Robust restraint system design requires effectiveness across varied
anthropometries. Biofidelity reference datasets of postmortem human surrogates
(PMHS), a necessary component of informing and assessing restraint system
design, exist for the midsize males and small females, but there is limited
research for other anthropometries such as the midsize female and obese
populations. The goal of this study was to evaluate the kinematic and injury
response of midsize female, elderly midsize female, obese female, and obese male
PMHS in upright frontal impacts in a simplified restraint environment. The test
condition in this study was a full-frontal 30 km/h impact. The test fixture
consisted of a rigid seat, knee bolster, footpan, a custom 3 kN shoulder belt
force limiter, and separate shoulder and lap belts. Twelve tests were performed
with PMHS of varied anthropometries: three per occupant type (midsize female,
elderly midsize female, obese female, and obese male). The restraint environment
limited the movement of the lower extremities, isolating the thoracic response.
Shoulder belt lengths and positioning varied by occupant type. Peak shoulder
belt force values ranged between 2.8 and 4.4 kN. Differences in soft tissue
distribution (including the hips, abdomen, and breasts) affected both the
pre-test path of the shoulder belt on the thorax and the belt’s subsequent
motion relative to the thorax during the test. Rib fractures were observed
across all four occupant types ranging from 0 to 19 fractures. Occupant
anthropometry affected the impact and injury response of the PMHS in this study,
demonstrating the breadth of the population over which restraint system
robustness is required.
