Injury tolerance of tibia for the car-pedestrian impact

Lower limbs are normally the first contacted body region during car-pedestrian accidents, and easily suffer serious injuries. The previous tibia bending tolerances for pedestrian safety were mainly developed from three-point bending tests on tibia mid-shaft. The tibia tolerances of other locations are still not investigated enough. In addition, tibia loading condition under the car-pedestrian impact should be explored to compare with the three-point bending. This work aims to investigate the injury tolerance of tibia fracture with combined experimental data and numerical simulation. Eleven new reported quasi-static bending tests of tibia mid-shaft, and additional eleven dynamic mid-shaft bending test results in the previous literature were used to define injury risk functions. Furthermore, to investigate the influence of tibia locations on bending tolerance, finite element simulations with lower limb model were implemented according to three-point bending and pedestrian impact conditions. The regressive curve of tibia bending tolerance was obtained from the simulations on the different impact locations, and indicated that tibia fracture tolerance could vary largely due to the impact locations for the car-pedestrian crash.