Passenger Train ◽  
Occupant Protection ◽  
Causal Mechanisms ◽  
Occupant Injuries ◽  
The Impact

The Volpe Center is supporting the Federal Railroad Administration in performing rail passenger equipment crashworthiness research. The overall objective of this research is to develop strategies for improving structural crashworthiness and occupant protection. A field study of passenger train accidents is being conducted to investigate the causal mechanisms of the injuries incurred by train occupants. The investigation of the November 30, 2007 collision in Chicago, IL has provided preliminary data on the structural damage as well as occupant injuries resulting from the impact. This data will be used in simulations to guide the development of crashworthiness strategies.

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.

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