STUDY OF VEHICLE OCCUPANTS INJURY RISK IN SIDE COLLISIONS BASED ON VEHICLE DEFORMATIONS

摘要

As statistics have it, side collisions hold the second position after front collisions in a classification of types of vehicle collisions made according to occupants' injury risk. The occupants' injury risk greatly depends on how the impact energy dissipates by the deformation of the vehicle structure, and how the passenger's vital space is maintained after the collision, so that they should not be crushed inside the vehicle. To ensure the safety of the vehicle occupants is improved, the study mainly focuses on how a vehicle structure behaves to impact and the protection of occupants. The main objective of the work is to evaluate a method to compare the residual crush of the side body involved in side collisions to other vehicles and investigate whether the crushed profile has an effect on the occupants' injury outcome. The analysis and synthesis of the results are intended to improve car crash performances, truly contributing to widen the knowledge scientific basis that is used to identify new solutions for car safety. The work method resides in analysing a wide range of side vehicle to vehicle collisions by a method intended to investigate vehicles, measuring residual crush amplitude on the vehicle side in a series of preset points called generic points and correlating them to occupants' injury to determine the occurrence of such injuries. The analysis is performed for several typical cases of side collision and the results are assessed for each specific case, in order to determine correlations between the shape of the deformed profile and the occupant degree of injury. Results of the study show a high occupant injury risk in cases of perpendicular side collision, for Δv>25 km/h or large width deformation profile. The amplitude of vehicle side deformations occurred on the front door and its intrusions in the occupants' area explain leg injuries AIS3+ level for the front seat occupants. Severe injuries of the thorax are apparently caused by large intrusion along the entire length of the passengers' compartment and/or greater intrusion of the B-pillar on the pelvis level than the thorax level. The method used proves useful as it is possible to integrate measurements performed on the crush profile of the vehicle in a generic points system applicable for most cars. The method presents however the inconvenient of transposing already made measurements into data specific to the generic points system.