While pre-crash braking reduced organ injury risk in animals in sled-testing, it is known to increase occupant forward excursion during pre-crash, thereby increasing risk of injurious interactions with vehicle interior in crashes. The combined use of pre-crash braking, like Autonomous Emergency Braking (AEB), with prepretensioner (PPT) might reduce both risks. The study objective, therefore, was to quantify reductions in forward excursions and loading on liver and spleen using simulations. The detailed GHBMC-M50 model was positioned in a simplified sled and restrained by a standard three-point belt system with a pyro-pretensioner and a 4 kN load limiter. Three cases of full-frontal impact at 56 kph were simulated: without AEB and PPT (0 g+0 N); AEB without PPT (1 g+0 N); and with AEB and 350 N PPT (1 g+350 N). The results showed that a standard belt system during AEB in 1 g+0 N reduced inertial load on liver and spleen, but resulted in higher forward excursion compared to no AEB in 0 g+0 N. Adding PPT counteracted occupant’s forward motion during AEB in 1 g+350 N and held it in upright posture before the crash. Inertial loading on both organs was reduced against 0 g+0 N, but was higher compared to 1 g+0 N. Therefore, PPT appeared to reduce abdominal organ loading without compromising forward excursion.
Keywords:
Abdominal organ response; GHBMC model; in-crash; pre-crash braking; pre-pretensioner