Considerations of Bio-fidelity Corridors for Lateral Impacts

Developing an effective side impact ATD for assessing vehicle impact responses requires a method for evaluating that ATD's bio-fidelity. ISO/TR9790 has been in existence for some years to serve that purpose. Recently, NHTSA sponsored a research project on the post-mortem human subjects (PMHS) responses subjected to side impact conditions. Based on those newly available PMHS data, Maltese generated a new approach for creating bio-fidelity corridors for human surrogates. The approach incorporates the time factor into the evaluation equation and automates the process (Maltese et al. 2002). This paper serves as the first attempt to look closely at the new bio-fidelity corridor generation process (hereafter referred as the Maltese approach) with respect to its validity, effectiveness, as well as its practicality. The effect of mass scaling was first examined in order to ensure the integrity of the data. The time alignment scheme and the formation of the corridors were then tested. The Maltese approach seems to represent the PMHS test responses. It appears to have some drawbacks due to the complexity of the PMHS responses. The approach works better for unimodal responses but does not produce unique solutions for all sets of time histories. This study also shows that the Maltese approach has merit by taking the time shift into account. The new approach statistically evaluates side impact ATDs for a large portion of the time period and has a well defined numerical procedure that reduces some of the subjectivity seen in ISO/TR9790. Some possible modifications aimed at further simplifying the procedure, improving the efficiency of the approach and eliminating the numerical problems are also studied and outlined in this paper.