Can pedestrian headform test results reflect the distribution of head injuries in the real world? 2024-01-2515

Wrap around distance (WAD) is an important index to evaluate the contact position between pedestrian head and vehicle, and is also one of the key parameters of pedestrian accident reconstruction. The purpose of this paper is to explore whether the pedestrian headform testcan reflect the distribution of head injury in the real world. Firstly, in order to study the distribution of pedestrian head WAD in road accidents in China, a head WAD prediction model was established using logistic regression based on pedestrian height and vehicle collision speed. Secondly, in order to study the distribution of the risk of severe head injuries among pedestrians in accidents, the frequency of pedestrian head impact and the proportion of pedestrian head injury were counted respectively for sedans and SUVs. Subsequently, a risk curve for severe head injuries was constructed based on the head impact frequency and the proportion of severe injuries, utilizing a method that incorporates joint probability. Finally, to investigate the relationship between the headform test results and the distribution of severe head injury risks among pedestrians in road traffic accidents in China, a meticulous regional division of the head WAD was conducted based on the vehicle's front structure. A qualitative comparison was made between the distribution of headform test results in that area and the distribution of pedestrian injuries in the real world within that specific region. The results indicate that the location of pedestrian head impacts is primarily concentrated within the range of WAD 1500 mm to WAD 2300 mm. When pedestrians collide with sedans, the peak frequency of head impact occurs at WAD 1900 mm, whereas in collisions with SUVs, this peak occurs at WAD 1700 mm. In the areas of sedan windshields and A-pillars, as well as the rear portion of SUV hoods and windshield wiper regions, pedestrians' heads are most susceptible to severe injuries. It is noteworthy that within the WAD1000-WAD1500 mm range, the risk of severe head injuries for pedestrians is nearly zero. This study, through the analysis of severe head injury distribution among pedestrians in China, assessed the effectiveness and applicability of The China Insurance Automotive Safety Index (C-IASI) headform test. It provides targeted recommendations for the enhancement of the C-IASI pedestrian assessment protocol and offers crucial reference for optimizing the design of vehicle front structures.