Investigation and simulation of lateral buckling in trains

2011 Joint Rail Conference

2011

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.

Section: Discussion and Next Stepsmentioning

confidence: 99%

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

Llana

2011 Joint Rail Conference

2011

“…There are typically gaps and uncertainties in the information available from accidents. Analyses and tests are used to fill in the gaps of information available from accidents (6,7,8,9,10,11). Analytic models and tests, similar to those developed and conducted for the conventional equipment, are used to evaluate the effectiveness of the alternative designs (6,8,12,13,14).…”

Section: Researchmentioning

confidence: 99%

“…The lateral and vertical forces can amplify any tendency toward lateral buckling of the train or toward override. Figure 4 shows the force/crush characteristics developed from measurements made during impact tests of a single passenger car into a fixed barrier and of two coupled passenger cars into a fixed barrier (7,8,9). Both of these curves have high initial peak loads followed by significantly lower loads, which are approximately constant, for continued crush.…”

Section: Lateral Componentmentioning

confidence: 99%

Rail passenger equipment accidents and the evaluation of crashworthiness strategies

Proceedings of the Institution of Mechanical Engineers, Part F:

2002

The U.S. Department of Transportation's Federal Railroad Administration's (FRA) Office of Research and Development has been conducting research into rail equipment crashworthiness. The approach taken in conducting this research has been to review relevant accidents, identify options for design modifications to improve occupant survivability, and to apply analytic tools and testing techniques for evaluating the effectiveness of these strategies. Accidents have been grouped into three categories: train-to-train collisions, collisions with objects, such as grade crossing collisions, and derailments and other single train events. In order to determine the potential effectiveness of improved crashworthiness equipment, computer models have been used to simulate the behavior of conventional and modified equipment in scenarios based on accidents. INTRODUCTIONTrain accidents can be tragic events, with loss of life and serious injuries. The crashworthiness features of the train are intended to minimize fatalities and injuries if an accident does occur. The purpose of such features is to preserve sufficient space for the occupants to ride out the collision, and to maintain the forces and decelerations imparted to the occupants within survivable levels. Structural features of the cars, such as longitudinal strength of the carbody and crush zones at the ends of cars, influence how well the cars preserve the occupant volume during a collision and the decelerations imparted to the occupants. Occupant protection features inside the car, such as compartmentalization, influence the forces imparted to the occupants.

“…Sawtooth buckling, large-displacement buckling, and side-to-side impacts due to large-displacement buckling have been observed in accidents [27,28]. The progression of the cars from inline, to the sawtooth lateral buckling pattern, then to the large amplitude pattern has been simulated [4] with computational models.…”

Section: Force (Kips)mentioning

confidence: 99%

“…As part of this research, computer models have been developed and applied to determine the response of rail equipment in a range of collision scenarios [1,2,3,4,5,6]. In-line and oblique train-to-train collisions, as well as grade crossing collisions and rollover events subsequent to derailment have been modeled.…”

Section: Introductionmentioning

confidence: 99%

Train-to-Train Impact Test: Analysis of Structural Measurements

Severson

Perlman

et al. 2002

Rail Transportation

This paper describes the results of the train-to-train impact test conducted at the Transportation Technology Center in Pueblo, Colorado on January 31, 2002. In this test, a cab car-led train, initially moving at 30 mph, collided with a standing locomotive-led train. The initially moving train included a cab car, three coach cars, and a trailing locomotive, while the initially standing train included a locomotive and two open-top hopper cars. The hopper cars were ballasted with earth such that the two trains weighed the same, approximately 635 kips each. The cars were instrumented with strain gauges, accelerometers, and string potentiometers, to measure the deformation of critical structural elements, the longitudinal, vertical, and lateral car body accelerations, and the displacements of the truck suspensions. The test included test dummies in the operator's seat of the impacted locomotive, in forward-facing conventional commuter passenger seats in the cab car and first coach car, and in intercity passenger seats modified with lap and shoulder belts in the first coach car.During the train-to-train test, the cab car overrode the locomotive; the underframe of the cab car sustained approximately 22 feet of crush and the first three coupled connections sawtooth buckled. The short hood of the locomotive remained essentially intact, while there was approximately 12 inches of crush of the windshield center post. There was nearly no damage to the other equipment used in the test. The measured response of the trains compare closely with predictions made with simulation models.