Study of Advanced Occupant Models to Quantify Injury Risk for eVTOL Vehicles

Urban transportation is currently evolving from traditional ground-based vehicles to include air-based electric vertical take-off and landing (eVTOL) vehicles. These new eVTOL vehicles are designed to be small, lightweight, and eventually autonomously operable without user intervention. Anthropomorphic test devices (ATDs) are used in aerospace crashworthiness standards to quantify occupant injury risk and develop improved safety designs for emergency landing situations, despite their development many decades ago. ATD technology has continued to evolve, leading to a host of newer and more biofidelic ATDs, such as the test device for human occupant restraint (THOR). Increased computing power has also allowed for detailed computational human body models (HBMs) to be created, such as the Global Human Body Model Consortium (GHBMC). This study aims to assess the capability of both GHBMC and new ATD designs to identify injury mechanisms within eVTOL-relevant emergency landing conditions. Finite element analyses, using GHBMC, HBM, and THOR ATD models, were used to expand upon full-vehicle and seat-level impact testing to look at the effects of occupant model configurations on injury prediction. Of these test conditions, four crash pulses were implemented to a rigid seat, with two of those also being implemented in a generic composite seat and a NASA-designed energy-absorbing seat. Further exploration was performed by altering the position of the GHBMC into a relaxed and upright position. As expected, the GHBMC models are much more deformable than the ATDs and exhibit a higher distribution of forces and increased sensitivity to the duration of acceleration pulses. Both occupant models incorporated into this study identified key mechanisms for injury that should be considered for passenger safety in the development of these novel aircraft. In addition, this study demonstrated the value of FE modeling for running a variety of complex human surrogate impact simulations to identify potential injury mechanisms for consideration in the regulation and development of new aircraft. Continued research in this field to validate these models will lead to safer aircraft and more comprehensive safety measures.