Comparison of PMHS, WorldSID, and THOR-NT responses in simulated far side impact

Injury to the far side occupant has been demonstrated as a significant portion of the total trauma in side impacts. The objective of the study was to determine the response of PMHS in far side impact configurations, with and without generic countermeasures, and compare responses to the WorldSID and THOR dummies. A far side impact buck was designed for a sled test system that included a center console and three-point belt system. The buck allowed for additional options of generic countermeasures 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 18 tests on six PMHS were done to characterize the far side impact environment at both low (11 km/h) and high (30 km/h) velocities. WorldSID and THOR-NT tests were completed in the same configurations to conduct matched-pair comparisons. For high-speed tests, center console pelvic forces ranged from 3 to 5 kN; thorax or shoulder plate forces (when present) ranged from 3 to 4 kN. Shoulder belt forces were highly dependent on the presence of a thorax or shoulder restraint; without alternate restraint, both inboard and outboard shoulder belt forces were approximately 3 kN. Both dummies had positive and negative biofidelity outcomes. For example, the THOR shoulder against a side restraint produced much higher forces than the PMHS or WorldSID; the WorldSID produced greater pelvic loads in the presence of a shoulder plate than the PMHS or THOR. Both dummies provided good measures of head excursion compared to PMHS across most configurations. Both dummies had difficulty measuring appropriate chest deformations due to belt loading because of measurement device locations. Considerations for countermeasure design should account for the potential for increased injuries to other body regions. For example, in the PMHS tests, a high inboard shoulder belt configuration produced carotid artery trauma. The far side impact environment is unique and there are currently no dummies that are designed specifically to assist countermeasure design. The current test series demonstrated that with some modifications, both the WorldSID and THOR have the potential to function as good human surrogates in far side impact configurations.