Vehicle Crash Simulations with Morphed GHBMC Human Models of Different Stature, BMI, and Age

In motor vehicle crashes, occupants who are elderly and obese are at increased risk of death and serious injury compared with young, non-obese adults. However, current procedures for evaluating vehicle safety designs are mainly conducted with crash test dummies and computational dummy/human models representing only a few sizes of young and non-obese occupants, namely large-male, mid-size male, and small-female. In this paper we present a preliminary modeling study to show the potential effects of aging and obesity on injury risk trends. We first developed a set of 12 male human body models (HBMs) of different stature (1750 mm and 1880 mm), body mass index (BMI) (25, 30 and 35) and age (30 and 70 YO), by morphing the Global Human Body Model Consortium (GHBMC) mid-size male model into target geometries defined by the statistical skeleton and external body surface models developed previously. Next, these 12 morphed HBMs were integrated into a vehicle NCAP crash (35mph frontal) sled model through a series of steps for HBM posture adjustment and seatbelt fitting based on a driving posture model developed previously. Finally, from the simulation results, we identified injury risk trends due to different body sizes. The following trends were found: 1) taller occupants tended to have a higher risk of head injuries; 2) higher BMI occupants tended to have higher femur/pelvis injury risk; 3) older occupants tended to have higher thorax and femur injury risks due to their lower injury tolerance. Although the simulations in the current study were only based on one generic vehicle and the results may not be generalized for the whole fleet, this study did demonstrate that occupant characteristics had profound impact in injury risks in frontal crashes.