Quasi-Static and Dynamic Sled Testing of Prototype Commuter Rail Passenger Seats

Abstract

In support of the Federal Railroad Administration's (FRA) Railroad Equipment Safety Program, tests have been conducted on prototype commuter rail passenger seats which have been designed for improved occupant protection during commuter train accidents. Quasi-static tests were conducted to evaluate the moment versus rotation behavior of the seat back and to improve the fidelity of the finite element seat model. Dynamic sled tests were conducted with instrumented Hybrid III anthropomorphic test devices (ATDs) to evaluate occupant protection under collision conditions and to improve the fidelity of seat/occupant computer models.The three-passenger prototype seats were designed to meet the following dynamic test requirements:1. Seats must remain attached to the test fixture. 2. Occupants must be compartmentalized between seat rows. 3. Injury criteria for the head, chest, neck and femur must be within tolerance thresholds specified by the automotive industry. 4. All seat components, including seat cushions, must remain attached. Test conditions were specified for two dynamic sled tests as follows: three forward-facing 50 th percentile male Hybrid III ATDs subjected to an 8G, 250 millisecond triangular crash pulse; and three rear-facing 50 th percentile male Hybrid III ATDs subjected to a 12G, 250 millisecond triangular crash pulse. The 8G crash pulse is specified in the existing American Public Transportation Association (APTA) Standard for Rowto-Row Seating in Commuter Rail Cars [1] and in the Federal Code of Regulations 49 CFR 238.233 [2], and represents nominal collision conditions. The 12G crash pulse represents the collision environment measured in the cab car during a previous full-scale train-to-train impact test of passenger rail cars incorporating crash energy management [3,4].The final test results indicate that all test requirements were met: the seats remained attached to the test sled; the ATDs were compartmentalized; all the injury criteria were within accepted tolerance thresholds; and all the seat cushions remained attached.

Comparison of Interior Crashworthiness Observed in Passenger Train Accidents and 8G Dynamic Seat Sled Tests

“…In the Chatsworth accident, several passengers were likely seated in rear-facing seats, a seating configuration that has been shown to provide increased protection from secondary impacts [10]. One passenger that was interviewed after the Chatsworth accident was in a rear-facing seat on the upper level of car #617 when the accident occurred.…”

Fuel Tank Crashworthiness: Loading Scenarios

“…The results of accident investigations have helped guide research efforts to improve passenger rail equipment crashworthiness in the U.S. Such efforts include, the development of improved passenger car end frame requirements [1,2], development of crash energy management specifications for passenger trains and locomotives [3,4] and improved interior occupant features such as seats and tables [5,6].…”