scholarly journals Two-Car Impact Test of Crash-Energy Management Passenger Rail Cars: Analysis of Occupant Protection Measurements

2004 ◽  
Author(s):  
Kristine J. Severson ◽  
Daniel P. Parent ◽  
David C. Tyrell
Keyword(s):  
Injury Risk ◽  
Impact Test ◽  
Full Scale ◽  
Rigid Barrier ◽  
Passenger Rail ◽  
Equipment Safety ◽  
Safety Research ◽  
Accident Data ◽  
Full Scale Tests ◽  
Energy Absorbing

As a part of ongoing passenger rail equipment safety research, a full-scale impact test of two cars with energy absorbing end structures was carried out on February 26, 2004. In this test, two coupled cars impacted a rigid barrier at 29 mph. Similar to previous full-scale tests in the series [1,2,3], anthropomorphic test devices (or ATDs) were included on the rail cars to measure the occupant response during the collision. These ATDs were instrumented with accelerometers and load cells to measure the injury risk to the occupants. This paper presents preliminary tests results. Five occupant experiments were included in the two-car test. Three of the experiments were similar to those conducted on the two-car test of conventional equipment that was held on April 4, 2000: forward-facing occupants in inter-city seats, forward-facing occupants in commuter seats, and rear-facing occupants in commuter seats. Two of the experiments examine the interaction of an occupant with a workstation table in a facing-seat configuration. These two tests used experimental ATDs with an increased capacity for recording abdominal impact response. To aid the analysis of this problem, MADYMO computer models were developed for four of the five of the occupant experiments. The models were either modified from earlier simulations, in the case of the commuter seats, or newly developed, in the case of the inter-city seats and table experiment with THOR ATD. The models were validated based on previous tests and/or accident data. Predictions of the ATD response agree closely for the overall kinematics of the ATDs, and for many of the measurements made with the ATDs in the full-scale test.

scholarly journals Train-to-Train Impact Test of Crash Energy Management Passenger Rail Equipment: Occupant Experiments

2006 ◽  
Author(s):  
Kristine J. Severson ◽  
Daniel P. Parent
Keyword(s):  
Energy Management ◽  
Injury Risk ◽  
Impact Test ◽  
Full Scale ◽  
Passenger Cars ◽  
Occupant Protection ◽  
Injury Threshold ◽  
Passenger Rail ◽  
Upper Abdominal ◽  
Head And Neck Injury

As part of an ongoing passenger rail crashworthiness effort, a full-scale impact test of a train with crash energy management (CEM) passenger cars was conducted on March 23, 2006. In this test, a train made up of a CEM cab car, four CEM coach cars, and a locomotive impacted a stationary train of similar mass at 30.8 mph. This test included five occupant experiments on the cab car and the first coach car to evaluate occupant injury risk and seat/table performance during the collision using anthropomorphic devices (ATDs). Three occupant protection strategies were evaluated in these occupant experiments. Forward-facing intercity seats were modified to reduce the high head injury risk observed in a previous test. Prototype commuter seats, included in both forward-facing and rear-facing orientations, were designed to mitigate the consequences of higher decelerations in the lead two CEM cars. Improved workstation tables, tested with two different advanced ATDs, were designed to compartmentalize the occupants and reduce the upper abdominal injury risk to the occupants. Similar experiments were also conducted on the two-car impact test of CEM equipment [1]. The experiments described in this paper were conducted to evaluate the level of occupant protection provided by seats and tables that were specifically designed to improve crashworthiness. Pre-test analyses indicated that the occupant environment would be more severe for the CEM test than for the comparable test of conventional equipment. The environment in the leading cab car was predicted to be similar to a 12g, 250 millisecond triangular crash pulse. The environment in the first coach was predicted to be comparable to an 8g, 250 millisecond crash pulse. To aid the design of the occupant experiments, occupant response models were developed for each of the occupant experiments using MADYMO. These models were developed for the previous two-car CEM full-scale test and adapted to the newly designed commuter seats and tables. Predictions of the occupant response during the CEM train-to-train test were developed before the test. The models were subsequently fine-tuned to better agree with the test data, so that many different collision scenarios may be simulated. Most of the test results were similar to the pre-test predictions. The modified intercity seats successfully compartmentalized the occupants. The risk of both head and neck injury, however, were above the respective injury threshold values. In the forward-facing commuter seat experiment the impacted seat experienced a partial failure of the seat pedestal attachment, resulting in loss of compartmentalization. The attachment failures occurred because the seats weren't fabricated as designed. However, the occupants were still compartmentalized, and the injury criteria were within survivable levels. The rear-facing commuter seat experiment experienced a more significant failure of the seat pedestal attachment, resulting in a loss of compartmentalization. The attachment failures likely occurred because the seats were not fabricated as designed and the collision was slightly more severe than predicted. To assure that this failure mode is prevented in the future, a more robust attachment is currently being developed. It will be tested quasi-statically and dynamically to demonstrate its effectiveness. The improved workstation tables successfully compartmentalized the occupants while limiting the injury risk to acceptable levels.

