Head Restraint Mechanism For Reducing Risk Of Injury In High Acceleration Crash Events

A consideration of simple Newtonian mechanics shows that the lighter of two colliding vehicles will experience a greater change of velocity.Empirical studies have demonstrated that this higher ‘delta-V' contributes to a mass-ratio to fatality-risk relationship that scales to the power of 3.8.Despite this,lighter passenger vehicles generally employ the same restraint systems as their heavier counterparts.Although race car restraint systems have proved extremely effective at increasing survivability in high acceleration crashes,such systems are uncomfortable and are not designed to accommodate a range of occupant sizes and seating positions.In this thesis,a new type of head and neck restraint is introduced which uses a system of support plates and an airbag stowed in the roof of the vehicle.A rigid body model was developed to evaluate the requirements of an airbag inflator that can quickly deploy the system in a side impact.An airbag with a rate of pressure increase approximately four times that of a standard frontal airbag was found to be sufficient to deploy the system within 15 ms.The system is expected to be useful in reducing injury risk for occupants of the sub 450 kg quadricycle category of vehicles which are expected to become increasingly popular in Europe.