The energy distribution of a train impact process based on the active-passive energy-absorption method

Abstract

This paper examines the energy-absorption characteristics of trains for active-passive safety protection. A one-dimensional collision-simulation model of traditional subway vehicles and active-passive safety vehicles was developed based on the multibody dynamics theory using MATLAB simulation software. The effectiveness of the simulation model was verified by scaled-collision tests. Then, the energy-absorption characteristics of traditional trains and the active-passive safety trains under different marshalling conditions were studied. The results showed that as the number of marshalling vehicles increased from 5 to 8, the energy absorption of interface 1 for the active-passive safety trains during the collision was 681 kJ, 775 kJ, 840 kJ and 901 kJ, and the physical compression of the interface of the head car of the active-passive safety trains was 619 mm, 704 mm, 764 mm and 816 mm, which was far below the maximum value of 1773 mm. The head car of the active-passive safety subway vehicles therefore had sufficient energy-absorption capacity. Finally, to find the maximum safe impact velocity of the active-passive safety trains, the energy distribution of the active-passive safety subway vehicles with 8-car marshalling at different impact velocities was studied. It was found that the safe impact velocity of an active-passive safety subway vehicle conforming to the requirements of the EN15227 collision standard reached 32 km/h, far exceeding the safe impact velocity of 25 km/h allowed by traditional trains, and representing an increase in the safe impact velocity of 28%. The total collision-energy absorption of the interface of the head car of the active-passive trains was 89.1% higher than that of the traditional trains at the safe impact velocity. The active-passive energy absorption method was therefore effective at improving the crashworthiness of the subway trains.