Worldsid assessment of far side impact countermeasures.

Abstract

Far side impact trauma has been demonstrated as a significant portion of the total trauma in side impacts. The objective of the study was to assess the potential usefulness of countermeasures and assess the trade-offs associated with generic countermeasure design. Because the WorldSID dummy has demonstrated promise as a potential far side impact dummy, it was chosen to assess countermeasures in this mode. A unique far side impact buck was designed for a sled test system that included, as a standard configuration, a center console and outboard three-point belt system. This configuration assumed a left side driver with a right side impact. The buck allowed for additional options of generic restraints including shoulder or thorax plates or an inboard shoulder belt. The entire buck could be mounted on the sled in either a 90-degree (3-o'clock PDOF) or a 60-degree (2-o'clock PDOF) orientation. A total of 19 WorldSID tests were completed. The inboard shoulder belt configuration produced high shear forces in the lower neck (2430 N) when the belt position was placed over the mid portion of the neck. Shear forces were reduced and of opposite sign when the inboard belt position was horizontal and over the shoulder; forces were similar to the standard outboard belt configuration (830 - 1100 N). A shoulder or thorax restraint was effective in limiting the head excursion, but each caused significant displacement at the corresponding region on the dummy. A shoulder restraint resulted in shoulder displacements of 30 - 43 mm. A thorax restraint caused thorax deflections of 39 - 64 mm. Inboard restraints for far side impacts can be effective in reducing head excursion but the specific design and placement of these restraints determine their overall injury mitigating characteristics.