Validation of Pedestrian Lower Limb Injury Assessment using Subsystem Impactors

Although the biofidelity improvements of the pedestrian legform called the Flexible Pedestrian Legform Impactor (FlexPLI) relative to the conventional legform (EEVC legform) have been shown in past studies, their effects on the evaluation of safety performance of vehicles have not been clarified in a quantitative and comprehensive manner. The goal of this study was to clarify the difference in the results of the tibia and knee injury assessment between the two legforms, and the factors of the difference from a viewpoint of their stiffness characteristics and injury measures. Impact simulations were conducted at 40 km/h using the finite element (FE) models of the two legforms and a human body, along with 18 simplified vehicle models. The correlation between the peak tibia and knee injury measures from the human model and those from the two legform models showed significant improvements of the FlexPLI for tibia fracture and ACL failure prediction. Additional impact simulations using simplified vehicle models showed that both the stiffness of the tibia and the use of the acceleration as an injury measure are the factors for the poor correlation of tibia injury measures of the EEVC legform.