Conviction of Frontal Offset-Crashes into Sliding Collisions

In most cases frontal real world crashes are offset configurations. The impacting cars meet together only with an overlap less than 100%. With today`s vehicles even offset configurations with small overlap result in so called full impacts, where no sliding between the two crash partner occurs. In such collisions the two car structures have to absorb a huge amount of the kinetic energy of both vehicles before the impact. This effect is caused by the situation, that especially the longitudinal beams and the wheels tend to stick together even in cases with small overlap. Today`s crash test configurations include frontal offset crashes against rigid and deformable barriers. At the moment all car manufacturers pass these tests through full impacts. By converting these crashes into sliding collisions, the change of velocity could be reduced significantly. In addition the vehicle`s deformation is reduced. Transforming frontal offset collisions into sliding collisions would not only reduce the risk of intrusion injuries. It can also help to decrease the load on the passenger`s head and thorax considerably. To reach this target the design of the vehicle`s front structure has to be modified. Special sliding areas have to be constructed. Also the position of the front wheels and their defined displacement has to be taken into account. Investigations of the requirements of such a structure will be the most important part of the project. The aim of the project should be reached by using mathematical tools (finite elements, multi body systems, accident reconstruction) as well as physical experiments. The realisation should be proofed and a proposal of constructions will be given. Also the influence on the statistics of today`s real world car accidents and the possible avoidance of severe injuries should be shown.

Summary As shown in many statistics of car accidents most real world crashes are so called frontal offset - collisions with an overlap of less than 50%. Caused by matter of construction of todays vehicles also crashes with small lateral overlap end in a full hanging of both cars and therefore lead to heavy loads and severe injuries. A conversion into a sliding collision where the vehicles get much less decelerations and deformations will lead to a significant reduction of the injury risk of the car occupants. During this project a system was developed which leads to sliding collisions and which can be integrated into future cares without serious structure changes of the wheel suspension or car body. Description of the project The main target of the project was to reduce the injury risk by reducing the deformation of the cars and the velocity change. This can be reached by the conversion of a standard frontal offset crash into a sliding collision. To stimulate also the interest of the car manufacturers it was important to have as little changes as possible in the design of the car body. Using mathematical simulation tools like multi body systems, finite elements method and accident reconstruction together with Magna Steyr a system was developed which allows, integrated into todays cars, sliding collisions up to an overlap of 25%. In addition the technical design of such a system was proposed, too. Finally the simulations were validated by two real world crash tests. Results After several different sliding mechanisms were analysed the optimum was found in a rotating wheel on the crash side of the car. A pyrotechnical triggered cylinder integrated into the steering link leads to a rotation of the wheel as soon as a precrash sensor signals an unavoidable collision. On the one hand the wheel then works as a shield against intrusions into the toe pan and on the other hand it is a slide plane which deflects the car from an other car or a barrier. Using such a system would cause a serious reduction of the injury risk and of intrusions in the car body. This leads to lower costs for the health system and also for car repairs. There is an intention to give lectures for the car manufacturers which introduce this sliding collision system to the automotive industries. Furthermore the project will be continued within K-Plus (Virtual Vehicle) together with Magna Steyr.