Evaluation of Occupant Volume Strength in Conventional Passenger Railroad Equipment

To ensure a level of occupant volume protection, passenger railway equipment operating on mainline railroads in the United States must be designed to resist an 800,000-lb compressive load applied statically along the line of draft. An alternative manner of evaluating the strength of the occupied volume is sought, which will ensure the same level of protection for occupants of the equipment as the current test, but will allow for a greater variety of equipment to be evaluated. A finite element (FE) model of the structural components of a railcar has been applied to examine the existing compressive strength test and evaluate selected alternate testing scenarios. Using simplified geometric and material properties, a generic single-level railcar model was constructed that captured the gross behaviors of the railcar without excessive processing time. When loaded, the carbody structure exhibits some single beam-like behaviors. Application of the existing 800 kip compressive load results in a significant bending moment as well as significant compressive forces. The alternative load cases examined show that a larger total compressive force may be distributed across the end structure of the railcar and result in similar stress levels throughout the structural frame as observed from application of the conventional proof load.