Simulation of Airbag Ejection Acceleration Process on a Train Collision Testbed

To solve the driving problem with great energy for a train collision testbed, the airbag with a self-growth variable boundary was proposed. The airbag with high-pressure gas can work effectively in a long distance under the condition of constraint and un-blasting. Based on the control volume method, an ejection model of the circlewise folding airbag was built using the simulation software LS-PrePost and LS-DYNA. The influence of the ejection process and structural features of multilevel airbags on the ejection behavior and energy was studied under conditions of initial compression and a certain pressure, respectively. The results show that the ejection model of the circlewise folding airbag can reflect the basic characteristics of the airbag ejection acceleration method, and the airbag ejection acceleration is stable and continuous. The number of airbags has a significant effect on the ejection distance, the output energy, and the stability of the airbag collision testbed. A more number of airbags means a greater ejection distance and more effective energy output. The energy of a three-airbag catapult is 6 times than that of a one-airbag catapult. The more the number of airbags is, the larger the lateral displacement of the airbag ends is. However, the swing displacement of a three-airbag catapult is not more than 7 mm, and hence a good stability can be ensured in the airbag ejection process.