Biomechanical Analysis of Late Airbag Deployment in Motor Vehicle Crashes Using Computer Simulation

Abstract

Motor vehicle collisions frequently result in serious or fatal inuries to occupants [1–4]. Frontal collisions are amongst the most severe types of accidents. The use of safety systems such as seat belts and airbags has been shown to reduce the severity of injuries sustained by occupants [5–10]. It is well known that frontal airbags act as supplemental restraints to seat belts in protecting occupants. Airbag deployment occurs through a reaction of chemicals in the inflator that rapidly produces gas and fills the canvas bag. The filled bag acts a cushion between the occupant and the vehicle’s interior components. The supplemental restraint provided by the airbag increases the amount of time and distance over which the occupant’s body decelerates, and accordingly reduces the potential for injury. The time at which the airbag deployment is initiated during the crash sequence can have an effect on the nature of the contact between occupant and airbag. Though properly timed, frontal airbags have been shown to reduce injuries sustained to occupants[11], it has been reported that airbags that deploy too late may cause injury[12]. To date, there have been a very limited number of studies that have addressed the biomechanical effects of late airbag deployment. The purpose of this study is to determine the biomechanical effects of late airbag deployment and restraint use on various sizes of occupants through computer simulation.

Study regarding the influence of airbag deployment time on the occupant injury level during a frontal vehicle collision

“…It was observed a percentage increase of the HIC36 value by up to 600% in the event of an airbag deployment delay of 100 ms. If the delay was 150 ms, the gas force inside the airbag "throws" the occupant's head in the rear and it comes in contact with the head restraint causing injury by increased acceleration values of the head [15]. The study at hand follows up this analysis and test new variants including passenger injury risk a seatbelt pretensioning system.…”