Technical Paper
Theoretical Relationship of HIC d to Crush Space for FMVSS-201 Head Impact Tests, and the Effective Use of FEA in Predicting HIC for Design, Verification and Optimization of Countermeasures
1998-09-29
982349
FMVSS 201 requires the HIC_d, calculated from the integration of the time vs. acceleration pulse, in a 14.4 ± 0.5 mph test with a 10 lbs free-motion headform, to be below 1000. To achieve this, the headform should be decelerated through a specified distance. The aim is to derive a theoretical relationship between the HIC_d and the stopping distance, such that for a given baseline HIC_d, the minimum additional crush-space needed to meet the requirements can be quickly determined. Other investigators have derived this relationship assuming a simplified, triangular wave function for the pulse. This study incorporates a more practical haversine wave function, and further develops it to include both positively and negatively skewed haversine wave forms. This represents the complete range of actual tests, with varying waveform efficiencies.
