Evaluation Method for Crashworthiness Using Integrated Value of Deceleration of Railway Vehicles Showing High Correlation with Degree of Passenger Injury

Abstract

While standards for crashworthiness of railway vehicles have been defined in Europe and the U.S., there is no standard in Japan. Therefore, it is important to establish an evaluation method for crashworthiness of railway vehicles in Japan. The authors carried out finite element analyses under various conditions based on the statistical analysis of serious level-crossing accidents. We evaluated the mean decelerations (con-forming to European standard), the maximum decelerations (U.S. standard) and integrated values of the deceleration, which are obtained from impact deceleration waveforms in the passenger area. We also performed finite element analyses of dummy’s behavior and injury values using these deceleration waveforms as input. We examined the correlation between these evaluation results and dummy’s injury values. As a result, we confirmed that the integrated values of the deceleration of the passenger area had the highest correlation with the dummy’s injury values. the estimated collision speed, with the whole divided into two categories according to the mass of each collision obstacle. Compact cars, light trucks, and tractors were classified as relatively lightweight obstacles, and trucks, trailers, dump-trucks, and buses were classified as relatively heavy obstacles. The approx imate estimated collision speed was calculated by using the distance from the brake start point of the train to the level-crossing and the train speed at the start of braking (based on the crew’s verbal report), and by assuming that the deceleration was constant. The Railway Safety Database of Railway Technology Promotion Center at the RTRI was used for the general condition survey of each accident, of Earth retaining structures, such as bridge abutments and retaining walls, are constructed at the boundary of bridges or embankments. There are a variety of earth retaining structure failure modes, therefore in order to be able to ensure rational aseismic reinforcement, it is necessary to develop a range of different aseismic reinforcement methods adapted to the relevant earth retaining structure’s failure mode. Moreover, there are many cases where construction work is severely restricted due to various limitations, such as land boundaries, available space, and time available for construction work. Therefore, the authors propose an aseismic reinforcement method, which can both improve seismic performance of earth retaining structures and be carried out efficiently. This paper outlines this research and describes some examples of the practical application of the newly developed reinforcement method.