Train Crashworthiness Design for Occupant Survivability

摘要

Studies were conducted evaluating the effectiveness of alternative strategies for providing crashworthiness of the vehicle structures. Conventional practice results in cars of essentially uniform longitudinal strength. The crash energy management approach requires varying strength through the train, with high strength in the occupied areas and lower strength in the unoccupied areas. For train-to-train collisions at closing speeds above 70 mph, the crash energy management approach is more effective than the conventional approach in preserving occupant volume. For closing speeds below 70 mph, both strategies are equally effective in preserving occupant volume. The crash energy management design results in gentler secondary impacts for train-to-train collisions than the conventional design, at all speeds analyzed. A method for developing the crush zone force/displacement characteristics and occupant volume strength required to limit secondary impact velocities and preserve occupant volumes is developed. Ideal force/displacement characteristics and occupant volume strength required to survive a 140 mph train-to-train collision are first determined; constraints on crush zone length and maximum occupant volume strength are then applied. The two design approaches are evaluated in terms of occupant volume lost and secondary impact injury by applying a lumped-mass model, using the parameters associated with each design, for a range of collision scenarios.