Biomechanical modelling of occupant induced centrifugal loading on automotive glazing

Accurately determining the occupant loading onto the side glazing and surrounding structures during collisions is an important component of the development of occupant ejection mitigation systems. This paper details simulations performed in order to determine the centrifugal loading of a typical adult occupant against adjacent portions of the vehicle during rollover. This paper estimates centrifugal force vectors and the effective mass of a 50th percentile male on the glazing during the airborne (unconstrained) portion of rollovers of increasing severity. An LS-DYNA model of a Ford Bronco II sport utility vehicle was developed. This finite element (FE) model was then coupled with the MADYMO Hybrid III 50th percentile Anthropomorphic Test Dummy (ATD). Progressively greater centrifugal accelerations acted upon the occupant and vehicle in order to acquire the loads on the glazing and door. The effective mass of the ATD interacting with the glazing was calculated using interfacial contact forces. The results of this investigation show a non-linear increase in loading upon the glazing, door and B-pillar with increasing rotational velocity, and that the effective mass of the occupant on the glazing is highest at a roll velocity of 270 deg/sec.