Evaluation of Pedestrian Subsystem Test Method Using Legform and Upper Legform Impactors for Assessment of High-Bumper Vehicle Aggressiveness

Abstract

In accidents involving sports utility vehicles (SUVs), injuries to pedestrian leg, knee ligaments, and femur are likely to occur. Therefore, the European Enhanced Vehicle Safety Committee proposed two subsystem test methods for evaluation of SUV bumper aggressiveness. Such evaluation can be conducted by means of either a legform impactor (evaluation of risk of knee and tibia injury), or an upper legform impactor (evaluation of risk of thigh and pelvis injury) test. Each of these two test methods has its own injury criteria and injury acceptance levels. Therefore, the first objective of this research is to clarify any differences between the test results obtained when evaluating SUV bumper aggressiveness by means of these two impactors. The second objective is to determine whether or not a legform impactor can be applied to estimate the risk of femur fracture, and if an upper legform impactor can be used to estimate the risk of knee ligament injury. The present results indicate the test method using an upper legform impactor yields higher ratios of injury criteria to the relevant EEVC/WG17 injury acceptance levels than by using a legform impactor. Thus, the upper legform impactor test rates an SUV bumper as more aggressive than the legform impactor test. The present study suggests the lower leg acceleration obtained by the legform impactor can be used to adequately assess the risk of femur fracture, when evaluating the aggressiveness of an SUV bumper using proposed injury acceptance levels reported in the literature. Similarly, the impact force obtained by the upper legform impactor can be used to assess the risk of cruciate ligament injury.

Keywords:

• Bumper Aggressiveness
• EEVC
• Injury Criteria
• Leg Injury
• Pedestrian Safety
• Sport Utility Vehicle

ACKNOWLEDGMENTS

The author is indebted to Tsutomu Doi, Assistant Professor of Ibaraki Christian University, for his incisive suggestions regarding the statistical analysis, to Dr. Adam Wittek of JARI for his valuable comments, and to Mr. Masaru Takabayashi and Mr. Hiroyuki Jimbo of JARI for conducting the impactor tests.

The current study was funded by the Japan Automobile Standards Internationalization Center.

Notes

*Lower leg acceleration was measured by legform impactor to evaluate tibia fracture possibility.

*Alternative injury criteria.