Influence of Mass Ratio and Structural Compatibility on the Severity of Injuries Sustained by the Near Side Occupants in Car-to-Car Side Collisions

In 1344 car-to-car side collisions, the risk of serious or fatal injury to the occupants of struck vehicles seem to increase proportionally to the difference in mass ratios in favor of the striking vehicle.

However, in-depth analysis of 63 collisions during which the impact occurred on the side panel of the passenger compartment reveals that the difference in mass ratios is not the principal determinant of injury severity.

The frequency and severity of injuries correlates better with the amount of intrusion of the side panel, a type of intrusion which occurs almost systematically, and even at low impact speed, when the bumper and structure in front of the side rail of the striking car override the rocker panel of the struck car.

We shall show the relationship between the severity of chest, abdominal and pelvic injuries sustained by occupants seated perpendicularly to the intruding panel and the following parameters:

• mass ratio
• compatibility of the relative heights of the stiffest elements involved in the impact
• impact speed
• ΔV of the struck car
• intrusion

We shall indicate the structural modifications which might improve protection of occupants involved in side collision with another car.