Component and Full Scale Tests for Suspension Model Validation

2009 ◽  
Author(s):  
Pradeep Mohan ◽  
Dhafer Marzougui ◽  
Cing-Dao Kan ◽  
Kenneth Opiela
Keyword(s):  
Full Scale ◽  
Transportation Safety ◽  
Fe Model ◽  
George Washington ◽  
Model Library ◽  
Safety Research ◽  
Oblique Impacts ◽  
Full Scale Tests ◽  
Suspension Model ◽  
Roadside Hardware

The National Crash Analysis Center (NCAC) at the George Washington University (GWU) has been developing and maintaining a public domain library of LS-DYNA finite element (FE) vehicle models for use in transportation safety research. The recent addition to the FE model library is the 2007 Chevrolet Silverado FE model. This FE model will be extensively used in roadside hardware safety research. The representation of the suspension components and its response in oblique impacts into roadside hardware are critical factors influencing the predictive capability of the FE model. To improve the FE model fidelity and applicability to the roadside hardware impact scenarios it is important to validate and verify the model to multitude of component and full scale tests. This paper provides detailed description of the various component and full scale tests that were performed, specifically, to validate the suspension model of the 2007 Chevrolet Silverado FE model.

Effect of Light Poles on Vehicle Impacts with Roadside Barriers

1997 ◽  
Vol 1599 (1) ◽  
pp. 32-39 ◽  
Author(s):  
James C. Kennedy
Keyword(s):  
Full Scale ◽  
Lack Of Information ◽  
Large Numbers ◽  
Highway Network ◽  
Accident Data ◽  
Full Scale Tests ◽  
Light Pole ◽  
National Cooperative ◽  
The Impact ◽  
Crash Tests

Light poles installed within the deflection zone of roadside barriers (guardrails) may influence the ability of the guardrail to safely redirect an impacting vehicle. One concern is that, during an impact, the vehicle may pivot about the relatively rigid light pole and then spin away from the guardrail back into the traffic stream in an uncontrolled, unsafe manner. A large percentage of the highway network in Ohio uses the type of guardrail and light pole configurations, in which the breakaway light poles are placed at either 15.2- or 45.7-cm (6- or 18-in.) lateral distance from the back of the guardrail, depending on one of two light pole base designs in use. These pole-guardrail systems were placed in large numbers some years ago and Ohio accident data have been inadequate to provide information to determine whether or not a problem exists with this system. Proposed highway rehabilitation and reconstruction projects can include changes or adjustments to placement of guardrails and light poles, but there was a lack of information as to whether or not the past practices possessed a problem. A study was conducted to determine if light poles have an adverse effect on the redirecting performance of guardrails. It included six full-scale crash tests involving two vehicle weight classes (2000P and 820C), two light pole base designs (AT-A and AT-X), and a typical guardrail used in Ohio [Type 5 (W-Beam)]. All full-scale tests were carried out according to the recommended procedures in National Cooperative Highway Research Program (NCHRP) Report 350. The actual vehicles used for the 2000P class were half-ton pickup trucks ballasted to simulate the weight and mass characteristics of the 2000P vehicle that is specified in NCHRP Report 350. The guardrail–light pole system was not shown to cause snagging or subsequent unstable motion of the vehicle due to impact. All vehicles exited the guardrail in a stable manner. No change in the arrangement of light poles behind the Type 5 guardrail is contemplated. The redirecting function of the guardrail was not compromised as a result of placement of the light pole behind the length-of-need. Excessive exit angle situations (according to NCHRP Report 350) occurred in three tests involving the simulated 2000P class vehicles. However, the impact conditions employed for these tests were extreme, and the likelihood of this situation occurring under everyday highway usage may be small.

