Active energy absorber
For some years now, vehicle manufacturers have been expanding their model range with a variety of different vehicles and derivatives. Due to the applicable approval standards, vehicle manufacturers design their body structures mainly in terms of vehicle mass or kinetic energy.
Smaller vehicles may therefore be at a disadvantage compared to heavier vehicles, as they generally have less mass and shorter front weighbridges. Conventional side members designed for crease buckling do not offer the possibility of active adaptation to different accident scenarios.
To meet this challenge, a side member was developed at DLR-Institut für Fahrzeugkonzepte in which the crash behaviour can be actively adapted to different, expected and detected accident situations. Kinetic energy is converted by chipping the surface of a telescopic tube. By adjusting the cutting depth or the cutting volume, the energy conversion capacity and the longitudinal force can be varied continuously and in less than 120 milliseconds. This adaptation of the crash behaviour can significantly improve compatibility between vehicles of different masses without having to accept disadvantages in collisions with rigid obstacles.
At lower speeds and rigid obstacles, it is also possible to reduce the deceleration acting on the occupants to a necessary minimum by selectively reducing the force level. In addition, this technology offers the possibility to specifically create an asymmetric load distribution by adjusting the force levels of the two longitudinal beams differently.
Simulations carried out at DLR show that especially in side impact situations, such as when there is a simultaneous impact on stiff and solid structures such as the B-pillar on the one hand and on rather soft structures such as the door on the other, this technology offers benefits with regard to intrusions on the other accident object. It has thus been possible to develop and validate in tests a system that offers benefits for all parties involved in individual accident situations.
