Passenger Car Crippling End-Load Test and Analyses
The Transportation Technology Center, Inc. (TTCI) performed a series of full-scale tests and a finite element analysis (FEA) in a case study that may become a model for manufacturers seeking to use the waiver process of Tier I crashworthiness and occupant protection standards to qualify railcars with alternative designs. The test series included an 800,000-lb quasi-static compressive end-load applied through floor-level crash energy management (CEM) pockets and a crippling compressive load applied through the floor and roof level CEM pockets. Although the first test did not strictly meet the 49 Code of Federal Regulations (CFR) § 238.203, it demonstrated that the passenger railcar can withstand the compressive load along the line of draft. In collaboration with TTCI, Arup North America developed a detailed finite element (FE) model that was calibrated with the linear test results and then used the model to predict the results of the crippling load test. The Volpe National Transportation Systems Center (Volpe) performed an independent FEA of the same test car in parallel to Arup’s analysis using different FE software and modeling techniques. The results from the crippling load test showed that the final crippling load was approximately 1,100,000 pounds and the reduction in car length was approximately 3 inches.