Study of occupant safety evaluation for collision accident of railway vehicle (Investigation of relation between deceleration during collision and injury parameters)

Abstract

The maximum deceleration or average deceleration during the collision is used to assess occupant safety in regards to the crashworthiness design of railway vehicles. However, the deceleration history experienced by the passengers during the collision is not always the same as the deceleration history of car body because the passengers are not restrained by seatbelts. Secondary impact of passenger to a partition panel at end saloon in different deceleration histories was investigated by calculations using a numerical simulation model of the Hybrid Ⅲ 50 percentile dummy that is built into the LS-DYNA computer program. In order to validate the calculation model, a sled test to simulate a secondary impact at the end saloon was conducted. It was found that there is correlation between the maximum of integration of deceleration history(MID) and secondary impact velocity(SIV) of the crash dummy and there are relations between SIV and injury parameters such as HIC15 and femur load specified in 49 CFR571. 208 Passenger Equipment Safety Standards. More specifically, the calculation results showed that the SIV of the head and the SIV of the knee are represented by the MID + 1m/s and the MID -1m/s respectively for conservative evaluation at the end saloon of express trains in Japan. In addition, calculation results showed that the upper limit of the SIV to partition panels for HIC15 and femur load within their criteria is 6m/s. As a consequence, it is thought when the MID is lower than 5m/s, HIC15 and femur load is lower than their criteria for conservative evaluation at the end saloon of express trains in Japan.