Abstract
In this article it is showed an energy absorption system for collision to be applied on ground vehicles, which increases the safety in them. This system is based on increasing the area of vehicle, which takes up by means of energy of deformation, the liberated kinetic energy in case of collision. In fact, in the current vehicles, the area, which is in charge of taking up the kinetic energy in the collision, corresponds to the area just in the crash. However, by means of this system, not only the area of the impact but also any part of the vehicle could take up the deformation energy. This happens in this way thanks to a load transmission system charged of causing that areas of the vehicle which do not correspond to the impact area, receive a requesting in case of collision.
First of all, It could be thought that the system would increase the rigidity of vehicle and therefore the existent deceleration in it in the crash. For overcoming this problem, it is introduced a time lapse among the action of different parts of vehicle charged of taking up energy, therefore it is not increased the existent deceleration, in comparison with a vehicle which has not the energy absorption system. Hence a vehicle with this energy absorption system allows that the permanent deformation in it after the crash is reduced, increasing the security related to the no invasion of the survival space, in which the passengers are. Moreover, the existent deceleration in the vehicle with the energy absorption system is located at the same level that a vehicle without the system.
The concept of energy absorption device for collisions can be applied in all kinds of ground vehicles with more than two wheels, as cars, trucks, semi-trailers, buses and trains. At the same time, it is an effective system faced to different types of collisions, as frontal collisions, front-lateral, lateral and rear collisions. An appropriated system disposition is necessary in each case. Meanwhile, the liberated energy in any mentioned collision, not only is transformed in deformation energy in the impact area, but also others take up it zones of the vehicle. For instance, in case of frontal collision of a vehicle incorporating the developed system, the energy absorption will take place not only in the frontal area of the vehicle, but also in the rear one. In this case, of the use of a load transmission system between the different parts of vehicle would be necessary.
In order to verify the validity of developed Energy Absorption System, the University of Zaragoza (Spain) carried out numerical simulations based on the Finite Element Method, using time integration explicit codes. It was analysed the frontal collision at 15 and 55 km/h of an intercity bus with and without the energy absorption system against a rigid wall. At the same time, it was carried out frontal collision tests to 28 km/h. of a prototype vehicle, with and without energy absorption system, in order to confirm its efficiency. These crash tests took place in the facilities of Centro Zaragoza (Spain), with the collaboration on Technological Institute of Aragón (Spain). The results of the crash tests showed the benefits for applying the energy absorption system for vehicles, verifying how it was obtained a reduction in the permanent deformation in the prototype after the impact, keeping the level of maxim deceleration between the prototype with and without absorption system.