Measurement and assessment of passenger vehicle compatibility in front and side collisions

The objective of vehicle crash compatibility is the optimisation of vehicle design to minimise the total number of injuries and fatalities that occur in all collisions in the accident environment. It is hence distinguished from traditional perceptions of occupant protection in that it requires vehicle designs to be optimised to protect other road users in addition to the vehicle’s own occupants. The aim of this thesis is to define an objective method to assess the compatibility of a front-to-front or front-to-side collision between two passenger vehicles.

Accident statistics from the German In-Depth Accident Survey (GIDAS) relational database are analysed to determine the significance of passenger vehicle occupant casualties with regards to other road users and also to set priorities for the assessment of compatibility between passenger vehicles. Collision obstacles, configurations, velocity, and vehicle mass are analysed with respect to the Abbreviated Injury Scale (AIS).

A method is defined to objectively measure compatibility by comparing the post-collision deformations from a vehicle-to-vehicle collision with the post-collision deformations from a series of vehicle-to-barrier collisions. The result is quantified with respect to injury data derived from the accident statistics.

Ideal models of horizontal and vertical structural homogeneity are developed and applied in front-to-front and front-to-side collision simulations between a mid-sized passenger car and a large Sports Utility Vehicle (SUV). Hence, for the first time, independent conclusions are able to be drawn based on the effects of ideal horizontal homogeneity and ideal vertical homogeneity. The effects of front-end structural homogeneity are also investigated in combination with changes to the stiffness of various components in the vehicle side structure.

Finally, the findings of the simulations and the accident analysis are used to describe the necessary characteristics for a test procedure to assess a vehicle’s compatibility. The merits of existing test procedures are discussed, and alternative concepts are proposed.