scholarly journals Development of Crash Energy Management Designs for Existing Passenger Rail Vehicles

2004 ◽  
Author(s):  
Eloy Martinez ◽  
David Tyrell ◽  
Benjamin Perlman
Keyword(s):  
Energy Management ◽  
Full Scale ◽  
Lateral Buckling ◽  
Passenger Rail ◽  
Rail Vehicles ◽  
Used Car ◽  
Baseline Levels ◽  
Full Scale Tests ◽  
Prototype Design ◽  
Crush Zone

As part of the passenger equipment crashworthiness research, sponsored by the Federal Railroad Administration and supported by the Volpe Center, passenger coach and cab cars have been tested in inline collision conditions. The purpose of these tests was to establish baseline levels of crashworthiness performance for the conventional equipment and demonstrate the minimum achievable levels of enhancement using performance based alternatives. The alternative strategy pursued is the application of the crash energy management design philosophy. The goal is to provide a survivable volume where no intrusion occurs so that passengers can safely ride out the collision or derailment. In addition, lateral buckling and override modes of deformation are prevented from occurring. This behavior is contrasted with that observed from both full scale tests recently conducted and historical accidents where both lateral buckling and/or override occurs for conventionally designed equipment. A prototype crash energy management coach car design has been developed and successfully tested in two full-scale tests. The design showed significant improvements over the conventional equipment similarly tested. The prototype design had to meet several key requirements including: it had to fit within the same operational volume of a conventional car, it had to be retrofitted onto a previously used car, and it had to be able to absorb a prescribed amount of energy within a maximum allowable crush distance. To achieve the last requirement, the shape of the force crush characteristic had to have tiered force plateaus over prescribed crush distances to allow for crush to be passed back from one crush zone to another. The distribution of crush along the consist length allows for significantly higher controlled energy absorption which results in higher safe closing speeds.

scholarly journals Design of a Workstation Table With Improved Crashworthiness Performance

2005 ◽  
Author(s):  
Daniel P. Parent ◽  
David C. Tyrell ◽  
Robert Rancatore ◽  
Benjamin Perlman
Keyword(s):  
Injury Risk ◽  
Federal Regulations ◽  
Construction Costs ◽  
Occupant Protection ◽  
Design Concepts ◽  
Passenger Rail ◽  
Risk Of Injury ◽  
Material Usage ◽  
Design Requirements ◽  
Energy Absorbing

