Impact Tests of Crash Energy Management Passenger Rail Cars: Analysis and Structural Measurements

Abstract

Two full-scale impact tests were conducted to measure the crashworthiness performance of Crash Energy Management (CEM) passenger rail cars. On December 3, 2003 a single car impacted a fixed barrier at approximately 35 mph and on February 26, 2004, two-coupled passenger cars impacted a fixed barrier at approximately 29 mph. Coach cars retrofitted with CEM end structures, which are designed to crush in a controlled manner were used in the test. These test vehicles were instrumented with accelerometers, string potentiometers, and strain gages to measure the gross motions of each car body in three dimensions, the deformation of specific structural components, and the force-crush characteristic of the CEM end structure. Collision dynamics models were developed to predict the gross motions of the test vehicle. Crush estimates as a function of test speed were used to guide test conditions. This paper describes the results of the CEM single-car and two-car tests and provides results of the structural test. The single-car test demonstrated that the CEM design successfully prevented intrusion into the occupied volume, under similar conditions as the conventional test. During both CEM tests, the leading passenger car crushed approximately three feet, preserving the occupant compartment. In the two-car test, energy dissipation was transferred to the coupled interface, with crush totaling two feet between the two CEM end structures. The pushback of the couplers kept the cars in-line, limiting the vertical and lateral accelerations. In both the conventional tests there was intrusion into the occupant compartment. In the conventional two-car test sawtooth lateral buckling occurred at the coupled connection. Overall, the test results and model show close agreement of the gross motions. The measurements made from both tests demonstrate that the CEM design has improved crashworthiness performance over the conventional design.