Deformability and Energy Absorption for Optimized End Frame Designs for Passenger Rail Cars

011585322006PDFTech ReportRR06-15CrashworthinessEnergy absorptionModulus of deformationPassenger carsVehicle designVehicle framesRailroadsSafety and Human FactorsVehicles and EquipmentI91: Vehicle Design and SafetyUnited StatesUnited States. Federal Railroad AdministrationMartinez, EloyUnited States. Federal Railroad AdministrationUS Transportation CollectionAt the request of the American Public Transportation Association (APTA), the Office of Research and Development of the Federal Railroad Administration (FRA) sponsored a research initiative to clarify the definition of acceptable large deformations for end frame structural members. This request was prompted by discussions between two operating authorities currently evaluating a newly designed cab car for compliance with the requirements stipulated in the APTA-C&S-S034-99 standard for the design of passenger rail rolling stock and a car manufacturer directed to test the new cab car design. Within the then accepted standard was language requiring the end frame members of a car to maintain connection strength even when experiencing \u201csevere deformations.\u201d The operating authorities and the car manufacturer could not agree on whether or not the quasi-static large deformation tests demonstrated the compliance of the design. This research study addressed the issue raised by comparing the Bombardier\u2019s M7 cab car design with the FRA sponsored state-of-the-art (SOA) end frame design. The SOA design deformed gracefully for large crush distances without experiencing failure at attachment points during the full-scale grade crossing test conducted on June 7, 2002, at the Transportation Technology Center. Models of both the M7 and the SOA end frames were subjected to quasi-static and dynamic loading conditions. Figure 1 shows a comparison of the deformations from the quasi-static testing of the M7 end frame with models where excellent agreement was demonstrated. The results presented served as the technical basis for developing revised language for incorporation into the APTA-C&S-S034 industry standard adopted in 2005 for deformability and energy absorption of end frame members, as well as proposed language for a dynamic performance standard for possible rule text promulgation.78