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.