Abstract:

Lumbar injuries caused by axial impact often occur in frontal crash, the explosion of military vehicles at the bottom and pilot ejection, which lead to paraplegia. Finite element method was used in simulation of dropping conditions with Hybrid III 50th Dummy model. Four factors affecting human lumbar spine injuries were
put forward including impact velocity, ground angle, cushion thickness and friction coefficient with analysing the sensitivity of each factor the four. The results show that the impact velocity and the cushion thickness have great influence on lumbar injuries, and other factors are not significant. The lumbar injury risk increases with impact velocity increase and decreases with cushion thickness increase. Lumbar has a risk of fracture when the impact velocity is 6 m/s and above, or the cushion thickness is 100 mm and below. These results can help to improve the protection of lumbar which injured by axial force in the accident. For example, increase the cushion thickness, reduce contact friction and increase impact angle.

Key words: vehicle crashes ,  lumbar injuries , drop ,  dummy model , finite element analysis