Work is currently underway to develop strategies to protect rail passengers seated at workstation tables during a collision or derailment. Investigations have shown that during a collision, these tables can present a hostile secondary impact environment to the occupants. This effort includes the design, fabrication, and testing of an improved workstation table. The key criteria for the design of this table are that it must compartmentalize the occupants and reduce the risk of injury relative to currently installed tables. Strengthening the attachments between the table and the passenger car body will ensure compartmentalization. Employing energy-absorbing mechanisms to limit and distribute the load imparted on the abdomen of the occupant will reduce injury risk. This paper details the design requirements for an improved workstation table, which include service, fabrication, and occupant protection requirements. Service requirements define the geometry of the table, the performance of the table under normal service loads, and the maintenance of the table over the period of installation. Fabrication requirements define the limitations on material usage and construction costs. Occupant protection requirements define the ability of the table to reduce injury risk to the occupants under collision loads. The table must also conform to federal regulations pertaining to interior structures on passenger rail equipment. Four design concepts are evaluated against these design requirements. These concepts present different modes of deformation or displacement that absorb energy during impact. These concepts have been evaluated, and the highest-ranking concept involves a crushable foam or honeycomb table edge attached to a rigid center frame. Preliminary results from a computer simulation demonstrate the effectiveness of this concept in reducing the injury risk to the occupants.

scholarly journals Analysis of Colliding Vehicle Interactions for the Passenger Rail Train-to-Train Impact Test

Joint Rail ◽  
2004 ◽  
Author(s):  
Richard Stringfellow ◽  
Robert Rancatore ◽  
Patricia Llana ◽  
Ronald Mayville
Keyword(s):  
Finite Element ◽  
Test Data ◽  
Impact Test ◽  
Full Scale ◽  
Passenger Train ◽  
Passenger Rail ◽  
Model Predictions

A full-scale train-to-train impact test was performed in which a cab car-led passenger train traveling at 30 mph collided with a standing locomotive-led train. During the test, the lead cab car overrode the cab of the standing locomotive, sustaining approximately 20 feet of crush, while the cab of the locomotive remained essentially intact. In this study, a finite element-based analysis of the collision was performed. The first 0.5 seconds of the collision was simulated. Results of the analysis were compared with accelerometer and video test data. Specific comparisons are made between test data and model predictions for: motions of the cab car and the standing locomotive; longitudinal forces arising between the cab car and the standing locomotive and between the respective lead and trailing vehicles; and the mode of deformation of the cab car and the locomotive. The results of the study indicate that the model captures pertinent features of the first 0.3 seconds of the collision, particularly with respect to longitudinal vehicle motions and collision forces. After 0.3 seconds, agreement between model predictions and test data becomes progressively worse. This is attributable to the model’s inability to capture the massive fracture that occurs at the front of the cab car.

Investigation of planing craft maneuverability using full-scale tests

2021 ◽  
pp. 147509022110303
Author(s):  
Kazem Sadati ◽  
Hamid Zeraatgar ◽  
Aliasghar Moghaddas
Keyword(s):  
Full Scale ◽  
Performance Characteristics ◽  
Forward Speed ◽  
Speed Reduction ◽  
Planing Craft ◽  
Full Scale Tests ◽  
Turning Maneuver

Maneuverability of planing craft is a complicated hydrodynamic subject that needs more studies to comprehend its characteristics. Planing craft drivers follow a common practice for maneuver of the craft that is fundamentally different from ship’s standards. In situ full-scale tests are normally necessary to understand the maneuverability characteristics of planing craft. In this paper, a study has been conducted to illustrate maneuverability characteristics of planing craft by full-scale tests. Accelerating and turning maneuver tests are conducted on two cases at different forward speeds and rudder angles. In each test, dynamic trim, trajectory, speed, roll of the craft are recorded. The tests are performed in planing mode, semi-planing mode, and transition between planing mode to semi-planing mode to study the effects of the craft forward speed and consequently running attitude on the maneuverability. Analysis of the data reveals that the Steady Turning Diameter (STD) of the planing craft may be as large as 40 L, while it rarely goes beyond 5 L for ships. Results also show that a turning maneuver starting at planing mode might end in semi-planing mode. This transition can remarkably improve the performance characteristics of the planing craft’s maneuverability. Therefore, an alternative practice is proposed instead of the classic turning maneuver. In this practice, the craft traveling in the planing mode is transitioned to the semi-planing mode by forward speed reduction first, and then the turning maneuver is executed.

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