The reconstruction of vehicle accidents can be seen as an important science. On one hand the total number of worldwide accidents is still increasing in many industrialised countries, on the other hand huge new markets especially in Asia are growing significantly. Currently according to publications of WHO, more than 1 Million people are killed annually. Thus the reconstruction of accidents is of great importance to determine the cause of the individual accidents. Only by detailed analysis of the individual cases in combination with statistical evaluations further reductions can be reached. Due to the high burden caused by accidents, the reconstruction of car accidents plays also a major role in the support the crime and civil legal actions.
The science of accident reconstruction is a well established technology which has been used for several decades to study and analyse the motion of vehicles before during and after the impact. It is based on physical evidence like marks on the roads, deformations of vehicles and witness statements. In the past mainly simplified kinematic analysis where performed to determine velocity changes of the involved vehicles during braking or sliding, by estimating average decelerations. The contact phase was analysed by using the basic impact equations like conservation of momentum, angular momentum and energy.
Due to the availability of powerful computers and software programs its now possible to use much more sophisticated algorithms. Both multi body and simplified Finite Element approaches are being used. For analysis of the contact phase the Finite Element method has been established as standard development tool in the car industry to determine vehicle deformations and occupant loads. For the analysis of the vehicle motion mainly prior to impact or in critical driving situations, detailed Multibody models of suspension and tire characteristics are being used.
For the reconstruction of car accidents normally such detailed vehicle parameters and models are not available. Neither detailed Finite Element models of the cars nor detailed knowledge about the suspension and tire properties can be obtained. Cars involved in car accidents are also normally not evaluated prior to the collision. Thus for the reconstruction of car accidents the variation of the main influencing parameters is of great importance.
This is also the reason why more simplified but more general models of the vehicles are generally being used for accident reconstruction compared to vehicle development. But powerful optimisation and variation technologies nowadays allow the evaluation of different influence parameters efficiently. Never the less, like in automotive development, the validation of all models is of great importance.
This booklet should show some of the methods currently applied in accident reconstruction. It covers various fields ranging from conventional reconstruction methods to the application optimisation methods. Special emphasis has also been put on the reconstruction of pedestrian accidents as well as the motion and loading of vehicle occupants during collisions.
As such the booklet can be seen as valuable tool for the analyst giving an overview about new and advanced reconstruction and simulation technologies.